Studies On The Alkylation Reaction Of Chlorinated Polypropylene With Toluene

Friedel-Crafts alkylation reaction is an important reaction, widely used in organic and pharmaceutical synthesis. In recent years, alkylation reaction was applied to polymers. Alkylation reactions of polymers were conducted to modify their properties using polymers as alkylating agents, and good results were obtained. In this paper, alkylation reaction of chlorinated polypropylene (CPP) as alkylating agent with toluene was studied, and kinetic model was proposed. In this reaction, some of chlorine atoms were replaced by aromatic groups in order to change the molecular structure and reduce the polarity of CPP, and further to improve the miscibility of CPP and resins and enlarge its application.To begin with, a more accurate and suitable method to determine chlorine content was proposed and called oxygen combustion-potentiometric titration method. It made two improvements based on the oxygen combustion method. One was that, potentiometric titration was used to replace indicator to show the end-point. The other was data processing. The titration curve was fit and an equation was obtained using Origin software. Chlorine content could be calculated from the parameter of the equation, and was more accurate. The method was used for future kinetic study.Dilution ratio was the volume ratio of good solvent to the maximal amount of non-solvent that could be added to good solvent. In this study, the effects of concentration, temperature and chlorine content on dilution ratio were investigated. It was found that dilution ratio was increasing with the reducing concentration, rising temperature and decreasing chlorine content.Then, the alkylation reaction of CPP as alkylating agent with toluene catalyzed by aluminum chloride (AlCl₃) was investigated in details. The results of orthogonal test showed that, the amount of AlCl₃ exerted the strongest influence on the reaction, following was the temperature and the concentration of CPP-toluene solution, and reaction time was the least. In the conditional experiments, it was found that, the chlorine content was decreasing with the increasing amount of AlCl₃, rising temperature and reducing concentration. In the following, a series of kinetic data were...