| As an adhesion promoter, the chlorinated polypropylene(CPP) is used in the coated process for polypropylene products. Therefore, to study the compatibility of CPP with other coating resins is an important foundation work. In this paper, the compatibility of CPP with alkyd and improved methods of the their compatibility are as focal points to be studied. The work is divided into two parts. In the first part compatibility vary with the hydroxyl value of alkyd resin is investigated. In the second part, synthesis method of maleic anhydride grafted chlorinated polypropylene and compatibility vary with the graft ratio are investigated. Chlorinated polypropylene(containing about 30% chlorine by weight) used in this paper is product from Guangzhou Jinzhujiang, it is yellowish and translucence.Alkyd resins with different hydroxyl content were synthesized by alcoholysis method. Compatibility of chlorinated polypropylene and alkyd resin was investigated in the solution of 70% xylene. In the solution, different weight ratio of chlorinated polypropylene to alkyd resin was in a range of 10/1-1/10. The experimental results show that the solution has a uniform phase when chlorinated polypropylene/alkyd resin: 10/1, 5/1, 2/1, and blurred lamination when chlorinated polypropylene/alkyd resin=l/10. When the ratio of chlorinated polypropylene to alkyd resin is 1/1-1/4.4, the solution is lamination. The transparency of the film of the binary system (chlorinated polypropylene and alkyd resin) was characterized by glossiness after the solvent volatilizing. It was observed when the weight ratio was not less than 2/1, the film was transparent, and when the weight ratio =1/4.4, the transparency was the worst, and when the weight ratio =1/10, the transparency of the film was improved. In lamination region, the volume ratio of the two layers is related to the hydroxyl content of alkyd resin. With the hydroxyl content of alkyd resin decreasing, components in the two layers gradually approach. When the hydroxyl content=0, lamination was not observed and the solution become uniform. Thus, compatibility of chlorinated polypropylene and alkyd resin are related to the weight ratio of CPP to alkyd resin and the hydroxyl content of alkyd resin.Synthesis of maleic anhydride grafted chlorinated polypropylene was studied, and it is proved that maleic anhydride was grafted to chlorinated polypropylene according to IR spectrum, On the base, orthogonal test Lg (34) was done in order to investigate the effect of different factors on the graft yield. In this orthogonal test,amount of initiator BPO, amount of MAH (maleic anhydride) , reaction temperature and time were investigated. The result showed that the effect of the amount of BPO was maximum and the effect of time was the least. Then several groups of qualification tests were researched. It was found that grafting yield increased with increasing the amount of BPO and then the grafting yield became constant when BPO/CPP 0.15. With the amount of MAH increasing, the grafting yield grew quickly in the beginning, and the grafting yield was almost constant when MAH/CPP was in a range of 0.48-0.98. With reaction temperature increasing, the grafting yield increased clearly, but when reaction temperature was more than 100 , the grafting yield decreased. When reaction time was prolonged, the grafting yield was increasing quickly in the beginning of reaction, at last the grafting yield became constant. In reaction process, graft and homopolymerizing reaction of MAH are in existence simultaneously.Molecular construction was estimated by determining MAH and Cl content. Construction unit number was calculated by determining molecular weight. About 30-67 MAH units are grafted to a CPP chain. In graft reaction, there is cross linking reaction, but the cross linkage is not serious.Compatibility of maleic anhydride grafted chlorinated polypropylene and alkyd resin was investigated. It shows that compatibility of chlorinated polypropylene with alkyd resin improves remarkably with the grafting rati...
|
PDF Full Text Request