Research Of Polyvinyl Chloride Modified By Hexamethylene Tetramine,Nylon 6 Oligomer,X Amine

Polyvinyl chloride (PVC) which is one of the five major universal plastics originates from calcium carbide method in our country. The price of PVC is less affected by petroleum's, so modification of PVC becomes research hotspots in recent years.In this thesis, PVC was respectively modified with three different amine modifiers hexamethylene tetramine,Nylon 6 oligomer,X amine by melting blending techniques. The effect of the addition of hexamethylene tetramine,Nylon 6 oligomer,X amine on the tensile strengths and rheological properties of modified PVC was studied, the thermal stability of PVC materials before and after modification were analyzed by thermogravimetry and thermal stability analysis experiment at conventional processing temperature, the mechanism between modifiers and PVC was analyzed by research of experiment analysis and infrared spectrum.The experimental results indicate that: the rheological properties of PVC after modification are almost invariant and still pseudo-plastic fluid. The tensile strengths of PVC materials modified with hexamethylene tetramine,Nylon 6 oligomer improve while the fluidity reduce; as the addition of X amine increase, the tensile strengths of PVC materials modified with X amine increased first and decrease afterwards. When the addition of X amine is less, the macromolecule of PVC grafted with X amine have no self-plasticization, but while the addition reach a certain level, the macromolecule become self-plasticization which decrease the intermolecular force and macromolecular entanglements. Thermogravimetric curves of materials before and after modification have no difference below decomposition temperature of materials, the thermogravimetric curves above decomposition temperature show that thermal stability of PVC materials after modification with hexamethylene tetramine,Nylon 6 oligomer,X amine decrease. At conventional processing temperature thermal stability analysis include that the thermal stability of PVC materials modified with hexamethylene tetramine,Nylon 6 oligomer,X amine improve, the processing temperature of PVC is usually below decomposition temperature, so the conclusion that is obtained by thermal stability analysis at conventional processing temperature have more practical significance. By research of experiment and infrared spectrum three amine modifiers may react with active chlorine atoms in PVC molecular chains. The reaction mode between three amine modifiers and PVC is deduced, that is, ion-type crosslinked structure is formed by PVC reaction with hexamethylene tetramine,Nylon 6 oligomer while X amine is grafted onto PVC molecular chains by ionic bonds.