PVAL/改性淀粉复合发泡材料的制备及性能

以玉米淀粉为原料,通过丙烯酸塑化改性法制备玉米改性淀粉。以柠檬酸和NaHCO_3作为复合发泡剂,甘油、二乙醇胺和山梨醇作为复合增塑剂改性聚乙烯醇(PVAL),与改性淀粉辅以其它加工助剂,利用模压成型发泡制备了一种可生物降解的PVAL/改性淀粉复合发泡材料。重点探究了改性淀粉含量对复合发泡材料生物降解性能和发泡形态的影响,NaHCO_3发泡剂含量对复合材料耐水性能、力学性能和发泡性能的影响,助剂滑石粉含量对复合材料发泡性能的影响。结果表明,当改性淀粉质量分数为40%,复合发泡剂NaHCO_3、滑石粉及柠檬酸质量分数均为4.0%时,所得发泡材料的生物降解性能较好,拉伸强度为2.134 MPa,断裂伸长率为79.1%,泡孔分布均匀,泡孔结构良好,形状较规整。

Preparation and Properties of PVAL/Modified Starch Composite Foaming Materials

The modified starch was produced through a method of acrylic plasticizing modification by using corn starch as raw materials. A biodegradable polyvinly alcohol (PVAL)/modified starch composite foaming material was prepared by the moulding foaming process,taking NaHCO3 and citric acid as composite foaming agent,glycerol,diethanolamine and sorbitol as composite plasticizers to modified PVAL,and modified starch with other processing additives. The effects of the content of modified starch on the biodegradation properties and cell morphology of the composite foaming material,the impacts of the content of NaHCO3 foam-ing agent on the water resisting properties,mechanical properties and foaming properties,and the influences of the content of talcum powder on foaming properties of PVAL/modified starch composite foaming material were highly investigated. Results indicate that when the mass fraction of modified starch is 40%,the mass fractions of sodium bicarbonate,citric acid and talc are all 4.0%,the biodegradation property of the foaming material is preferable and the tensile strength is 2.134 MPa,the elongation at break is 79.1%. What's more,the pore is uniformly distributed with good structure and regular shape.