Cellulose Technology Research 9780841202481, 9780841201774, 0-8412-0248-6

Table of contents :
Title Page......Page 1
Copyright......Page 2
ACS Symposium Series......Page 3
FOREWORD......Page 4
PdftkEmptyString......Page 0
PREFACE......Page 5
1 Colloidal Microcrystalline Celluloses......Page 6
Literature Cited......Page 13
Introduction......Page 14
Microwave and Its Utilization......Page 15
Continuous Process Outline......Page 20
Typical Thiocarbonation Conditions......Page 21
Post-thiocarbonation Treatments......Page 22
Typical Monomer Formulations......Page 24
"PEPM" Description......Page 25
Grafted Product Properties......Page 26
Summary......Page 29
Literature Cited......Page 30
Introduction......Page 32
Literature Cited......Page 43
Early Works on Silylation of Cellulose......Page 44
Silylation With Bis(trimethylsilyl)-Acetamide (BSA)......Page 47
Trimethylsilyl Ethyl Cellulose......Page 48
Silylation With Trimethylsilylacetamide......Page 49
Properties of Silyl Celluloses......Page 50
Literature Cited......Page 54
Introduction......Page 56
Experimental......Page 57
Results and Discussion......Page 62
Acknowledgements......Page 78
Literature Cited......Page 79
Animal Feeding Studies......Page 80
Pretreatments to Increase Digestibility......Page 85
Pulp and Papermill Residues and Wood Pulp......Page 98
Summary......Page 107
Literature Cited......Page 109
Abstract......Page 111
Conclusions......Page 116
Literature Cited......Page 118
Appendix Β......Page 119
Procedure......Page 120
8 Reaction of Alkylene Oxides with Wood......Page 121
Introduction......Page 130
Results......Page 131
Discussion......Page 136
Experimental......Page 145
Literature Cited......Page 150
INTRODUCTION......Page 152
MORPHOLOGY OF THE POLYETHYLENE ENCAPSULANT......Page 154
PHYSICAL PROPERTIES OF ENCAPSULATED PAPER......Page 155
CONTINUOUS ENCAPSULATION PROCESS FOR FIBROUS WEBS......Page 158
CONCLUSIONS......Page 162
LITERATURE CITED......Page 164
Introduction......Page 165
Materials and Methods.......Page 167
Results and Discussion......Page 168
Literature Cited......Page 174
12 Marine Polymers, V. Modification of Paper with Partially Deacetylated Chitin......Page 177
Methods.......Page 178
Results and Discussion......Page 179
Literature Cited......Page 185
Introduction......Page 186
Experimental......Page 189
Results and Discussion......Page 190
Conclusions......Page 198
Literature Cited......Page 199
C......Page 200
E......Page 201
K......Page 202
P......Page 203
V......Page 204
Z......Page 205

Citation preview

Cellulose Technology Research Albin F. Turbak,

Editor

A symposium sponsored by the Cellulose, Paper, and Textile Division at the 168th Meeting of the American Chemical Society, Atlantic City, N.J., September 11-12, 1974

ACS

SYMPOSIUM

SERIES

AMERICAN CHEMICAL SOCIETY WASHINGTON, D. C. 1975

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

10

Data

Library of Congress Cellulose technology research.

(ACS symposium series; 10) Includes bibliographical references and index. 1. Cellulose—Congresses. I.

Turbak, Albin F., 1929-

ical

Society.

III.

Series:

series;

Cellulose,

Paper,

ed. II. American Chemand Textile

American Chemical Society.

Division.

ACS symposium

10.

TS933.C4C43

674'. 134

ISBN 0-8412-0248-6

75-2021 ACSMC8 10 1-353

Copyright © 1975 American Chemical Society A l l Rights Reserved PRINTED I N T H E UNITED STATES O F AMERICA

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

ACS Symposium Series Robert

F.

Gould,

Series Editor

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

FOREWORD The ACS SYMPOSIUM SERIES was founded in 1974 to provide

a medium for publishing symposia quickly in book form. The format of the SERIE IN CHEMISTRY SERIES papers are not typeset but are reproduced as they are submitted by the authors in camera-ready form. As a further means of saving time, the papers are not edited or reviewed except by the symposium chairman, who becomes editor of the book. Papers published in the ACS SYMPOSIUM SERIES are original contributions not published elsewhere in whole or major part and include reports of research as well as reviews since symposia may embrace both types of presentation.

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

PREFACE Recent oil shortages have pronounced an end to the era of cheap petrochemicals. The current furor over vinyl chloride toxicity coupled with the biodegradability problems of many petrochemical-based materials finally have created a long overdue awareness that synthetics may have very serious shortcomings and may not represent the total panacea which large oil interests and their Madison Avenue marketing agencies have incessantl These cost and health factors have aroused a renewed appreciation for natural-product materials. As a result, cellulose and cellulose-based products are presently enjoying an increased research impetus. Cellulose is without a doubt not only the most abundant polymer in the world but also the most versatile. Its present commercial use in manufacturing artificial kidneys, aspirins, hot dogs, ice cream, paints, diapers, contact lens lubricants, fibers, plastics, and a host of other products clearly demonstrates that it can be adapted by creative scientists to serve practically any desired function. This symposium was held in an effort to present a cross section of recent research in the cellulose area. Judging by the scope of these efforts, much more work is undoubtedly underway which is not presently available for public disclosure. The contributions in this volume, however, adequately demonstrate that cellulose researchers are diligently pursuing efforts to contribute basic knowledge and to capitalize on the opportunities being created by the present dynamic market needs and conditions. Each author is individually responsible for his overall claims since it is ACS policy for this series that the symposium chairman not review the final submissions in order to expedite publication. I would like to thank each of the participants for their kind cooperation, and I hope that this joint effort proves useful and stimulating to fellow researchers. ITT Rayonier, Inc. Whippany, N.J. Dec. 23, 1974

ALBIN F . TURBAK

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

1 Colloidal Microcrystalline Celluloses O. A. BATTISTA Research Services Corp., 5280 Trail Lake Drive, Fort Worth, Tex. 76133

