A new method for preparation of polystyrene nanoparticles by using a method of RAFT living polymerization was studied.Firstly,small molecular reversible addition⁃fragmentation chain transfer agent,three thiocarbonate (DBTTC),was synthesized for active polymerization.Then the emulsifier free emulsion polymerization method was used to prepare styrene polystyrene latex with narrow particle size distribution using itaconic acid as the monomer and ammonium persulfate as initiator.Effects of the molar ratio of St/IA,molar ratio of acetone/water,reaction temperature and amount of DBTTC on the latex particle size were studied respectively.The latices were characterized by Malvern nanosizer,TEM,GPC,surface tension and conductometric titration.The results show that when the temperature is 78 ℃,the molar ratio of St/IA is 10,and the molar ratio of DBTTC/St is 0.064,the molar ratio of acetone/water is 4∶6,the polystyrene nanometer latex particles with average particle size of 98 nm can be obtained.

Phthalate-based plasticizers are the most added additives in polyvinyl chloride, however, it was found that the monomer-type plasticizer had poor migration resistance and potential carcinogenicity, which seriously affected the application performance and service life of the product. Polypropylene glycol adipate (PPA), epoxy soybean oil (ESO) and dioctyl phthalate (DOP) were compounded in this paper. The mechanical properties, plasticizing efficiency, thermal properties and durability of the plasticizer were investigated. The results show that the plasticizing efficiency of 40DOP/10PPA and 40DOP/10ESO is better than 110%, the performance of anti-extraction and anti-volatilization is much better than DOP, which can greatly reduce the glass transition temperature of PVC and improve its processing performance of PVC.

Polyvinyl chloride (PVC) is generally used for phthalate plasticizers, because of its high plasticizing efficiency. These phthalate plasticizers will cause the problems of durability, toxicity and potential carcinogenicity, they can make service life shorter, endanger human and animal health. So it has been gradually replaced by the new type of plasticizer. Polyester plasticizer is a kind of green environmental protection plasticizer and can better solve the disadvantage of traditional plasticizer, so it was widely studied at home and abroad. In this article, plasticizing mechanism(Lubricity theory, Gel theory, Free volume theory), selection criteria, synthesis and classification of the polyester plasticizer are introduced. The polyester plasticizer is mainly divided into two categories:biological polyester plasticizer and petroleum polyester plasticizer.

With itaconic acid (IA) and 1,4  butanediol (BDO) as the raw materials, the resultant hydroxyl terminated aliphatic unsaturated polyesters (PBI) were prepared. The unsaturated polyurethane was prepared with PBI as the soft segment and toluene diisocynate (T DI) as the hard segment. The effect of its reaction conditions on the mechanical properties of the unsaturated polyurethane was also investigated. It was found that the film products with the optimum properties were obtained under the material mass ratio o f TDI and PBI 1 ∶ 1.5, the reaction temperature 80 ℃ , optimum reaction time 2 h, with dibutyltin dilaurate in an amount of 1% as the catalyst. Combining with benzoyl peroxide in an amount of 1%,as an initiator, the film of the unsaturated polyurethane was smooth, transparent and level. The hardness was 6H, and the adhesion property was A grade.

A series of copolyesterspoly(butylene terephthalatecobutylene itaconate) (PBTI) were synthesized by melt polycondensation from dimethyl itaconate(DI), 1,4butanediol(BD) and dimethyl terephthalate (DMT). On this basis, hydrophilic diol( PEG) was selected as comonomer component to react with DI，DMI and BD via direct melt polycondensation. A series of degradable aliphaticaromatic copolyesters (PBTIG) with different PEG molecular weight and content were synthesized. Hydrolytic degradation results demonstrated that with the increase of the itaconic acid content, the degradation rate was speeded up, andthe hydrophilic PEG significantly increased the degradation rate of the copolyesters. The hydrolysis experiments showed that after 160 h, the residual of the PBTI was 91.35%, while, the residual amount is only 81.20% after adding hydrophilic PEG. The degradation rate was increased by 117.34% than PBTI.