Structural, morphological and mechanical characteristics of polyethylene, poly(lactic acid) and poly(ethylene-co-glycidyl methacrylate) blends
Structural, morphological and mechanical characteristics of polyethylene, poly(lactic acid) and poly(ethylene-co-glycidyl methacrylate) blends
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DOI：
10.1007/s13726-013-0126-6
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发表时间：
2013-04-01
影响因子：
3.1
通讯作者：
Grohens, Yves
中科院分区：
文献类型：
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作者：
Djellali, Souad;Haddaoui, Nacereddine;Grohens, Yves
在这项工作中，非增容和增容的低密度聚乙烯（LDPE）和聚乳酸（PLA）的共混物进行了几项调查：傅里叶变换红外光谱（FTIR），形态分析和力学测试（拉伸，冲击，显微硬度）。乙烯-甲基丙烯酸缩水甘油酯共聚物（EGMA）用作相容剂。LDPE/PLA样品中PLA的百分比范围为0至100重量%，而EGMA以2、5、7、10、15和20份/百份（phr）的浓度添加到共混物60/40（LDPE/PLA）中。FTIR分析表明LDPE和PLA之间没有任何相互作用，但加入增容剂后，EGMA的环氧基团与PLA的羧基或羟基之间发生了反应。拉伸和冲击试验表明，除了组合物80/20（LDPE/PLA）之外，随着PLA的掺入，LDPE的延展性损失。然而，添加15 phr的EGMA导致断裂伸长率（约三倍的值的不相容的共混物）和冲击强度的最大增加，但观察到的拉伸强度的边际改善。SEM照片证实，力学性能的提高是由于EGMA的存在改善了不同相之间的界面粘合。不同共混物（未增容或增容）的显微硬度值与宏观力学性能（拉伸强度和冲击强度）吻合良好。
In this work, uncompatibilized and compatibilized blends of low density polyethylene (LDPE) and poly(lactic acid) (PLA) were subjected to several investigations: Fourier transform infrared (FTIR) spectroscopy, morphological analysis and mechanical testing (tensile, impact, microhardness). The copolymer (ethylene-co-glycidyl methacrylate) (EGMA) was used as compatibilizer. The percentages of PLA in LDPE/PLA samples ranged from 0 to 100 wt% while the EGMA was added to the blend 60/40 (LDPE/PLA) at concentrations of 2, 5, 7, 10, 15 and 20 parts per hundred (phr). FTIR analysis showed the absence of any interaction between LDPE and PLA, but after addition of compatibilizer, reactions between epoxy groups of EGMA and carboxylic or hydroxyl groups of PLA were confirmed. Tensile and impact tests revealed a loss of ductility of LDPE with the incorporation of PLA, except for the composition 80/20 (LDPE/PLA). However, the addition of 15 phr of EGMA led to the maximum increase in the elongation-at-break (about three times the value of uncompatibilized blend) and in the impact strength, but a marginal improvement was observed for tensile strength. SEM micrographs confirmed that the enhancement of mechanical properties is due to the improvement of the interfacial adhesion between different phases owing to the presence of EGMA. The microhardness values of the different blends (uncompatibilized or compatibilized) were in good agreement with the macroscopic mechanical properties (tensile and impact strengths).