The science and technolog few decades have been centered l a r g e l y around the phenomena and the products t h a t r e s u l t from p r e c i p i t a t i n g or " f r e e z i n g " long chain molecules i n t o f i x e d matrices l e a d i n g to important commercial s t r u c t u r a l shapes such as f i b e r s , f i l m s , p l a s t i c s , and c o a t i n g s . The b a s i c hypothesis around which the science o f microcrystalline c o l l o i d a l polymer chemistry (1) is u n f o l d i n g n e c e s s i t a t e s t h a t s p e c i f i c r e q u i s i t e s must be met; it is i n the d e l i b e r a t e combination o f these r e q u i s i t e s t h a t it d e r i v e s its value and originality. Firstly, the molecular weight o f the i n d i v i d u a l long-chain molecules must be high enough; the chain molecules must be long enough t o crystallize out o f s o l u t i o n or from a melt i n t o a two-phase network s t r u c t u r e comprising regions o f high l a t e r a l order (or crystallinity) and regions o f low lateral order (or low crystallinity). Secondly, a pretreatment must be i n v o l v e d which is capable of unhinging or loosening the i n d i v i d u a l m i c r o c r y s t a l s w i t h i n t h e i r precursor matrix without e x c e s s i v e l y s w e l l i n g them or d e s t r o y i n g t h e i r "crystallinity." Thirdly, once the i n d i v i d u a l m i c r o c r y s t a l s have been p r o p e r l y unhinged or loosened w i t h i n the polymer matrix, they must next be f r e e d by the proper k i n d o f mechanical energy. The i n d i v i d u a l microc r y s t a l s , comprising as they do hundreds of long-chain molecules aggregated together, will now act as d i s c r e t e , independent, submicron colloidal particles. C o l l o i d a l m i c r o c r y s t a l l i n e c e l l u l o s e s were the first o f a f a m i l y o f new products t h a t have emerged in recent years (Table 1 ) . The s i z e and shape o f n a t u r a l c e l l u l o s e m i c r o c r y s t a l s are more or l e s s f i x e d by n a t u r e . But wide v a r i a t i o n s in the dimension of such p a r t i c l e s are p o s s i b l e by the appropriate choice o f the n a t u r a l or s y n t h e t i c precursor raw m a t e r i a l (2,3,4). F i g u r e s 1 and 2 are e l e c t r o n micrographs illustrating the 1 In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

CELLULOSE TECHNOLOGY

Table 1 Nine Members o f the M i c r o c r y s t a l Polymer Products Family.

1·

AVICELS

FROM CELLULOSES

2.

AVIAMXLOSES.

3.

AVIBESTS

4.

AVITENES

5.

AVTAMIDES

FROM NYLONS

6.

AVIESTERS

FROM POLYESTERS

7.

AVIOLEFINS..

8.

AVISILKS

FROM NATURAL SILKS

9.

AVIWOOLS

FROM NATURAL WOOLS

....FROM AMYLOSES FRO ...FROM COLLAGENS

...FROM POLYPROPYLENES

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

RESEARCH

1. BATTiSTA

Colloidal Microcrystalline Cellulose

Figure 1.

Microcrystals from wood pulp alpha cellulose

Figure 2.

Microcrystals from rayon tire cord

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

3

4

CELLULOSE TECHNOLOGY RESEARCH

wide spread i n the lengths o f c e l l u l o s e m i c r o c r y s t a l s t h a t i s p o s s i b l e ; m i c r o c r y s t a l s o f wood c e l l u l o s e are compared with m i c r o - c r y s t a l s from v i s c o s e rayon a t the same m a g n i f i c a t i o n . C e l l u l o s e i s h i g h l y c r y s t a l l i n e , uniquely i s o t a c t i c l i n e a r polymer. I t contains m i c r o c r y s t a l s hinged together by t r u e (covalent) molecular bonds. Mechanical beating o f c e l l u l o s e f i b e r s leads only t o a separation o f the f i b r i l s , b u t mechanical energy alone cannot break the 1 , 4 ^ - g l y c o s i d i c bonds i n the molecular chains going from one c r y s t a l l i t e t o the other w i t h i n the f i b r i l with any degree o f e f f e c t i v e n e s s . However, once these hinges i n the i n t e r c o n n e c t i n g areas are broken, i n the case o f c e l l u l o s e by the use o f the hydronium i o n (HC1), then mechanical energy can be used t o cause the i n d i v i d u a l unhinged m i c r o c r y s t a l s t o d i s p e r s e i n t o a l i q u i d medium as i n d i v i d u a l c o l l o i d a l p a r t i c l e s . No m i c r o c r y s t a l s i s so f r e e t o g i v e a smooth, l a r d - l i k e g e l . F i g u r e 3 i l l u s t r a t e s t h e nature o f such aqueous suspensoids f o r m i c r o c r y s t a l l i n e c e l l u l o s e and f o r f i v e other members o f the m i c r o c r y s t a l l i n e polymer family. The m i c r o c r y s t a l s o f pure c e l l u l o s e i n aqueous g e l s do not melt, o f course. T h i s g i v e s such suspensoids a unique f u n c t i o n a l property which makes p o s s i b l e the development o f a new f a m i l y o f convenience foods; m i c r o c r y s t a l l i n e c e l l u l o s e g e l s are used i n precooked cans o f tuna f i s h , ham, chicken, turkey, and even potato salads as h e a t - i n s e n s i t i v e s a l a d d r e s s i n g s . No p r e v i o u s l y known e d i b l e salad d r e s s i n g formulation could stand up under the severe s t e r i l i z a t i o n requirements f o r such canned foods (Figure 4 ) · Table 2 l i s t s the f u n c t i o n a l c o n t r i b u t i o n s o f microc r y s t a l l i n e c e l l u l o s e s i n various product uses. F i g u r e 5 i l l u s t r a t e s the mechanism whereby d r y c o l l o i d a l p a r t i c l e s o f c r y s t a l l i n e c e l l u l o s e , containing numerous " h o l e s " v a r y i n g from 10 A-100 A i n diameter, may be produced· T h i s new porous form o f h i g h l y c r y s t a l l i n e c e l l u l o s e i n powder form i s capable o f absorbing o i l s , greases, c a t a l y s t s , e t c . When a d i l u t e s l u r r y o f a suspension o f i n d i v i d u a l m i c r o c r y s t a l s and l a r g e aggregates o f unhinged m i c r o c r y s t a l s i s spray-dried under proper c o n d i t i o n s , the f r e e m i c r o c r y s t a l s reagglomerate i n t o man-made c l u s t e r s not u n l i k e the manner i n which wooden matchs t i c k s aggregate when p i l e d on a t a b l e top. S t i l l other f a s c i n a t i n g o p p o r t u n i t i e s present themselves when chemistry i s wedded t o these novel c o l l o i d a l macromolecular p a r t i c l e s . F o r example, r e a c t i o n o f the m i c r o c r y s t a l l i n e c e l l u l o s e c r y s t a l s proceeds with p a r t i c u l a r ease and speed. D e r i v a t i v e s can be formed which are a l s o c o l l o i d a l . These are e n t i r e l y new m a t e r i a l s with very d i f f e r e n t p r o p e r t i e s and p o t e n t i a l a p p l i c a t i o n s . A t high degrees o f s u b s t i t u t i o n (D.S.), d e r i v a t i v e s o f m i c r o c r y s t a l l i n e c e l l u l o s e are s u b s t a n t i a l l y the same m a t e r i a l as produced from conventional c e l l u l o s e . A t low

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

1. BATTiSTA

Figure 3.

