Synthesis, Characterization And Performance Of Low Molecular Weight CPP And Its Grafting Copolymerization

In this paper CPP is prepared by gas-solid phase based on PP which the degree ofcrystallinity is32%and the molecular weight is low, as well as many kind of graftedpolymers by in situ chlorinating-graft copolymerization(ISCGC) with Methylmethacrylate (MMA), ethyl acrylate (EA), alpha methyl acrylic acid, maleic anhydride(MAH) or glycidyl methacrylate (GMA) as grafting monomers. The target is to obtainCPP as coating with excellent paint film performance.The aim of this paper is to obtain CPP with high chlorine content and goodsolubility, and explore the main paint film performance of product as coating. Thefactors affecting chlorination degree and chlorination uniformity of product areexplored in the first, due to study the particle size and distribution and the residualcrystallization of polymer, the condition of obtaining high chlorine content CPP isgained, and the effect of chlorine content on solubility and crystallinity is discussed.Meanwhile, the molecular structure of product is characterized by FTIR and1H-NMR,the results show that all of the three kinds of hydrogen(CH3,CH2，CH) in PPchain can be replaced by chlorine, but the tertiary hydrogen is more probablysubstituted with the increasing of the polymer’s chlorine content. During chlorinatedreaction there is a phenomenon of removing HCl from the main chain, which can beeffectively suppressed by ISCGC. In addition, GPC shows that there is weakβ-degradation during chlorinated reaction, ISCGC can effectively suppressβ-degradation and there is no crosslink between polymers which can also be indicatedby Gel content test. The reaction mechanism is inferred based on analyzing of thestructure.Finally, the adhesion of product is tested and the results show that the adhesion ofCPP is bad which can not meet the requirement as coating, but the adhesion of polymercan be improved by ISCGC. Due to study the effect of different monomers onsolubility and adhesion of grafted polymer to choose grafting system which producthas the best adhesion, that is GMA and MAH. And the effect of monomer amount andratio on adhesion of polymer is also explored.