Efficient Graft Copolymerization of 2-Methyl-2-oxazoline onto Tosyl- and Iodo-Chitins in Solution

Abstract

ABSTRACT:Graft copolymerization of 2-methyl-2-oxazoline onto tosyl-and iodo-chitins has been examined. The reaction proceeded efficiently with tosyl-chitin in solution to give chitin derivatives having poly(N-acetylethyleneimine) side chains, and the grafting percentage was 280% under appropriate conditions. Graft copolymerization was also possible with iodo-chitin, but rather sluggish. Hydrolytic degradation of the chitin main chain allowed the isolation of the introduced side chains. The number-average molecular weight of the polyethyleneimine isolated from a graft copolymer with grafting percentage of 160% was 2700, indicating that 18% of the carbon atoms having a tosyloxy group were actually utilized for initiating the graft copolymerization. The resulting graft copolymers showed high affinity for both organic solvents and water, and may be useful as a new type of chitin-derived hybrid materials.

Hydrogels based on modified chitosan, 1. Synthesis and swelling behavior of poly(acrylic acid) grafted chitosan

“…This is due to the fact that the method used to calculate the %E is based on weight difference between the initial weight of dry chitosan and that of the grafted product and bonded water being difficult to remove. Although the %E of 59% is rather high, it is in the same range as values found by Kurita et al 43) on grafting polystyrene onto mercaptochitin. The decrease in %E observed for longer reaction times cannot be explained at this stage.…”

Selective Modification of Chitin and Chitosan: En Route to Tailored Oligosaccharides

“…The preparation of tosyl derivatives comprises the reaction of chitosan or chitin with tosyl chloride in pyridine or in a DMAc ( N , N ‐dimethylacetamide)/LiCl solution . The recently described methods for chitin tosylation are an alternative to that described by Kurita et al., where deacetylation was observed . Several nucleophiles such as sodium iodide, sodium azide, or potassium thioacetate were used to replace the tosyl group to produce iodo‐, azido‐, or mercapto‐chitin and chitosan derivatives, respectively.…”

“…The recently described methods for chitin tosylation are an alternative to that described by Kurita et al., where deacetylation was observed . Several nucleophiles such as sodium iodide, sodium azide, or potassium thioacetate were used to replace the tosyl group to produce iodo‐, azido‐, or mercapto‐chitin and chitosan derivatives, respectively. In fact, this methodology can be applied to produce relevant materials, such as a chitosan derivative possessing a cyclodextrin at O‐6, which was obtained by nucleophilic substitution of the tosyl group by an ethylenediamine‐substituted cyclodextrin.…”

Grafting reaction of living polymer cations with amino groups on chitosan powder

“…in solution, 2 graft copolymerization of methyl cation. The preparation of chitosan powder was achieved by reprecipitation by adding alkali solumethacrylate onto mercapto-chitin, 3 and the development of polyurethane-chitin powder comtion into HCl solution of chitosan.…”