Research Of Special Amines Modified Polyvinyl Chloride

Polyvinyl chloride (PVC) is one of five major universal plastics; it is widely used in the varieties of fields. Because of the shortcomings such as poor thermal stability, creep resistance and brittleness at lower temperature, the application of PVC has been limited, so it is necessary to modify PVC.In this thesis, during the molding process, PVC was modified respectively by X amine and Y amine. The influence of the content of X amine and Y amine on tensile strength, impact strength, and rheological properties of PVC were investigated. The influence of amines on glass transition temperature of PVC was analyzed by DSC. The thermal stability of PVC before and after modification was analyzed by thermal stability analysis experiment at process temperature. The mechanism of modifiers on PVC was analyzed by infrared spectrum.The experiment results indicate that: the tensile strength of modified PVC increased at first and decreased later either modified by X amine or Y amine. The impact strength of modified PVC showed the trend of decrease; modified PVC was pseudoplastic fluid as before; both of the modified PVC and PVC have weaken phenomenon by shearing force, the fluidity of modified PVC decreased at first and increased afterwards along with increasing modifier. The glass transition temperature of modified PVC decreased along with increasing content of X amine and Y amine. Thermal stability analysis of modified PVC improved at conventional processing temperature. New characteristic absorption peaks were appeared in modified PVC material by infrared band analysis, by verified, it is the characteristic absorption peak of N+H2·Cl-. The infrared spectrum affirmed that two amine modifiers reacted with active chlorine atoms in PVC molecular chains; the amine salt was formation, and the HCl was separate out at the same time. These tests verified that X amine and Y amine were grafted onto PVC molecular chains by ionic bonds.