Studies On The Improvement Of Chlorinated Polypropylene With Toluene

Worked as an adhesion promoter, chlorinated polypropylene (CPP for short)improves the adhesive power of many dopes to polypropylene substrates, so it waswidely used in our daily life. At present, the CPP which mass-produced in our countrywas used as color carrier of printing ink and its chloride content was 30%. When CPP wasused as dope, it needs lower chloride content, lower molecular weight and often dissolves intoluene solvent. In our laboratory, Liumin discovered that put AlCl₃ as a catalyst intothis toluene solution, depending on the mechanism of Friedel-Crafts alkylationreaction, could reduce the chloride content to fit the using as dope. During this process, themolecular weight decreased and made a large progress in her work. In her method, she needs toenter active carbon into production solution to take off catalyst and purify our production. It's notonly inconvenience but also active carbon might adsorb great molecular. We couldn't getsatisfactory adhesive power until put large number of improved CPP into resin. All my workswere based on Liumin's work and got many fruits just as follows: using FeCl₃ instead of AlCl₃as the catalyst, taking the mixture of acetone and methanol replace active carbon to purify theproduction, after these improvements the capabilities of production were improved. Adding 5% ofmy production into SZ-97 oil, the mixture could fit the request of adhesive power andit's hopeful for this company to alter the actuality of importing overseas CPP.To begin with, there were many methods to measure the minimum chloride contentof a compound. I compared chloride ion additive selective electrode method, ionchromatography method, acid-base electric titration method with acid-base titration method todetermine the chloride content of CPP and PVC. The results showed that the ion chromatographymethod and acid-base electric titration method have higher precision while acid-base titrationmethod was a bit worse than them and chloride ion additive selective electrode method toke theworst precision. After thinking over the maneuverability of experiments and the credibility ofresults, I selected acid-base titration method to measure the chloride content of polymers andcompared the results with the data which the producing company had given. The data showed thatwe could gain credible results with acid-base titration method and this will be a base of thefollowing works.Then, the alkylation reaction of CPP as alkylating agent reacts with toluenewhich catalyzed by FeCl₃,ZnCl₂,SnCl₂·2H₂O or H₃PO₄ were examined and compared.The phenomenon of these experiments showed that FeCl₃ could successfully carry outthe alkylation reaction. The spectroscopy of IR indicated that the aromatic group wasgrafted onto the molecular chain of CPP successfully. Through determining themolecular weight we know that part of the production have higher molecular weight than rawmaterial CPP, this make a possibility of weaken the sharp rupture of molecular chain.Had been contrasted the spectroscopy of GPC gotten from different conditions, wehad an elementary cognition of the reaction mechanism and it would provide areference for my next work.Next, taken an orthogonal test and studied the effect of reaction time, reactiontemperate, dosage of catalyst, the concentration of CPP-toluene solution and the water containing in system to the chloride content of production. The results showed that dosageof catalyst give the most notable effect to this reaction. We also investigated theinfluence of dosage of catalyst to reaction progress, dilution ratio and adhesive power,studied the influence of reaction time to reaction progress, proposed this alkylationreaction kinetics model was (?)=0.016×(1-x)^10.06 and gained the best reactioncondition was putting material in the mass rate of toluene: CPP: FeCl₃=4: 1: 0.15.After fractionating my production and determining the chloride content of the fractions,we gained that there was no distributing of chloride content in my productions.At last, we measured the miscibility and adhesive power of improved CPP andalkyd, elicited that the production's adhesive capability was much better than rawmaterial CPP.