摘要传统聚乙烯地膜的大量使用已给我国造成了严重的土地污染，推广使用全生物降 解农用地膜被认为是解决这一问题最为根本的方式。在众多的全生物降解地膜中，聚 乳酸（PLA）/聚己二酸-对苯二甲酸丁二酯（PBAT）生物基全降解地膜因巧妙结合了 PLA 强度高和 PBAT 柔性好的优点而备受人们青睐。78318

本文采用熔融共混的方式制备出不同反应性助剂增容改性的 PLA/PBAT 复合材 料，通过哈普转矩流变仪、DMA、SEM、GPC 和万能拉伸试验机研究了不同相容剂 对 PLA/PBAT 共混物拉伸性能、微观结构和热性能的影响；然后确定出最佳相容剂的 种类，吹塑制得不同 PLA 含量的生物基全降解农用地膜，并重点研究了所制地膜的 光氧老化行为。

结果表明：乙烯丙烯酸甲酯接枝甲基丙烯酸缩水甘油酯(EMA-GMA)、乙烯丙烯 酸丁酯接枝甲基丙烯酸缩水甘油酯(EBA-GMA)和过氧化二苯甲酰(BPO)三种反应性 助剂的加入均可以改善 PLA/PBAT 复合材料的流变性能；加入 EBA-GMA、EMA-GMA 和 BPO 后，PLA/PBAT 复合材料的初始储能模量分别增大了 52MPa、60MPa 及 97MPa； 材料的断裂伸长率从未加入相容剂时的 19。27% 依次增大至 44。32%、 57。65% 和 140。13%；光氧老化实验的结果表明，随着紫外光照射时间的延长，三种 PLA/PBAT 合金薄膜的重均分子量及力学性能都表现出了明显的下降趋势；且随着薄膜中 PLA 含量的减少，其光氧老化速率不断加快，其中光氧老化 192h 后，PLA 含量为 55phr、 45phr 和 35phr 的合金薄膜的重均分子量分别减少至降解之前的 31%、23%和 17%， 质量损失率分别为 1。3%、2。4%和 3。2%，拉伸强度依次降低了 15。61MPa、22。91MPa 和 22。98MPa。此外，光氧老化还会造成 PLA/PBAT 合金薄膜透明性的降低。

毕业论文关键词：聚乳酸；聚己二酸-对苯二甲酸丁二酯；地膜；光氧老化

Abstract The extensive use of polyethylene film has caused serious soil pollution in our country, and it is considered as the most fundamental way to solve this  problem。In the  numerous full bio degradable mulch film, poly lactic acid (PLA) / poly (adipic acid butylene terephthalate) (PBAT) based bio degradable mulch film because of the ingenious combination of the high strength of the PLA and PBAT flexible good advantages and much people of all ages。

In this paper, PLA/PBAT composites with different reactive additives were prepared by melt blending。Through happ torque rheometer, DMA, SEM, GPC and universal tensile testing machine of different compatibilizers on the tensile properties of PLA / PBAT blends, microstructure and thermal properties influence; then identifies the best compatibility agent type, blow molding of different content of PLA bio based full degradable mulching film, and focus on the of film photooxidation aging behavior。

The results show that: Ethylene methyl acrylate grafted with glycidyl methacrylate (EMA-GMA) and ethylene butyl acrylate grafted with glycidyl methacrylate (EBA-GMA) and two benzoyl peroxide (BPO) rheological property by adding three kinds of reactive additives can improve PLA/PBAT composite materials; adding EBA-GMA, EMA-GMA and BPO after the initial storage PLA/PBAT the composite modulus increased by 52MPa, 60MPa and 97MPa; the elongation never adding compatibilizer when 19。27% increases to 44。32%, 57。65% and 140。13%; the light aging experiment results show that, with the exposure time prolonged, three kinds of PLA/PBAT alloy film molecular weight and mechanical performance a significant downward trend; and with the decrease of PLA content in the films, the aging rate continues to accelerate, the aging of 192h, the content of PLA For alloy films 55phr, 45phr and 35phr heavy were molecular weights were reduced to before the degradation of 31%, 23% and 17%, the mass loss rate was 1。3%, 2。4% and 3。2%, the tensile strength in turn reduce the 15。61MPa, 22。91MPa and 22。98MPa。 In addition, the degradation of PLA/PBAT alloy film transparency is caused by the aging of oxygen and oxygen。