Colloidal Microcrystalline

Cellulose

Aqueous suspensoids of six classes of microcrystal polymer products

Figure 4. Typical commercial food products containing microcrystalline cellulose

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

5

CELLULOSE TECHNOLOGY RESEARCH

6

Table 2 Puntional P r o p e r t i e s

and End Uses

of M i c r o c r y s t a l l i n e C e l l u l o s e s

Functionality

Product Uses

Emulsion S t a b i l i t y a t High Temperatures

Heat S t a b l e Dressings

Ice-Crystal

Control

S t a b i l i t y To E f f e c t s o f Heat Shock

Frozen Desserts

Improved Body and Texture

Foam S t a b i l i t y Freeze/Thaw

Stability

Whipped Toppings

Improved Body and Texture

G e l l i n g Agent

Low C a l o r i e Dressings

Thickener

Sauces and Gravies

Suspending Agent

Suspension o f Food S o l i d s

Non-Nutritive F i l l e r

Confections Baked Goods

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

1. BATTiSTA

Figure 5.

Colloidal Microcrystalline Cellulose

Reaggregated cellulose microcrystals as porous colloidal particles

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

8

CELLULOSE TECHNOLOGY RESEARCH

degrees o f s u b s t i t u t i o n , where the c o l l o i d a l nature o f the m i c r o c r y s t a l s i s maintained, the d e r i v a t i v e s form unique c o l l o i d a l d i s p e r s i o n s . Dispersions o f a t l e a s t 20% s o l i d s i n water can be produced. These may have the appearance o f greases, ointments, or l o t i o n s , depending on the extent o f topochemical d e r i v a t i z a t i o n and the nature o f the groups added. We have described m i c r o c r y s t a l l i n e c e l l u l o s e s , t h i s f i r s t i n a new species o f c o l l o i d a l m i c r o c r y s t a l polymer products t o reach world-wide commercial success. The knowledge gleaned from converting f i b r o u s c e l l u l o s e s i n t o new, u s e f u l c o l l o i d a l forms has guided us i n t o converting other l i n e a r and c r y s t a l l i n polymer precursors i n t o u s e f u l c o l l o i d a l forms. To date these have i n c l u d e d : c o l l o i d a l m i c r o c r y s t a l l i n e amyloses microc r y s t a l l i n e mineral s i l i c a t e s m i c r o c r y s t a l l i n e polyamides m i c r o c r y s t a l l i n e polypropylenés, m i c r o c r y s t a l l i n e s i l k s , and m i c r o c r y s t a l l i n e wools. A t r e a t i s e encompassing the r e s u l t s o f our research i n the newest f i e l d s o f M i c r o c r y s t a l Polymer Science i n c o l l a b o r a t i o n with many a s s o c i a t e s over a p e r i o d o f 20 years now i s a v a i l a b l e ( 1 ) . T h i s author p r e d i c t s t h a t numerous new avenues o f opportunity remain unexplored f o r the more r e c e n t members o f the m i c r o c r y s t a l polymer science f a m i l y .

Literature Cited

1.

B a t t i s t a , O.A., M i c r o c r y s t a l Polymer Science, A T r e a t i s e . McGraw-Hill Book Co., Inc. 1975.

2.

B a t t i s t a , O. Α., and Smith, P.Α., Ind. Eng. Chem. (1962) 54, (9), 20-29.

3.

B a t t i s t a , O.A., e t al, Ind. Eng. Chem., (1956) 48 333-335.

4.

B a t t i s t a , O.A., and Smith, P.A., U.S. Patent No. 2,978,446 ( L e v e l - o f f D.P. C e l l u l o s e Products), 1961, April 4.

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

2 Continuous Thiocarbonate-Redox Grafting on Cellulosic Substrates W. JAMES BRICKMAN Scott Paper Co., Scott Plaza III, Philadelphia, Pa. 19113

Abstract Permanent fire retardancy, as w e l l as other p r o p e r t i e s , have been g r a f t e d onto moving c e l l u l o s i c substrates as continuous operations. Although e a r l i e r use of batch g r a f t i n g r e q u i r e d r e a c t i o n times of 15 to 120 minutes, continuous g r a f t i n g has been reduced to l e s s than one to three minutes, under conditions which have been designed f o r use in t e x t i l e m i l l s . Example reagent concent r a t i o n s , formulations, r e a c t i o n c o n d i t i o n s and product p r o p e r t i e s illustrate the practicability of the continuous thiocarbonate­ -redox g r a f t i n g r e a c t i o n s t o produce d e s i r e d m o d i f i c a t i o n s on cellulosic materials. F i r e retardant g r a f t s which imparted improved abrasion r e s i s t a n c e , enhanced chemical r e s i s t a n c e ( t o c h l o r i n e bleaches, mildew, b a c t e r i a l attack, e t c . ) , have appeared to be superior to other known methods of making cotton fire r e t a r d a n t . The use of microwave energy and the new monomer, diethylphosphatoe t h y l methacrylate, have had t h e i r r o l e s revealed in production of fire retardancy by the continuous g r a f t i n g process. Introduction Methods f o r batch g r a f t copolymerization of v i n y l monomers on to c e l l u l o s i c m a t e r i a l s by the thiocarbonate-redox method were described e a r l i e r (1-3). Faessinger and Conte discovered that m i l d l y xanthated c e l l u l o s e , i n the presence of v i n y l monomers and o x i d i z i n g c a t a l y s t s , could be g r a f t copolymerized to form a true g r a f t copolymer (4-12). T h i s discovery was f i r s t revealed i n Belgian patents (4,5) i n 1964, followed by a s e r i e s of other patents (6-12) which may have l e d t o some of the p u b l i c a t i o n s of other i n v e s t i g a t o r s i n the f i e l d . Amongst the foremost of these have been our colleagues i n A u s t r i a , H.A. Kraessig and h i s associ a t e s (3,13-15)» whose papers have d e a l t p r i m a r i l y with r e a c t i o n mechanisms and product p r o p e r t i e s of v i s c o s e rayon g r a f t s . Authors i n other parts of the world (16-23) have reported e x p e r i mentation c o n d i t i o n s which, i n many cases, have used batch tech-

9 In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

CELLULOSE TECHNOLOGY

10

RESEARCH

niques s i m i l a r t o those given i n the o r i g i n a l patent examples. When such extreme c o n d i t i o n s are employed, i . e . xanthation t o gamma values o f 6 t o 67, combined with peroxide concentrations up to 10?o owf (on weight of f i b e r ) , degradation of p h y s i c a l propert i e s , homopolymer formation and other problems have r e s u l t e d , which have made such methods u n s u i t a b l e f o r e i t h e r batch or continuous g r a f t i n g of t e x t i l e s . As a r e s u l t , c e r t a i n g e n e r a l i z a t i o n s should be viewed s c e p t i c a l l y , since they only apply i n the regions of the a c t u a l experimentation. They do not apply to e i t h e r the batch c o n d i t i o n s which we have p r e v i o u s l y r e p o r t e d ( l - 3 ^ nor do they apply f o r the continuous g r a f t i n g c o n d i t i o n s given i n t h i s paper. T h i s p r e s e n t a t i o n w i l l f o l l o w the general format: CONTINUOUS ON

THIOCARBONATE-REDOX CF1ÎIILOSI

GRAFTING

1. 2. 3. 4. 5. 6.

