Preparation And Properties Of Vinyl-Based Thermoplastic Elastomer

In this dissertation, two methods were used to prepare PVC-based thermoplastic elastomer (PVC-TPE). Firstly, PVC-TPE was prepared by in-situ melt blending with acrylate monomers, PVC resin (PVC-1300, PVC-2500), plasticizer and modifier. Secondly, DPVC-TPE was prepared by in-situ graft copolymerization with DPVC and acrylic monomers,The DPVC was prepared by removing a small amount of HCl of PVC-1300 resin in solution of NaOH. Mechanical properties, dynamic mechanical properties, heat resistance and rheological properties of processed of PVC-TPE or DPVC-TPE were studied by universal tensile testing machine, dynamic mechanical analyzer, thermal analyzer and torque rheometer.In the first approach, the effect of plasticizer dosage, the type of acrylate monomer and dosage, in-situ melt blending processing technology on mechanical properties and processing performance of PVC-TPE were studied.The results showed that, the effect of amount of DOP was pivotal on mechanical properties and processing performance of PVC-TPE. With the amount of DOP increased, the elasticity of TPE was enhanced, the hardness and the compression permanent deformation rate were decreased, and the plasticization became easily. The DMA experimental results showed that, the Tg of PVC-TPE shifte to the low temperature region with the increasing of DOP contents. With adding of the DOP, the interaction force among the PVC macromolecules was reduced, and the mobility of chain segment was increased. In addition, the melt viscosity and processing power of PVC-TPE could be effectively reduced with adding of the acrylate monomer. While the Tg of the acrylate monomer was much lower, the shore hardness, the tensile strength, and the tear strength of PVC-TPE were decreased.In the second approach, the effect of processing technology of DPVC, reaction time and the temperature of DPVC and BA, the type of acrylate monomer and dosage on the mechanical properties and the processing performance of DPVC-TPE were studied.The results showed that, in order to get the best performance of DPVC-TPE, PVC-1300 was processed 2 hours with 1mol/L solution of NaOH at 100℃. With the acrylate monomer adding, the glass transition temperature (Tg) of the DPVC-TPE shifted to low temperature, and the mechanical strength, the hardness, the compression deformation rate of the DPVC-TPE were all decreased, wilth the thermal stability improved, and the resilience enhanced. With the increasing of reaction temperature of BA and DPVC, the Tg of the TPE was shifted to the high temperature, the storage modulus increased gradually, and the processing performance became better.Another, PVC/NBR thermoplastic elastomer were prepared with PVC (PVC-1300, PVC-2500), nitrile rubber (NBR) and some of the plasticizer by melt blending. The results showed that, with the increasing of the NBR contents, the tensile strength, the tear strength, the hardness and the compression permanent deformation rate of the PVC/NBR thermoplastic elastomer were declined, and the elongation at bread of the PVC/NBR thermoplastic elastomer had the maximun value. The balance torque increased, the plastic times extended; the migration rate and the extractability of plasticizer were gradually decreased.