聚酯型热塑性聚氨酯弹性体的合成及对聚氯乙烯的增韧

Effects of Polyester Thermoplastic Polyurethane Elastomer on Toughening Modification of Polyvinyl Chloride

以二苯基甲烷二异氰酸酯(MDI)、聚ε-己内酯多元醇(PCL)及1,4-丁二醇(1,4-BDO)为原料,成功设计合成了聚酯型热塑性聚氨酯弹性体(TPU)。合成条件:异氰酸酯指数R=0.98,温度60~70℃,反应时间1 h。通过元素分析、红外光谱、核磁共振、差示扫描量热分析、凝胶色谱等测试,确定了TPU中的硬段含量及化学结构。通过与聚氯乙烯(PVC)进行共混,评价了合成TPU对PVC的增韧效果,经力学性能测试、差示扫描量热分析以及扫描电子显微镜观察研究了共混材料的结构与性能,揭示增韧机理。结果表明,合成TPU与PVC之间具有良好的相容性,对PVC有良好的增韧作用,当m(PVC)∶m(TPU)=170∶30时,力学性能优于市售TPU牌号。合成的TPU随硬段比例增加,PVC/TPU共混物材料拉伸强度变化不大,断裂伸长率下降,而冲击强度大幅提高,实现了对PVC的增韧。

The polyester type thermoplastic polyurethane elastomer（TPU） was successfully designed and synthesized with diphenyl methane diisocyanate（MDI） and poly-caprolaclone glycol（PCL） and 1,4-butanediol（1,4-BDO） as raw material.Synthesis condition is MDI isocyanate index of 0.98;tpolymerization temperature of 60～70 ℃,the reaction time of 1 h.By elemental analysis,FT-IR,NMR,DSC,gel chromatography,the hard segment content and chemical structure of the TPU were determined.Through blending with PVC,toughening effects of synthetic TPU on PVC were evaluated.The structure and properties of PVC/TPU blends were characterized by the mechanics performance test,differential scanning calorimetry（DSC） and scanning electron microscope（SEM）.Results show that the blends haves good compatibility between TPU and PVC and good toughening effect on PVC.With the TPU mass fraction of 15% in PVC/TPU blends,the mechanical performance is better than that of commercially available TPU materials.With rising of hard segment rate of the synthesized TPU,the tensile strength of PVC/TPU blends changes little,elongation at break decreases,while the impact strength greatly increases,toughening of PVC is realized.