BACKGROUND INTRODUCTION MICROWAVE AND ITS UTILIZATION CONTINUOUS PROCESS OUTLINE TYPICAL THIOCARBONATION CONDITIONS POST-THIOCARBONATION TREATMENTS TYPICAL MONOMER FORMULATIONS (a) Fire Retardant (b) Water Dispersible 7. "PEPM" DESCRIPTION 8. GRAFTED PRODUCT PROPERTIES (à) Fire Retardancy (b) Abrasion Resistance (c) Rot Resistance (d) Dispersibilify & Ion Exchange 9.

SUMMARY

Several years ago, we made the i n t e r e s t i n g discovery that the g r a f t copolymerization step could be shortened from the 15 t o 120 minutes range, down to the range of from 3 t o 30 seconds. This was achieved by moving monomer-catalyst impregnated, thiocarbonated, c e l l u l o s i c substrates through a microwave (MW) energy a p p l i cator (24-25). Since t h i s discovery was our key to the development of a continuous g r a f t i n g process at a c c e l e r a t e d speeds, we w i l l give a very b r i e f d e s c r i p t i o n of microwaves and t h e i r a p p l i cation. Microwave and I t s U t i l i z a t i o n In conventional heating systems which i n v o l v e conduction, i n d u c t i o n , or i n f r a r e d r a d i a t i o n , the h i g h l y a c t i v a t e d molecules adjacent to the energy sources must t r a n s f e r t h e i r energy t o t h e i r neighboring molecules through high speed c o l l i s i o n s . Initial temperature d i f f e r e n t i a l s cause thermal gradients and a f i n i t e time i s r e q u i r e d t o uniformly heat the whole mass to r e a c t i o n

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

2. BRiCKMAN

Continuous Thiocarbonate-Redox

11

Grafting

temperatures. Microwaves, on the other hand, simultaneously ex­ c i t e a l l the molecules i n a mass which are capable o f forming d i poles, thereby a v o i d i n g thermal gradients and the attendant migr­ a t i o n problems. The F.G.C. has set aside seven I.S.M. frequencies outside those used f o r communications. These a r e : For INDUSTRIAL, SCIENTIFIC and MEDICAL (I.S.M) Use*

FREQUENCIES

f

MACROWAVE

cm.

13.56

2,200

27.1

i

{

MICROWAVE

WAVELENGTHS

MHz.

I

33

915

12.5

2'450

5.1 1.35

22,125

Φ ~ ASSIGNED BY F.C.C.

The f o l l o w i n g d i s c u s s i o n w i l l be concerned with 2,450 MHz frequency microwave and the e f f e c t s on our aqueous r e a c t i o n system. Microwaves f a l l between macrowaves and i n f r a r e d regions on the electromagnetic spectrum, w i t h wavelengths of approximately three m i l l i m e t e r s t o three meters and frequencies ranging from

r

I

I

1 I

l

I 10

I I0

I

2

I

I 10

s

J. I0

4

I

I

I

I 10*

I ιο·

I I0

7

I

I

I

I

I

•'10*

L 10»

im I0f°

I 10"

1 10

I—I,

e

WAVELENGTH (Χ), Â. MICROWAVE ON THE ELECTROMAGNETIC SPECTRUM

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

ύ£ 10"

CELLULOSE TECHNOLOGY

12

RESEARCH

ca. one hundred m i l l i o n to one hundred b i l l i o n Hertz ( c y c l e s per second). Induction heating u s u a l l y occurs i n conductors, where eddy currents of frequencies not exceeding one Megahertz are used. However, the term " d i e l e c t r i c heating" i s a p p l i e d to use of e l e c ­ tromagnetic waves of from one to 150 MHz. I n f r a r e d heating i s most common f o r conduction heating and encompasses wavelengths from about 3 microns t o 3 m i l l i m e t e r s i n length, with correspond­ ing one hundred b i l l i o n t o 100 t r i l l i o n c y c l e s per second f r e q ­ uencies. ENERGY TRANSFER REGIONS FREQUENCY f Hz. MHz.

INFRARED

MICROWAVE

MACROWAVE

DIELECTRIC

{ {

{

ΙΟ to 10"

to I0 5

10" to I0

I0

10 to 10

10* to 1

8

e

e

a c e t a l s > e s t e r s . The ether bond i s s t a b l e to a c i d s and bases a c i d s and e s t e r s are l a b i l ous that the ether bond i s the most d e s i r a b l e covalent carbonoxygen bond that can be formed. These bonds are more s t a b l e than the g l y c o s i d i c bonds between sugar u n i t s i n the wood p o l y s a c charides so the wood polymers would degrade b e f o r e the g r a f t e d ether. A l l of these bond p o s s i b i l i t i e s consider only covalent bonding with hydroxyl groups; however, other types of chemical attachments are p o s s i b l e . For example, hydrogen bonding, i o n i c i n t e r a c t i o n s , complexing, c h e l a t i o n , and encapsulation are a l l p o s s i b i l i t i e s but l e s s permanent. 9. The hydrophobic nature of the reagent needs to be cons i d e r e d . The chemical added t o the wood must not i n c r e a s e the h y d r o p h i l i c nature of the wood components. I f the h y d r o p h i l i c i t y i s i n c r e a s e d , the s u s c e p t i b i l i t y t o micro-organism a t t a c k i n creases. The more hydrophobic the component can be made, the b e t t e r the s u b s t i t u t e d wood w i l l withstand dimensional changes i n the presence of moisture. 10. S i n g l e s i t e s u b s t i t u t i o n versus polymer formation i s another c o n s i d e r a t i o n . The g r e a t e r the degree o f chemical subs t i t u t i o n (D.S.) of wood components, the b e t t e r i t i s f o r r o t r e s i s t a n c e . So, f o r the most p a r t , a s i n g l e reagent molecule that r e a c t s with a s i n g l e hydroxyl group i s the most d e s i r a b l e . C r o s s l i n k i n g can occur when the reagent contains r e a c t i v e groups which s u b s t i t u t e two hydroxyl groups. C r o s s l i n k i n g can cause the wood to become more b r i t t l e so reagents i n t h i s c l a s s must be chosen c a r e f u l l y . Polymer formation w i t h i n the c e l l w a l l attached to wood components gives good b i o l o g i c a l r e s i s t a n c e and the b u l k i n g a c t i o n of the polymer gives the added property of dimensional s t a b i l i z a t i o n . The disadvantage of polymer formation i s that a higher l e v e l of chemical add-on i s r e q u i r e d f o r the b i o l o g i c a l r e s i s t ance than i n the s i n g l e s i t e r e a c t i o n s . 11. The t r e a t e d wood must s t i l l possess the d e s i r a b l e p r o p e r t i e s of wood. The strength must remain h i g h , no or l i t t l e

