【摘要】 采用溶液共混的方法,用二氧化碳共聚物脂肪族聚碳酸酯(PPC)、改性淀粉对聚乳酸(PLA)改性,制备出韧性得以改善的PLA/PPC/改性淀粉共混薄膜。通过研究共混薄膜拉伸性能与共混组成配比的关系,试验结果表明,加入30%甘油对淀粉进行糊化,对淀粉改性效果较好。随着PPC组分的增加,提高了共混膜的断裂伸长率,增强了其韧性,但是加入量较大时会降低共混膜的拉伸强度,因此应控制其加入比例。PLA/PPC/改性淀粉(甘油/淀粉=3∶7)3组份质量比为60∶20∶20的三元共混膜具有良好的断裂伸长率,达到增韧效果,同时拉伸强度并未下降太多。更多还原

【Abstract】 Poly(lactic acid)(PLA) was blended with poly(propylene carbonate)(PPC),a copolymer of carbon dioxide and alkyleneoxide,and modified starch in solvent and a blending film with improved toughness was obtained.Tensile tests of the films with different blending compositions showed that 30% glycol added during the starch gelatinization optimized the properties of the end blending film;and the failure elongation and the toughness of the film improved with the increasing of the mass ratio of PPC.But the ratio of PPC should be controlled under certain value since too much of it may decrease the stretching strength of the blending films.As a whole,the ternary blending film of PLA/PPC/modified starch(with the mass ratio of glycol/starch at 3/7) showed an optimized elongation at failure and consequently the toughness was distinguished improved when the mass ratio of three components was 60:20:20,without sharp decrease of stretching strength.更多还原