生物质纤维和改性木质素对聚乳酸结晶性能的影响

采用改性木质素(MZS)作为成核剂,生物质纤维(BF)作为增强剂,通过双螺杆挤出机制备了生物降解的聚乳酸(PLA)/BF/MZS材料。采用差式扫量热仪(DSC)、电子万能试验机和扫描电子显微镜(SEM)分析了BF和MZS对PLA材料性能的影响。结果表明,BF和MZS有效提高了PLA的结晶能力和力学性能。当BF和MZS的含量分别为15%和1%时,PLA材料结晶度提高至67.1%,在50℃/min降温速率下仍具有较高的结晶能力。105℃等温结晶时,15%BF和1%MZS的PLA材料半结晶时间降低至9.0 s,比纯PLA缩短了72.2%。当PLA含有3%BF和1%MZS时,拉伸强度和冲击强度分别为70.1 MPa和7.4 kJ/m^2,比纯PLA分别提高了7.8%和10.4%,根据SEM显示,当BF含量为3%时,在PLA材料中分布较均匀。

Effect of Biopolymer Fiber and Modified Lignin on Crystallization Properties of Polylactic Acid

The biodegradable PLA/BF/MZS composite was prepared through a twin-screw extruder by using the modified ligin(MZS)as the nucleating agent and the biopolymer fiber(BF)as enhancer.Differential scanning calorimetry(DSC)and Electronic universal testing machine and Scanning electron microscope(SEM)were used to analyze the effect of BF and MZS on properties of PLA.It showed that BF and MZS effectively enhanced the crystallization ability and mechanical properties of PLA.When the content of BF and MZS was 15%and 1%,the crystallinity of PLA material increased to 67.1%,respectively.It still had high crystallization ability at the temperature drop rate of 50℃/min.At 105℃isothermal crystallization,the semi-crystallization time of PLA materials with 15%BF and 1%MZS was reduced to 9.0 s,which was 72.2%shorter than pure PLA.When PLA contains 3%BF and 1%MZS,the tensile strength and impact strength were 70.1 MPa and 7.4 kJ/m^2,compared to pure PLA were increased by 7.8%and 10.4%,respectively,SEM showed that when BF content was 3%,the distribution of BF in PLA material was more uniform.