高性能环境友好PLA/PPC/PLA-g-GMA复合材料的制备与性能研究

通过聚乳酸(PLA)与甲基丙烯酸缩水甘油酯(GMA)制备PLA-g-GMA接枝共聚物,将PLA-g-GMA与PLA、聚碳酸亚丙酯(PPC)熔融共混,制备PLA/PPC/PLA-g-GMA共混材料,研究PLA-g-GMA的含量对PLA/PPC/PLA-g-GMA共混材料的热学性能、力学性能、光学性能以及微观形态的影响。结果表明:PLA与GMA可以成功进行熔融接枝反应,生成的PLA-g-GMA可以改善PLA与PPC之间的相容性。随着PLA-g-GMA含量的增加,共混材料的维卡软化温度逐渐升高,而其起始分解温度及完全分解温度略有降低。当共混材料的拉伸强度保持不变,共混材料的断裂伸长率、冲击强度随PLA-g-GMA含量的增加呈现先增加后降低的趋势。PLA-g-GMA含量为10%时,共混材料的力学性能最佳,其断裂伸长率、冲击强度分别为236.46%、5876.90 J/m^(2),此时冲击断面表现明显的韧性断裂特征。共混材料的雾度随PLA-g-GMA含量的增加逐渐降低,而透过率略有提升,整体表现优异的光学性能。

Effect of Melt Mixing Time in Internal Mixer on Mechanical Properties and Crystallization Behavior of Glycidyl Methacrylate Grafted Poly (Lactic Acid)

Glycidyl methacrylate (GMA) was grafted onto poly (lactic acid) (PLA) by melt mixing in internal mixer using dicumyl peroxide (DCP) as an initiator. The results from proton nuclear magnetic resonance (1H-NMR) and Fourier transform infrared (FTIR) spectroscopy indicated that the grafting reaction of GMA onto PLA took place successfully. The impact strength of PLA-g-GMA was significantly higher than that of pure PLA. The crystallinity of PLA, obtained from differential scanning calorimetry (DSC), decreased after grafting. In order to obtain the optimal mixing conditions, the mixing time was varied into 7, 10 and 14 min. The optimum mixing time of 10 min was found to give the optimum mechanical properties of glycidyl methacrylate grafted poly (lactic acid) (PLA-g- GMA). However, the mixing time played no important role in impact behavior of PLA-g-GMA. In addition, the highest crystallinity was obtained with the PLA-g-GMA prepared with the mixing time of 7 min.

PBS-g-GMA对PLA/PBS共混体系的增容性

采用熔融法制备聚丁二酸丁二醇酯(PBS)与甲基丙烯酸缩水甘油酯(GMA)的接枝物(PBS-g-GMA),并以此接枝物为增容剂,制备聚乳酸(PLA)/PBS-g-GMA/PBS共混物。用傅里叶红外光谱仪和返滴定法对接枝物的接枝率进行表征,通过扫描电子显微镜(SEM)表征共混物的形貌,并研究了GMA和过氧化苯甲酰(BPO)用量对共混物拉伸性能及动态力学性能的影响。结果表明,当PBS-g-GMA中PBS/BPO/GMA份数比为100/0.5/6时,接枝率达到最大值2.81%。PBS-g-GMA的加入使共混体系有良好的相容性。当PLA/PBS-g-GMA/PBS的份数比为80/15/5,其中PBS-g-GMA中PBS/BPO/GMA为100/0.5/6时,与PLA/PBS相比,断裂伸长率由8.60%提高到63.92%,25℃时的储能模量由2.44GPa降低到2.18GPa。