聚(丁二酸丁二醇-co-二苯醚二甲酸丁二醇)酯/聚对苯二甲酸丁二醇酯复合材料的制备及性能

Preparation and properties of poly(butylene succinate-co-butylene diphenyl ether dicarboxylate)/polybutylene terephthalate composites

聚对苯二甲酸丁二醇酯(PBT)是半结晶热塑性聚合物,具有出色的尺寸稳定性、高的刚度和硬度、良好的耐化学性、力学性能和可加工性等优良特点。但其抗冲击性较低、韧性较差。采用将PBT与具有优异韧性的聚(丁二酸丁二醇-co-二苯醚二甲酸丁二醇)酯(PBSO)进行熔融共混以改善PBT的韧性。首先以二苯醚二甲酸(OBBA)、丁二酸(SA)和丁二醇(BDO)为单体,以钛酸四丁酯为催化剂,采用先酯化后缩聚的两步法合成了PBSO。然后将不同质量比的PBSO与PBT进行熔融挤出共混,研究复合材料的力学韧性、PBSO与PBT的相容性、结晶行为、热稳定性以及流变性能等。FT-IR、^(1)H NMR、GPC测试分析了所合成PBSO的结构。力学性能测试表明,20wt%PBSO/PBT复合材料的拉伸强度为40.3 MPa,断裂伸长率达到82.1%,断裂能增加到24.7 MPa,冲击强度达到较大值23.2 kJ/m^(2),具有较高的拉伸强度和良好的韧性。动态热机械分析(DMA)和SEM结果发现,PBSO对PBT具有增容效果,PBSO/PBT是部分相容共混体系。差示扫描量热(DSC)和广角X射线衍射(WAXD)结果显示,非晶聚合物PBSO的加入,降低了PBT的结晶度,但未改变PBT的晶体结构。热重分析(TGA)分析可知,PBSO/PBT复合材料具有良好的加工热稳定性。

Polybutylene terephthalate(PBT)is a semi-crystalline thermoplastic polymer with excellent dimensional stability,high stiffness and hardness,good chemical resistance,mechanical properties and processability.But its impact resistance is low and toughness is poor.PBT was melt blended with poly(butylene succinate-co-butylene diphenyl ether dicarboxylate)(PBSO),which has excellent toughness,to improve the toughness of PBT.Firstly,PBSO was synthesized by a two-step method of esterification and polycondensation,using diphenyl ether dicarboxylic acid(OBBA),succinic acid(SA)and butanediol(BDO)as monomers,and tetrabutyl titanate as catalyst.Then,PBSO/PBT with different mass ratios of PBSO and PBT were blended by melt-extrusion to study the toughening effect of PBSO on PBT.The mechanical toughness of blends,the compatibility of PBSO and PBT,crystallization behavior,thermal stability and rheological properties were studied.The structure of PBSO was characterized by FTIR,1H NMR and GPC.The mechanical performance test show that the tensile strength of the 20wt%PBSO/PBT composite material is 40.3 MPa,the elongation at break reach to 82.1%,the breaking energy increas to 24.70 MPa,and the impact strength is 23.2 kJ/m^(2),indicating a higher tensile strength and good toughness.Dynamic mechanical analysis(DMA)and SEM results indicate that PBSO has a compatibilizing effect on PBT,and PBSO/PBT is a partially compatible blend system.DSC and wide-angle X-ray diffraction(WAXD)results show that the addition of amorphous polymer PBSO reduce the crystallinity of PBT,but do not change the crystal structure of PBT.Thermogravimetric analysis(TGA)analysis demonstrated that the PBSO/PBT composite has a good processing thermal stability.