增塑体系对蔗渣基可生物降解复合材料性能的影响

利用甘油、甲酰胺和乙二醇对淀粉/蔗渣进行增塑改性,通过挤出注塑制备出了聚乳酸(PLA)/淀粉/蔗渣可生物降解复合材料。研究了增塑改性剂种类和含量对复合材料加工性能、流变性能、力学性能以及吸水性的影响。结果表明:选用的3种增塑剂对淀粉/蔗渣均有明显的增塑作用,且甲酰胺的增塑效果最好;当PLA、淀粉和蔗渣质量比为6:2:2时,增塑制得的复合材料的拉伸强度均在35 MPa以上;复合材料在4天后的吸水率均大于10%,其中由甲酰胺增塑复合材料的吸水率高达25%;增大增塑剂含量,有助于改善复合材料加工性能,但会增大复合材料的吸水率和降低复合材料的拉伸强度。

Effect of Plasticizers on Properties of Bagasse Fiber Based on Biodegradable Composites

The PLA/starch/bagasse biodegradable composites were prepared by the process of extrusion and injection, by using glycerine, methanamide and ethanediol as plasticizing modifier. The effects of type and content of plasticizing on processing properties, rheological properties, mechanical properties and water absorption of prepared composites were studied. The results showed that the plasticizing modifiers selected had an obvious plasticizing effect, and methanamid showed a best plasticizing effect for starch/bagasse. The tensile strength of all prepared composites was above 35 MPa in the case that the mass ratio of PLA, starch and bagasse was 6:2:2. The fourth day water absorption of all prepared composites was above 10%, and the one plastified by methanamide was reaching up to 25%. Increasing content of plasticizers could improve processing properties, but also could increase water absorption and decrease tensile strength of prepared composites.