Enzyme-catalyzed transesterification of vinyl esters on cellulose solids

Authors
Citation
Jb. Xie et Yl. Hsieh, Enzyme-catalyzed transesterification of vinyl esters on cellulose solids, J POL SC PC, 39(11), 2001, pp. 1931-1939
Citations number
28
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
ISSN journal
0887624X → ACNP
Volume
39
Issue
11
Year of publication
2001
Pages
1931 - 1939
Database
ISI
SICI code
0887-624X(20010601)39:11<1931:ETOVEO>2.0.ZU;2-F
Abstract
Enzyme-catalyzed transesterification of several cellulose solids in organic media have been investigated. Several protease enzymes were made soluble i n organic media through ion-paired enzyme-surfactant complexes. Subtilisin Carsberg was found to be catalytically active in the transesterification of cellulose with vinyl propionate and vinyl acrylate in anhydrous pyridine. The ester carbonyl groups in acylated cellulose derivatives were confirmed by Fourier transform infrared spectroscopy. The surfaces of these cellulose derivatives became hydrophobic as demonstrated by increased water-contact angles. The enzyme-catalyzed transesterification was confirmed to regiosele ctively target the primary hydroxyl group of cellulose by reactions on spec ifically substituted cellulose. The cellulose esters from enzyme-catalyzed transesterification could be hydrolyzed partially by the same enzyme in aqu eous media, and were thus biodegradable. Surface grafting of cellulose acry late was demonstrated using azobisisobutylonitrile-initiated polymerization of acrylonitrile in dimethylformamide. Polyacryonitrile (PAN)-g-cellulose shows a differ ent thermal behavior from cellulose, homopolymer PAN, and PA N/cellulose blends. The grafted PAN on PAN-g-cellulose at a 16% grafting ad d-on is incapable of cyclization. (C) 2001 John Wiley & Inc, Inc.