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

8.

ROWELL

Alkylene Oxide-Wood

Reactions

119

change i n c o l o r (unless t h i s i s a d e s i r e d requirement), good e l e c t r i c a l i n s u l a t i o n , not dangerous to handle, g l u a b l e , and finishable. In t h i s study, the goal o f chemical m o d i f i c a t i o n i s to i n c r e a s e the decay r e s i s t a n c e and the dimensional s t a b i l i t y of wood. Chemical m o d i f i c a t i o n can a l s o be used to give a d d i t i o n a l improvements such as r e s i s t a n c e to c o r r o s i o n , u l t r a v i o l e t degrad a t i o n , and f i r e . 12. A f i n a l c o n s i d e r a t i o n i s , o f course, the c o s t . In the l a b o r a t o r y experimental stage, i t i s not a major f a c t o r due to the high cost of chemicals when produced on a small s c a l e . For commercialization of a chemical m o d i f i c a t i o n f o r wood, the chemic a l cost i s a very important f a c t o r . On today's market, the l i m i t of chemical cost of t r e a t e d wood f o r r o t r e s i s t a n c e cannot exceed 500 per cubic f o o t . In s p e c i a l t y markets where dimensional stabilization i be 2-3 times h i g h e r . In summary, the chemicals to be l a b o r a t o r y tested must be capable of r e a c t i n g with wood hydroxyls under n e u t r a l or m i l d l y a l k a l i n e c o n d i t i o n s a t temperatures below 120° C. The chemical system should be simple and capable of s w e l l i n g the wood s t r u c ture to f a c i l i t a t e p e n e t r a t i o n . The complete molecule must react q u i c k l y t o the wood components y i e l d i n g s t a b l e chemical bonds and the t r e a t e d wood must s t i l l possess the d e s i r a b l e p r o p e r t i e s of the wood. One r e a c t i o n system which meets the requirements i s the base c a t a l y z e d r e a c t i o n o f a l k y l e n e oxides with hydroxyl group.

R-CH-CH^HOR

1

HQ"

R-CH-CH^-O-R

1

OH The r e a c t i o n i s f a s t , complete, generates no byproducts, forms s t a b l e ether bonds, and i s c a t a l y z e d by a v o l a t i l e organic amine. A f t e r the i n i t i a l r e a c t i o n , a new hydroxyl group o r i g i n a t i n g from the epoxide i s formed. From t h i s new h y d r o x y l , a polymer begins to form. Due to the i o n i c nature of the r e a c t i o n and the a v a i l a b i l i t y of a l k o x y l ions i n the wood components, the chain length i s probably short due to c h a i n t r a n s f e r . Considering the a l k y l e n e oxides or epoxides i n l i g h t of the preceeding requirements, the lowest member i n the s e r i e s ( e t h y l ene oxide) i s a gas a t room temperature. Ethylene oxide

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

CELLULOSE TECHNOLOGY

120 Reagent

B o i l i n g point °C.

Ethylene oxide Propylene oxide Butylène oxide Epifluorohydrin Epichlorohydrin Epibromohydrin

RESEARCH

10.7 35 63 85 116 135

Trimethylamine Triethylamine

2.9 90

c a t a l y z e d with trimethylamin l o s e , but h i g h pressur or butylène oxide are l i q u i d temperatur c a t a l y z e d with t r i e t h y l a m i n e . Of the s u b s t i t u t e d halogen epoxides, e p i f l u o r o h y d r i n i s p r e f e r r e d but i t s cost p r o h i b i t s i t s use ($8/g). The b o i l i n g p o i n t of e p i c h l o r o h y d r i n i s higher but can be e a s i l y removed from the wood a f t e r r e a c t i o n . To determine i f the r e a c t i o n system was capable of s w e l l i n g the wood s t r u c t u r e , the s w e l l i n g c o e f f i c i e n t o f each separate r e agent was determined. A southern pine block (3/4" χ 3/4" χ 4") was immersed i n each separate reagent f o r 1 hour, 150 p s i at 120° C. The b l o c k volume was determined ovendry before treatment and wet immediately a f t e r treatment. The weight g a i n during E f f e c t o f Chemical Reagents on the Swelling of Wood, 120° C, 150 p s i , 1 Hr.

Reagent

Water T r i e thylamine Propylene oxide Epichlorohydrin

Swelling coefficient S 10 .7 5.6 5.8

Weight add-on % 0 .2 3.8 7.6

treatment i s the d i f f e r e n c e between ovendry weight before t r e a t ­ ment and ovendry again a f t e r treatment. I t might be expected that the a l k a l i n e amine would s w e l l the wood as does amines such as p y r i d i n e ; however, t r i e t h y l a m i n e does not s w e l l wood. The s w e l l i n g a b i l i t y of propylene oxide and e p i c h l o r o h y d r i n are about 60% that o f water. So i n the epoxide r e a c t i o n system, i t i s the epoxide that s w e l l s the wood s t r u c t u r e . The amount o f c a t a l y s t needed was determined by r e a c t i n g southern yellow pine with v a r y i n g r a t i o s of epoxide/amine. From t h i s data,

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

8.

ROWELL

Alkylene Oxide-Wood

R a t i o PO/TEA

Reactions

Wt.

