Study On Thermoplastic Polyurethane Elastomer Toughening PVC

Polyvinyl-chloride (PVC) is one kind of general resins with fine performances and low price, but PVC must be modified because of its brittleness, bad thermal stability and poor processability. PVC composites with high performances can be obtained by blending with thermoplastic polyurethane elastomer (TPU) to carry toughening modification.Firstly polyether thermoplastic polyurethane elastomer had been prepared successfully by polyethylene glycol (PEG), toluene diisocyanate (TDI) and 1, 4-butylene glycol (BDO) as basic materials. According to orthogonal experiment the optimal craft conditions of synthesis reaction could be summarized: hard segment content Ch was 40%, isocyanate index R was 1.02, reaction temperature T was 80℃, reaction time t was 1.5 h. Segment unit construct and performance of TPU could be confirmed through Fourier Transform Infrared Spectra (FTIR), elemental analysis, Differential Scanning Calorimetry (DSC).Secondly PVC/TPU blends had been prepared by two roll rubber mixing mill. The effects of 5 factors which were TPU contents and types, plasticizer contents, thermal stabilizer types and contents, fills on tensile strength, unnotched impact strength, elongation at break were discussed. It was found that affinity of polyester TPU with PVC was superior to polyether TPU, so polyester TPU was chose as research object and was realized toughening and reinforcing to PVC. The optimum prescription of PVC/TPU/modified kaolin blending material was optimized through experiments: PVC content was 80%, TPU content was 20%, modified kaolin content was 4%, DOP content was 8%, dibutyl tin dilaurate thermal stabilizer content was 3 %, calcium stearate content was 1%, zinc stearate content was 1%, paraffin and stearic acid content was 1%. Tensile strength of PVC/TPU/modified kaolin blending material had been enhanced 1.4 times than PVC material, elongation at break had been enhanced 12.63 times, unnotched impact strength had been enhanced 3.97 times. Oil and solvent resistant performance of blending material was superior. Thermal stability performance and thermal decomposition temperature of PVC had been improved obviously by TPU. Moreover, blending time and stability time on two roll rubber mixing mill had been enhanced and processing fluidity of PVC also had been improved. From microscopic morphology characteristics of PVC/TPU blending material it was showed that TPU could initiate massive crazes then induce PVC matrix to cause brittle-ductile transition, which enhanced material's performances.Reinforcing is realized by filling-compounding of PVC/TPU blending and kaolin. The anticipated toughening and reinforcing goal has been achieved by PVC/TPU/modified kaolin blending material.