PBT对ABS力学性能及耐应力开裂性能的影响

Effect of PBT on Mechanical Properties and Stress Cracking Resistance of ABS

使用聚对苯二甲酸丁二醇脂(PBT)对丙烯腈-丁二烯-苯乙烯共聚物(ABS)树脂进行共混改性,通过电子万能试验机、扫描电镜、接触角、差示扫描量热分析等,研究了PBT/ABS的力学性能、断面形貌、表面能、结晶度和相容性。采用格里菲思理论计算出材料的应力强度因子(K1C),采用预制应力-溶剂释放应力法,检测了耐应力开裂性能。结果表明,加入PBT后,ABS的拉伸强度和熔体流动性提升,表面能升高,冲击强度降低。当PBT含量为4份时,合金的拉伸强度从40.12 MPa提升到46.23 MPa,熔体流动速率从12.32 g/10 min提升到15.33 g/10 min,表面能从25.7 mN/m提升到30.2 mN/m,冲击强度从25.67 kJ/m^2提升到23.41 kJ/m^2。合金断面的微观形貌逐渐平整,ABS的玻璃化转变温度向低温偏移。当加入5份PBT后,ABS的耐应力开裂时间从8 s增加到21 s。

Acrylonitrile-butadiene-styrene copolymer(ABS)resin was modified with polybutylene terephthalate(PBT)by melt blending.Mechanical properties,micro-morphology,surface energy,crystallinity and compatibility of the PBT/ABS were investigated by electronic universal testing machine,SEM,contact angle and DSC analysis,respectively.The stress intensity factor(KIC)of the material was calculated by Griffith theory.The stress cracking resistance time was measured by the method of precast stress-solvent release.The results showed that tensile strength,melt fluidity and surface energy of ABS increased with the addition of PBT,while the impact strength decreased.When the PBT content was 4,the tensile strength of the alloy increased from 40.12 MPa to 46.23 MPa.The melt flow rate increased from 12.32 g/10 min to 15.33 g/10 min.The surface energy increased from 25.7 mN/m to 30.2 mN/m.And the impact strength increased from 25.67 kJ/m^2 to 23.41 kJ/m^2.The microstructure of alloy section became smooth.The glass transition temperature of ABS moved to lower temperature.When the PBT content was 4,the stress cracking resistance time increased from 8 s to 21 s.