20/80 50/50 80/20 90/10 95/5 97/3

121

% Add-On 20 44 52 53 50 40

a r a t i o of 95/5 epoxide to c a t a l y s t was chosen f o r maximum r e a c t i o n w i t h minimum reagent recovery. The c o n d i t i o n s of 120° C. at 150 p s i were chosen f o r a l l runs. By v a r y i n g the r e a c t i o n time, samples were prepared with polymer add-on l e v e l s of from 7 to 60% by weight. Changes i n Volum A f t e r Treatment

Compound

Propylene oxide Butylène oxide Propylene oxide Propylene oxide Epichlorohydrin

Green volume In. 3 3.48 3.60 3.66 3.60 3.60

with A l k y l e n e Oxides Ovendry volume before In. 3 3.24 3.24 3.42 3.30 3.36

Ovendry volume after In. 3 3.42 3.60 3.66 3.66 3.72

Weight add-on

% 15.9 21.1 26.1 34.1 41.0

At a weight percent add-on of approximately 20%, the volume of the t r e a t e d wood i s equal to the untreated green volume. Above about 30% weight add-on, the volume of the t r e a t e d wood i s l a r g e r than that of the green wood. These r e s u l t s show that the polymer i s l o c a t e d i n the c e l l w a l l . A d d i t i o n a l evidence o f t h i s i s shown i n the dimensional s t a b i l i t y ( a n t i s h r i n k e f f i c i e n c i e s ) of epoxide-treated wood. A n t i s h r i n k e f f i c i e n c i e s were determined by water soaking t r e a t e d and untreated samples f o r 7 days and measuring the change i n volume due to water a d s o r p t i o n . The h i g h e s t a n t i s h r i n k

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

122

CELLULOSE TECHNOLOGY RESEARCH

Antishrink

E f f i c i e n c y (R) of Southern Yellow Pine Blocks Weight add-on %

R

Propylene oxide

20.4 28.0 33.8 37.7 51.1

51.3 68.1 66.2 35.4 25.2

Epichlorohydrin

24.5

68.8

Compound

Butylène oxid e f f i c i e n c i e s (R) are i n the range of 21-28% weight add-on. Above t h i s l e v e l , the R values s t a r t to drop o f f which may mean the polymer loadings are so high they have broken the c e l l w a l l and a l l o w the wood to superswell above the green volume. In the e p i c h l o r o h y d r i n samples, the c h l o r i n e was confirmed to be i n the c e l l w a l l by energy d i s p e r s i v e a n a l y s i s of X-ray s p e c t r a generated i n the scanning e l e c t r o n microscope. The greatest percentage of c h l o r i n e was i n the S 2 l a y e r of the c e l l w a l l which i s the t h i c k e s t c e l l w a l l component and contains the most c e l l u l o s e . E l e c t r o n micrographs a l s o showed no polymer i n the lumen, but d i d show changes i n the nature of the c e l l w a l l . These f i n d i n g s of r e t e n t i o n of c h l o r i n e i n the r e a c t i o n of e p i c h l o r o h y d r i n under a l k a l i n e c o n d i t i o n s c o n t r a d i c t somewhat the l i t e r a t u r e on the mechanism of the r e a c t i o n . The r e a c t i o n as

R'0-CH -CH-CH -0R 2

2

OH

4

H0"

CH -CH-CH -OR+HCI 2

2

R'OH

shown i s reported to take place under s t r o n g l y a l k a l i n e condit i o n s (NaOH). The c h l o r o h y d r i n undergoing i n t e r n a l r e a c t i o n to give a new epoxide and HC1 s p l i t out. The new epoxide would then be a v a i l a b l e f o r c r o s s l i n k i n g . This r e a c t i o n does not take place when the r e a c t i o n i s c a t a l y z e d by t r i e t h y l a m i n e . There i s no l o s s of c h l o r i n e during the r e a c t i o n and, i f HCl was formed, there would be a drop i n the pH a f t e r r e a c t i o n . No pH drop was observed.

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

8.

ROW ELL

Alkylene Oxide-Wood

Reactions

123

The e f f e c t i v e n e s s of these epoxide treatments as decay r e tardants was determined by s o i l - b l o c k t e s t s using two brown-rot f u n g i . The brown r o t t i n g f u n g i are those which p r e f e r e n t i a l l y attack c e l l u l o s e i n the wood l e a v i n g the l i g n i n alone. Treated and untreated southern yellow pine blocks were placed i n t e s t with the fungus Lentinus lepideus and s e p a r a t e l y with L e n z i t e s trabea. Samples were removed at 6 and 12 weeks, and the extent of decay was determined by ovendry weight l o s s . The sample blocks from the r e d u c t i o n i n water s w e l l i n g t e s t (7 days leaching) were a l s o put i n t e s t to determine the changes i n decay r e s i s t a n c e as a f f e c t e d by l e a c h i n g . S o i l - B l o c k Tests on Propylene Oxide Treated Southern Yellow Pine Inoculate Percent weight add-on

0 5.1 24.0 36.6 44.5 50.9

Percent weight l o s s i n weeks (12) (6) 24.3 8.1 3.2 2.6 3.4 3.7

44.2 17.5 4.8 4.6 7.3 5.3

A weight l o s s a f t e r 12 weeks of l e s s than 5% i s regarded as a positive result. Propylene and butylène oxides and e p i c h l o r o h y d r i n a l l show good decay r e s i s t a n c e to Lentinus lepideus at l e v e l s of about 23% and above. For southern yellow pine, L e n z i t e s trabea i s a much more severe decay fungus.

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

CELLULOSE

124

TECHNOLOGY

RESEARCH

S o i l - B l o c k Tests on Treated Southern Yellow Pine Inoculated with Lerizites trabea Nonleached Sample

Leached

Percent weight l o s s a f t e r 6 weeks

12 weeks

6 weeks

12 weeks

Control

44.6

62.9

44.9

68.7

Propylene oxide, 20% 24 37 50

12.9 10.3 8.4 6.5

40.0 35.5 28.7 25.2

26.7 17.3 14.2 12.7

38.6 50.4 23.6 25.0

E p i c h l o r o h y d r i n , 17% 25 35 41

2.6 2.2

5.1 5.9

—

—

2.4 2.0 3.7

4.1 4.0

7.0 1.8 2.7

18.8 11.9 2.0

Butylène oxide,

7% 14 23

5.2 2.9 3.2

18.8 12.4 3.8

and the propylene oxide treatment does not hold up. For trabea, butylène oxide and e p i c h l o r o h y d r i n g i v e good decay r e s i s t a n c e a t l e v e l s above 22%. In c o n c l u s i o n , the data from t h i s work show that propylene oxide, butylène oxide, and e p i c h l o r o h y d r i n treatments g i v e good dimensional s t a b i l i t y to water s w e l l i n g at precent weight add-ons of approximately 25%. At these same l e v e l s of chemical s u b s t i t u t i o n , two of the treatments show good r o t r e s i s t a n c e . These treatments may f i n d a p p l i c a t i o n s i n products such as window u n i t s and millwork i n which r e s i s t a n c e to s w e l l i n g from water i s as important as r o t r e s i s t a n c e . Tests are now i n progress to determine s t r e n g t h l o s s , i f any, i n the treated wood as w e l l as s t u d i e s on weathering, g l u i n g , p a i n t a b i l i t y , and burning c h a r a c t e r i s t i c s .

