复合增塑剂改性PLA共混物的结构与性能

采用HM-128,HM-529两种增塑剂复配对聚乳酸(PLA)进行熔融共混改性,研究增塑剂用量对共混物的流变性能、拉伸性能和微观形态结构的影响,筛选增塑剂复配最佳配比和用量.结果表明,确定HM-128与HM-529质量比为1:1保持不变,随着增塑剂用量增加,共混物的平衡转矩和拉伸强度降低、断裂伸长率增加、撕裂强度呈先增加后减小的趋势,淬冷断面由平整变为粗糙;在复合增塑剂总质量分数16%不变的情况下,随着复配增塑剂中HM-529含量的增加,共混物的平衡转矩增大、断裂伸长率提高,当HM-128/HM-529质量比=1/1时,共混物的拉伸强度、断裂伸长率和撕裂强度分别为35.6 MPa,209.2%和30.6 N/cm,淬冷断面非常粗糙,获得了良好的增韧效果,共混物的综合性能最理想.

Structure and Properties of PLA/Plasticizer Blends

The polylactic acid (PLA) were modified by the mixture of HM-128 and HM-529. The optimum dosage and proportion of mixed plasticizer were studied by investigating the influences of them on rheological properties,tensile properties and microstructure of blends. The results show that when the mass ratio between HM-128 and HM-529 is 1/1 the tensile strength and the balance torque of blends decrease, the elongation at break increases,the tear strength increases first and then decreases with the increase of plasticizer dosage. Meanwhile the brittle cold section becomes rough from smooth. Based on the 16% of composite plasticizer dosage,the balance torque and the elongation at break all increase with the increase of the content of HM-529 in the composite plasticizer. When the ratio of HM-128/HM-529 is 1/1, the blends is characterized with tensile strength of 35.6 MPa , tear strength of 30.6 N/cm and the elongation at break of 209.2%, brittle cold section is very rough. The toughening effect of the blends is good and the comprehensive properties are optimal.