聚乳酸/改性甘蔗纤维复合材料的制备与性能分析

Preparation and Performance Analysis of Polylactic Acid/Modified Sugarcane Fiber Composites

以低分子量聚乙二醇(PEG)为增塑剂,马来酸酐改性的甘蔗纤维(MSF)为成核剂,采用熔融共混的方式制备PLA/MSF/PEG复合材料,并对复合材料的结晶行为、晶体形貌、力学和表面亲水性进行研究。结果表明:表面改性的MSF可作为异相成核剂,显著提高PLA的结晶能力;增塑剂PEG和成核剂MSF的协同加入,能够进一步提高PLA的结晶速率,并增大球晶尺寸。增塑剂PEG的加入,能够明显提高PLA/MSF/PEG的断裂伸长率,但使复合材料的拉伸强度和模量下降。与PLA/PEG共混物相比,PLA/MSF/PEG共混物具有更高的拉伸强度和模量。PLA/MSF(3%)/PEG(10%)的综合性能较好,与纯PLA相比断裂伸长率提高468.7%,拉伸强度降低48.7%左右。因此,增塑剂PEG与改性纤维MSF协同改性,使PLA/MSF/PEG共混物具有更优异的力学性能和结晶性能,能够进一步扩大PLA材料的应用范围。

The PLA/MSF/PEG were prepared by melt blending with low molecular weight polyethylene glycol(PEG)as plasticizer and maleic anhydride modified sugarcane fiber(MSF)as nucleating agent.The crystallization behavior,crystal morphology,mechanical properties and surface hydrophilicity of the composites were studied.The results show that the surface-modified MSF can be used as a heterogeneous nucleating agent to significantly improve the crystallization ability of PLA,and the synergistic addition of plasticizer PEG and nucleating agent MSF can further increase the crystallization rate of PLA and the spherulite size.The addition of plasticizer PEG can significantly increase the elongation at break of PLA/MSF/PEG,but it will decrease the tensile strength and modulus of composites.Compared with PLA/PEG blends,PLA/MSF/PEG blends have higher tensile strength and modulus.PLA/MSF(3%)/PEG(10%)composites have better comprehensive properties.Compared with pure PLA,the elongation at break is increased by 468.7%,and the tensile strength is reduced by 48.7%.Therefore,the PLA/MSF/PEG blend modified by the plasticizer PEG and the modified fiber MSF has more excellent mechanical properties and crystalline properties,which can further expand the application range of PLA materials.