氙灯老化对立构复合PLA/PBS共混物的结晶与力学性能的影响

Effects of Xenon Lamp Aging on Crystallization and Mechanical Properties of SC-PLA/PBS Blends

利用生物可降解聚乳酸(PLA)作为增强相,通过熔融共混法制备了一系列PLA和聚乳酸立构复合物(SC-PLA)改性聚丁二酸丁二醇酯(PBS)共混物,并对PLA/PBS以及SC-PLA/PBS共混物进行氙灯老化处理。利用扫描电子显微镜(SEM)、广角X射线衍射仪(WAXD)、差示扫描量热仪(DSC)、偏光显微镜(POM)、万能试验机和氙灯老化仪测试了老化前后PBS基共混物的微观形态、结晶及力学性能。结果表明,PLA的加入提高了PBS的拉伸强度,细化了晶粒且未改变晶型结构,同时结晶度也有所提高;与PLA/PBS相比,SC-PLA改性PBS共混物有效地提高了共混物的拉伸强度和耐候性;在氙灯老化960 h条件下,PLA/PBS以及SC-PLA/PBS共混物的结晶度和拉伸模量均明显提高,而拉伸强度有轻微的下降。

Taking biodegradable polylactic acid(PLA)as enhanced phase,a series of PLA and polylactic acid stereotactic complex(SC-PLA)modified polybutylene succinate(PBS)blends were prepared by melt blending method,and the PLA/PBS and SC-PLA/PBS blends were treated by xenon lamp aging instrument.The microscopic morphology,crystallization and mechanical properties of PBS-based blends before and after aging were examined by scanning electron microscopy(SEM),wide-angle X-ray diffractometer(WAXD),differential scanning calorimetry(DSC),polarization microscope(POM),universal testing machine and xenon lamp aging instrument.The results show that the addition of PLA improves the tensile strength of PBS,refines the crystals size and does not change the crystalline structure,and the crystallinity is improved.Comparing with PLA/PBS,the SC-PLA could more effectively improve tensile strength and weather resistance of the PBS-based blend.Under the period of xenon lamp aging for 960 h,the crystallinity and tensile modulus of PLA/PBS and SC-PLA/PBS blends distinctly increase,while corresponding tensile strength slightly decreases.