Lactide一glycolide copolymerization with stannous octanoate as an initiator and dedecanolas regulator was carried out.The effect of reaction condition such as reaction time,temperature, initiatorconcentration, regulator and monomer ratbonpolymerization conversion,molecular weight and its distrbu-tion were investigated.The obtained results show that the finest reaction condition are initiator 0. 075%,ternperature 170℃ and reaction time 6hr.At this reaction condition,both molecular weight and polymer-ization conversion obtained are vecy high.

利用导管连接神经断端以实现修复周围神经缺损是目前研究较为活跃的课题。本文主要从生物医用材料研究与应用的角度对近年来的进展进行综述。表明此项研究已由单纯使用导管向利用组织工程原理、综合使用导管及其它方法以更好修复损伤的方向发展。

In the paper,in vitro degradation of DL polylactic acid (PDLLA) film was studied.Regulation and tendency of degradation were showed by molecular weight regulator and monomer ration mass lossing.Degradation mechanism was discussed in light.It was thought that degradation of PDLLA in vitro was a simple hydrolysis reaction.The hydrolysis reaction was self catalytic reaction caused by terminal carboxyl group.

ObjectiveTo prepare artificial viscoelastic agent used in ophthalmic operation as a substitute of Healon. MethodsPolyacrylamide was synthesized in aqueous solution of acrylamide. Residual monomer(Am) was separated from polymer by a novel method, extraction by semi permeable film. Results and ConclusionsArtificial viscoelastic agent prepared has advantages on cost of manufacture, processing repeatability and stability of storage comparing to Healon.

ObjectiveTo approach the taxonomy of polymer hydrogels prepared with composite material science methods.MethodsThe research results which have been obtained were synthesized and analysed in the light of multiscale design viewpoint,and the hydrogel composite materials were classified by the composite ways and its structural levels.Results and ConclusionA kind of taxonomy system was advanced in which new concepts of intermolecular composite,textural composite etc.were induced.Apply-ing these concepts and methods will be helpful to research on composite biomaterials.

A new kind of medical sponges,ionic polyvinyl alcohol sponges(i-PVA sponges)were prepared by surface-grafting of acrylic acid onto acetal-PVA sponges.i-PVA sponges obtained show excellent hydrophilicity and water-absorption.The i-PVA sponges are three dimentional porous network.Because there are great amount of carboxyl and sodium carboxylate groups on PVA molecule chains,the speed of water absorption and water-absorptivity is >2.9mm/s and >15 times respectively.That is,in the case of the cataract-extraction,the polyion-modified sponges much more advantageous than any traditional nonionic polymer sponges.

ObjectivePolyamidoamine(PAMAM) dendrimers enhance the solubility of nicotinic acid. MethodsPAMAM dendrimers of generation 1 to 6 were prepared and the effect of pH and concentration of the dendrimers on the solubility enhancement of nicotinic acid was investigated. ResultsThe pH and concentration of the dendrimers influence the solubility enhancement of nicotinic acid. Conclusions Electrostatic interaction between the carboxyl group of the nicotinic acid and the amine groups of the dendrimers is involved.