Cationic graft copolymerization of tetrahydrofuran onto bromodeoxycellulose

Abstract

SYNOPSISCationic graft copolymerization of tetrahydrofuran onto halodeoxycelluloses, which were prepared under homogeneous conditions, was studied with silver tetrafluoroborate as a n initiator. 6-Bromo-6-deoxycelluloses gave graft copolymers, insoluble but swollen in tetrahydrofuran, whereas chlorodeoxycelluloses gave no graft copolymer. The graft copolymers were hydrolyzed in 2N HCl to give hydrolyzate solutions and insoluble solids. The hydrolyzate was found to be composed of 6-0-(4-hydroxybutyl) glucose and 6-0-(9-hydroxy-5-oxanonyl) glucose as well as oligomers of tetrahydrofuran by gas chromatography and gas chromatography-mass spectrometry after trifluoroacetylation. The insoluble solid was cross-linked polyoxytetramethylene, which could be hydrolyzed only very slowly in 2N HCl to yield oligomers of tetrahydrofuran. Thermal behavior of the graft copolymer was compared with t h a t of cellulose and of homopolymer of tetrahydrofuran. 0 1994

New photoantimicrobial films composed of porphyrinated lipophilic cellulose esters

“…A limpid solution was obtained after cooling down to room temperature and overnight stirring. [18][19][20] The first step involves the esterification of cellulose by the system PpIX/TsCl/pyridine (Scheme 1). Equimolecular concentrations of TsCl, protoporphyrin IX, and pyridine were added with stirring at 80°C; the three products remain soluble throughout the process, then the mixture was left for 24 h. The plastic porphyrin content was monitored by the amount of PpIX added.…”

Deoxycelluloses and related structures

“…Methyl methacrylate was readily grafted on chlorodeoxycellulose at 60°C with a conventional free radical initiator [25]. Tetrahydrofuran (THF) was cationically grafted onto bromodeoxycellulose using AgBF 4 as the initiator; chlorodeoxycelluloses could not be grafted with THF under these conditions [26].…”

Uncatalyzed photografting of polyacrylamide from functionalized cellulosic and lignocellulosic materials

“…by thermal and/or photochemical processes 9,11 by using water soluble/insoluble initiators. 8,11,12 Again, functionalization of existing polymeric backbones prior to graft copolymerization, aiming at successful modification of the former, is also a well-established technique. 13 In each case, some of the physical, chemical, and textile-related properties, like crystallinity, 7 tensile strength, dyeability, 10 ion exchange properties, 3,14 etc., are found to be significantly modified.…”