Papers by Author: You Ping Wu

Abstract: Novel biocompatible tough hydrogels were prepared through free radical micellar polymerization of N-isopropylacrylamide (NIPAM) with ammonium persulphate (APS) as initiator, in which hydrophobic monomer stearyl acrylate (C18) underwent micellar polymerization in the presence of gelatin as emulsifier. FT-IR and DSC demonstrated the formation of co-polymer of NIPAM and C18. Swelling results indicated that hydrophobic polymer domains derived from C18 in aqueous medium acted as the physical crosslinking points by hydrophobic association. Uniaxial tensile test demonstrated the mechanical properties of hydrogels increased with increasing C18 and gelatin contents. The hydrogel exhibited low toxicity and promoted cell proliferation. The desirable toughness, low toxicity and the promoting effect of cell proliferation made the present hydrogels good candidates for tissue regeneration materials.

Abstract: Since rubber was applied in people’s normal life, researchers have started to exploit the rubber reinforcing techniques and the relative mechanism. Developing high-effective, simple and economical reinforcing methods and fillers are the emphasis of rubber industry, technology and science. In this paper a rubber ideal filler (IF) is shown. This IF is a kind of composite with core-shell structure which was synthesized by seeded emulsion polymerization. It used styrene (St), polybutadiene oligomer (PBD) as monomers and divinyl benzene (DVB) as cross-linking agent. The effect of the amount of cross-linking agent, concentration of emulsifier and initiator on the stability of the emulsion was studied. The morphology of the latex particles with core-shell structure was characterized by high resolution SEM (ESEM) and DSC (Tg). The results showed that cross-linking polymeric particles exhibited strong reinforcing effect on styrene-butadiene rubber (SBR).