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采用熔融共混挤出法制备改性纳米羟基磷灰石(HA)/聚乳酸(PLA)-聚己二酸丁二酯-对苯二甲酸丁二酯(PBAT)复合降解材料,利用差示扫描量热仪(DSC)、流变仪、电子拉伸机、扫描电镜(SEM)等,对其结晶、流变行为、力学性能、冲击性能、表面结构等进行了研究。DSC结果表明:随着改性纳米HA添加量的增多,HA/PLA-PBAT共混体系的玻璃化转变温度先升高后下降;冷结晶温度逐渐下降,降低了13℃,结晶能力有所提高;结晶度由24.33%增加到33.47%。流变行为显示共混体系黏度随剪切速率的增大而减小,属非牛顿流体。此外,随着改性纳米HA的增多,HA/PLA-PBAT共混体系储存模量和损耗模量逐渐减小;屈服强度、缺口冲击强度、拉伸强度先增大后减小,当共混体系中改性纳米HA添加量为2%(80/20/2)时,达到最大值。SEM观察发现,少量改性纳米HA可以均匀分散在PLA-PBAT基体中并能显著提高其韧性。
The modified nano-hydroxyapatite (HA) / polylactic acid (PLA) -polybutylene adipate-polybutylene terephthalate (PBAT) composite degradation material was prepared by melt blending extrusion. Scanning calorimetry (DSC), rheometer, electronic stretching machine and scanning electron microscope (SEM). The crystallization, rheological behavior, mechanical properties, impact properties and surface structure were studied. The DSC results showed that the glass transition temperature of HA / PLA-PBAT blends first increased and then decreased with the increase of the amount of modified nano-HA; the temperature of cold crystallization decreased gradually, decreased by 13 ℃, and the crystallization ability increased The crystallinity increased from 24.33% to 33.47%. Rheological behavior shows that the viscosity of the blend system decreases with increasing shear rate, which is a non-Newtonian fluid. In addition, the storage modulus and loss modulus of HA / PLA-PBAT blends decreased with the increase of modified nano-HA. The yield strength, notched impact strength and tensile strength first increased and then decreased, In the system, the content of modified nano-HA reached the maximum when it was 2% (80/20/2). SEM observation showed that a small amount of modified nano-HA can be uniformly dispersed in the PLA-PBAT matrix and can significantly improve its toughness.