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

9 Alkaline Degradation of a Nonreducing Cellulose. Model: 1,5-Anhydro-cellobiitol R A L P H E. B R A N D O N ,

LELAND

R. S C H R O E D E R ,

The Institute of Paper Chemistry, Appleton, Wis.

and D O N A L D C .

JOHNSON

54911

Abstract Degradations o f 1 , 5 - a n h y d r o - c e l l o b i i t o l at 160-180°C in oxygen-free, 0 . 5 - 2 . 5 N NaOH i n v o l v e cleavage o f both the g l y c o s y l ­ -oxygen bond (80-90%) and the oxygen-aglycon bond ( 1 0 - 2 0 % ) . Cleavage o f the oxygen-aglycon bond y i e l d s 1,5:3,6-dianhydro-D-galactitol (50-100%) and u n i d e n t i f i e d products (0-50%) from the a g l y con, and is b e l i e v e d t o occur by an S 1 mechanism. Cleavage o f the glycosyl-oxygen bond y i e l d s 1 , 5 - a n h y d r o - D - g l u c i t o l (100%) from the aglycon. The r e a c t i v e i n t e r m e d i a t e , 1,6-anhydro-β-D-glucopyranose, is formed from the g l y c o s y l moiety i n ca. 35% o f the cleavages o f the glycosyl-oxygen bond and, hence, its formation i s not as s i g n i f i c a n t as i s u s u a l l y presumed. Glycosyl-oxygen bond cleavage does not appear t o occur by a s i n g l e mechanism and i s probably governed by both S 1 c B (2') and SN1 mechanisms. In cont r a s t t o degradations o f 1 , 5 - a n h y d r o - c e l l o b i i t o l , degradations o f 1,5-anhydro-2,3,6-tri-O-methyl-cellobiitol form ca. 65% 1,6-anhydro-β-D-glucopyranose from glycosyl-oxygen bond cleavage. The i m p l i c a t i o n s o f these r e s u l t s with r e s p e c t t o a l k a l i n e cleavage of g l y c o s i d i c bonds i n c e l l u l o s e are d i s c u s s e d . N

N

Introduction High-temperature a l k a l i n e processes i n v o l v i n g c e l l u l o s i c m a t e r i a l s can r e s u l t i n a s i g n i f i c a n t l o s s o f weight and a d r a s t i c decrease i n the degree o f p o l y m e r i z a t i o n o f the c e l l u l o s e (1X3). The weight l o s s has been a t t r i b u t e d p r i m a r i l y t o endwise degradat i o n ("peeling") o f the p o l y s a c c h a r i d e w h i l e the d r a s t i c r e d u c t i o n i n the degree o f p o l y m e r i z a t i o n has been a t t r i b u t e d p r i m a r i l y t o random cleavage o f g l y c o s i d i c bonds (l). While anaerobic a l k a l i n e degradations o f a r y l g l y c o s i d e s j[) and a l k y l g l y c o s i d e s (£) have been i n v e s t i g a t e d e x t e n s i v e l y , and mechanisms have been proposed f o r these r e a c t i o n s , the mechanism o f a l k a l i n e cleavage o f g l y c o s i d i c l i n k a g e s j o i n i n g monosaccharide u n i t s i n o l i g o - o r p o l y s a c c h a r i d e s has r e c e i v e d l i t t l e 125

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

126

CELLULOSE TECHNOLOGY

RESEARCH

a t t e n t i o n . I t i s g e n e r a l l y assumed (2_, 3., 6) f o r c e l l u l o s e that a l k a l i n e cleavage o f the 3-1 ,U-glycosidic linkages occurs by a neighboring group mechanism i n which the aglycon i s d i s p l a c e d by the conjugate base o f the t r a n s - 2 - h y d r o x y l group. The mechanism i s analogous t o the mechanism proposed by McCloskey and Coleman (χ) t o account f o r the a l k a l i n e l a b i l i t y o f a r y l t r a n s - 1 , 2 - g l y c o pyranosides, and which has subsequently been e x t r a p o l a t e d , a l b e i t questionably (^), t o a l k y l glycopyranosides. Best and Green (8_) concluded that the data f o r the a l k a l i n e degradation o f methyl 3 - e e l l o b i o s i d e was c o n s i s t e n t with such a mechanism, and a more recent k i n e t i c a n a l y s i s o f these data by L a i (£) presumably strengthens t h i s c o n c l u s i o n . In t h i s paper we report t h e r e s u l t s o f a study o f the mecha­ nism o f degradation o f a nonreducing c e l l u l o s e model; 1,5-anhydroU-0-(3-D-glucopyranosyl)-D-glucitol 1,5 at l60-l80°C i n aqueous A u x i l i a r y studies o f degradations o f a p a r t i a l l y - m e t h y l a t e d de r i v a t i v e o f I_, 1,5-anhydro-4-O ( 3-D-glucopyranosyl )-2,3,6-tri-0_methyl-D-glucitol (1,5-anhydro-2,3,6-tri-O-methyl-cellobiitol) are a l s o reported. r

ι Results Product Analyses. The product d i s t r i b u t i o n f o r a l k a l i n e deg­ radations o f 1^ depended on the r e a c t i o n c o n d i t i o n s . S t a b l e , neu­ t r a l products i d e n t i f i e d were 1,5-anhydro-D-glucitol ( I I , 80-90$), l , 5 : 3 , 6 - d i a n h y d r o - D - g a l a c t i t o l ( I I I , 8-11$), 1,5-anhydro-D-gulitol (IV, v o l ) t o p r e c i p i ­ t a t e excess s i l v e r i o n , and analyzed by g . l . c . (Conditions B ) . A f t e r 5^· h r , the r e a c t i o n mixture was f i l t e r e d and the r e s i d u e was r i n s e d with CHC1 (100 ml). The combined f i l t r a t e s were washed with NaHCO (150 ml) and water (lOO ml), d r i e d ( C a C l ) , and evapo­ r a t e d , i n vacuo » t o a t h i c p y r i d i n e - a c e t i c anhydrid d i s a c c h a r i d e f r a c t i o n s on a s i l i c a g e l column (Grace Grade 950, 60-200 mesh, 275 g; 25 χ 1000 mm) e l u t e d with chloroform-ethyl acetate (2:1, v o l ) . The d i s a c c h a r i d e f r a c t i o n was deacetylated (30) and f r a c t i o n a t e d on a s i l i c a g e l column (lOO g, 25 χ 500 mm) with chlorοform-methanol (7:1, v o l ) t o g i v e V I I as the f i r s t d i ­ saccharide component e l u t e d . Since V I I could not be induced t o c r y s t a l l i z e , i t was d r i e d i n vacuo t o an amorphous s o l i d (32$ y i e l d ) , [a]§ 15-3° (H 0). (Found: C, 1+8.9; H, 7-6. Ci H Oio r e q u i r e s : C, 1+8.9; Η, 7-7$·) 3

