The Syntesis Of Modified CPE By Chlorinating-grafting Of PE In Situ

In this thesis, the chlorinating-grafting reaction of polyethylene (PE) in-situ withmethyl methacrylate (MMA), acrylonitrile (AN), styrene (St), 2-hydroxy ethylacrylate (HEA) and maleic anhydride (MAH) were discussed. The solid-phaseprocess of chlorination was adopted using PE powder and the monomers which canpolymerize through radical process as starting materials. There was no other reactingmedium. The effects of the reaction conditions, such as chlorine content, temperatureand amount of monomers added, on the properties of CPE chlorinating-graftingmodified were investigated. The structure of grafting product of CPE-cg-MAH wasdetermined by Infrared spectrum technique. It has been found that the monomer ofMA could be grafted to PE backbone and obtained modified CPE. The copolymersof CPE-cg-PMMA, CPE-cg-PAN, CPE-cg-PSt and CPE-cg-PHEA were synthesizedand the mechanical properties of these copolymers were also determined. In thecomparison to the unmodified CPE, in which the strength is 6～9 MPa and theelongation at break is 1557%, CPE-cg-PAN has 12MPa of strength and 964 ofelongation at break. CPE-cg-PSt has 12MPa of strength and 1293 of elongation atbreak. The glass transition temperature and molten temperature of CPE-cg-PMMAwere examined and the effects of chlorine content, chlorinating temperature, theamount of MMA added and the amount of initiator used to mechanical performances of CPE-cg-PMMA were studied. The results demonstrated that the method ofchlorinating grafting in situ can simplify the process of the modification of PE and itwill be an effective method to introduce groups of -OH, -NH, COOH, -CN to PEbackbone.