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ABSTRACT:To modify cellulose powder surface, the grafting of polymers with controlled molecular weight and narrow molecular weight distribution onto the surface by the termination of living polymer cation with amino groups introduced onto cellulose powder surface was investigated. The introduction of amino groups onto cellulose powder surface was achieved by the treatment of cellulose powder with isatoic anhydride. It was found that cellulose powder having amino groups are readily reacted with living poly(2-methyl-2-oxazoline) (polyMeOZO) cation, which was generated by ringopening polymerization with methyl p-toluenesulfonate as an initiator, and polyMeOZO with controlled molecular weight and narrow molecular weight distribution was grafted onto the surface. By the termination of living poly(isobutyl vinyl ether) (polyIBVE), which was generated by the polymerization with HCl/ZnCl 2 initiating system, with amino groups on cellulose powder, polyIBVE was also grafted onto the surface. The mole number of grafted polymer chain on cellulose powder surfaces decreased with increasing molecular weight of the living polymer cation, because of increasing steric hindrance with increasing molecular weight of living polymer cation. Wettability of cellulose powder surface to water was found to be controlled by grafting of hydrophilic or hydrophobic polymer onto the surface.

ABSTRACT:The grafting of polymers having controlled molecular weight and narrow molecular weight distribution onto chitosan powder by the termination of living polymer cation with amino groups on chitosan powder was investigated in heterogeneous system. The amino groups of chitosan powder successfully reacted with living poly(isobutyl vinyl ether) [poly(IBVE)] and poly(2-methyl-2-oxazoline) [poly(MeOZO)] cation with controlled molecular weight and narrow molecular weight distribution to give the corresponding polymer-grafted chitosan powders. The percentage of poly(MeOZO) grafting gradually increased and reached 24.5% after 4 days. The solubility of poly(MeOZO)-grafted chitosan in water increased with an increase in the amount of grafted polymer. It was suggested that grafting reaction of living polymer cation with chitosan powder proceeds from surface amino groups to inner amino groups of the powder with progress of the reaction. The mole number of grafted polymer chain on chitosan powder decreased with an increase in the molecular weight of the living polymer cation because the steric hindrance of functional groups of chitosan powder increased with the increasing molecular weight of living polymer.

This article deals with the synthesis of plant oil-based shape memory materials from epoxidized soybean oil (ESO) and polycaprolactone (PCL). PolyESO/PCLs were synthesized by an acid-catalyzed curing in the presence of PCL. During the reaction, PCL scarcely reacted with ESO and the crystallinity of the PCL component decreased to form a semi-interpenetrating network structure. The incorporation of the PCL components improved the maximum stress and strain at break of ESO-based network polymer. The polyESO/PCL was gradually degraded by Pseudomonas cepasia lipase. Furthermore, the polyESO/PCLs exhibited excellent shape memory properties, and the strain fixity depended on the feed ratio of ESO and PCL. The shape memory-recovery behaviors were repeatedly practicable. The resulting materials are expected to contribute to the development of biodegradable intelligent materials.