3

2

5

2

5

2 8

A c i d h y d r o l y s i s o f VII gave V I I I and a,3-D-glucose as d e t e r ­ mined by g . l . c . (Conditions C) f o r the p e r - O - t r i m e t h y l s i l y l ethers.. The 3-configurâtion o f the g l y c o s i d i c l i n k a g e o f V I I was confirmed by a doublet ( H - l , δ 1+.1+5 ppm, Ji» » 7-0 Hz) i n i t s n.m.r. spec­ trum (D 0) which was c h a r a c t e r i s t i c o f an anomeric proton a s s o c i ­ ated with a β-D-glueopyranosidic bond (1+0) and s i m i l a r t o the H-1 doublet o f I_ (δ 1+.51 ppm, J i » 7.0 Hz). A c e t y l a t i o n o f V I I with a c e t i c anhydride-pyridine (38) gave l,5-anhydro-2 ,3 ,l+ , 6 ' - t e t r a - O - a c e t y l ^ ^ ^ - t r i - ^ - m e t h y l - c e l l o b i i t o l ; m.p. 80-80.5°C (from MeOH), [α]§* 15-7° (CHC1 ). MlU 18.6° ( C H C I 3 ) . (Found: C, 51-3; H, 6.8. C H 6 0 n , r e q u i r e s : C, f

j 2

2

F

f

s 2

!

!

!

3

23

3

51.5; H, 6.7$.) N-Butyl β-D-glucopyranoside (XXII). D e a c e t y l a t i o n (30) o f nb u t y l tetra-O-acetyl-3-D-glucopyranoside (hi) gave XXII; m.p. 6768°C ( f r o m E t O A c ) , [a]g° - 36.7° ( H 0 ) . L i t e r a t u r e : m.p. 66-67°C [ a ] - 37.1*° (H 0) (1+2). Cyclohexyl 3 - c e l l o b i o s i d e (XXIII). Reaction o f XIX with cyclohexanol (l+l) y i e l d e d c y c l o h e x y l 3 - c e l l o b i o s i d e heptaacetate (XXIV) (62$); m.p. 202-203.5°C (from EtOH), [a]§ - 25-7° (CHCI3)· (Found: C, 53-5; H, 6.5. C H 0 i 8 r e q u i r e s : C, 53-5; H, 6.5$·) Deacetylation (30) o f XXIV gave XXIII; m.p. 206.5-207-5°C (from EtOH), [α]§ - 26.3° (H 0). (Found: C, 51.2; H, 7-6. C i e H 0 i i r e q u i r e s : C, 50.9; H, 7.6$.) The n.m.r. spectrum (D 0) o f XXIII contained two anomeric proton doublets (δ 1+.53 Ppm> J 6.9 Hz and δ 1+.59 ppm, J 7.5 Hz), both c h a r a c t e r i s t i c o f 3-glucopyranosidic 2

D

5

2

5

3 2

l f 6

5

2

3 2

2

In Cellulose Technology Research; Turbak, A.; ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

144

CELLULOSE TECHNOLOGY RESEARCH

bonds, thus confirming the β-configuration o f the cyclohexoxy sub­ stituent. Product A n a l y s i s . The presence of I I , I I I , IV, V, and VI i n r e a c t i o n mixtures was demonstrated by g . l . c . a n a l y s i s o f the pert r i m e t h y l s i l y l ethers (Conditions D) and p.c. The a n a l y s i s and i d e n t i f i c a t i o n of I I I by g.l.c.-mass spectrometry i s described i n d e t a i l elsewhere (10). In a d d i t i o n , I I I was i s o l a t e d from a l a r g e - s c a l e degradation of I_ (ça. 8 g) i n 2.5N NaOH at 170°C (71-5 hr). The r e a c t i o n s o l u t i o n was deionized (Amberlite IR-120 and Amberlite MB-3) and concentrated i n vacuo. The a c e t y l a t e d mixture was separated i n t o crude mono- and d i s a c c h a r i d e f r a c t i o n s on a s i l i c a g e l column (Grace Grade 950, 60-200 mesh, 275 g; 25 x 1000 mm) using chloroform-ethyl acetate (2:1, v o l ) as the eluant. The t r a i l i n g monosaccharide f r a c t i o n s were deacetylated and separated on s i l i c a g e l (35 g> 1 v o l ) t o y i e l d t . l . c . pur v i r t u a l l y i d e n t i c a l with those of an authentic sample. The n.m.r. spectrum of the a c e t y l a t e d I I I was a l s o i d e n t i c a l with that o f known I I I d i a c e t a t e . K i n e t i c A n a l y s i s . A stock s o l u t i o n of 2.50N NaOH was p r e ­ pared under a n i t r o g e n atmosphere from carbon d i o x i d e - f r e e , t r i ­ p l y - d i s t i l l e d water (1+3). The other NaOH s o l u t i o n s were prepared from the stock s o l u t i o n u s i n g s i m i l a r water and, when a p p r o p r i a t e , NaOTs and Nal. A l l a l k a l i n e s o l u t i o n s were s t o r e d under n i t r o g e n in paraffin-lined bottles. The r e a c t o r system, described i n d e t a i l elsewhere (10), con­ s i s t e d of a type 316 s t a i n l e s s s t e e l r e a c t o r (100-ml c a p a c i t y ) from which samples (ca. 1 ml) could be withdrawn, and an o i l bath equipped with a Bronwell constant temperature c i r c u l a t o r which could maintain the bath w i t h i n 0.2°C o f the d e s i r e d temperature. Oxygen was desorbed from the r e a c t o r by heating the disassem­ b l e d r e a c t o r under vacuum (ça. 0.05 mm Hg, 1 0 5 - H 0 ° C , 2k-h& h r ) . The r e a c t o r was cooled under vacuum, and loaded (0.001 mole of r e actant; 100 ml of NaOH s o l u t i o n ) and assembled i n a n i t r o g e n atmosphere . The r e a c t o r was connected to the sampling system and immersed i n the o i l bath. The i n i t i a l sample f o r the a r b i t r a r y zero time was taken a f t e r the r e a c t o r had come t o the d e s i r e d temperature (