Morphology, mechanical, and rheological properties of poly(lactic acid)/ethylene acrylic acid copolymer blends processing via vane extruder
Morphology, mechanical, and rheological properties of poly(lactic acid)/ethylene acrylic acid copolymer blends processing via vane extruder
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DOI：
10.1002/app.40146
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发表时间：
2014-04
影响因子：
3
通讯作者：
Yongqing Zhao;Fuquan Chen;Zheng‐Huan Wu;Yanhong Feng;J. Qu
中科院分区：
文献类型：
--
作者：
Yongqing Zhao;Fuquan Chen;Zheng‐Huan Wu;Yanhong Feng;J. Qu
本文首次研究了用新型叶片挤出机对聚乳酸(PLA)和乙烯-丙烯酸(EAA)共聚物进行熔融共混增韧。研究了三种质量比(90/10、80/20和70/30)的聚乳酸/EAA共混物的相形态、力学性能和流变性能。结果表明，EAA的加入在一定程度上提高了聚乳酸的韧性，但在一定程度上降低了其拉伸强度，导致聚乳酸由脆性断裂向延性断裂转变。80/20(w/w)的聚乳酸/EAA共混物具有最大的断裂伸长率(13.93%)和冲击强度(3.18 kJ/m2)，分别是聚乳酸的2.2倍和1.2倍。90/10和80/20LA/EAA共混物呈液滴-基质结构，数均半径为0.30-0.73μm，而70/30共混物为细长的共连续结构，EAA相的半径较大(2.61μm)，且在EAA相中存在聚乳酸液滴。这三种不同相形态的共混物在低频区表现出不同的线性粘弹性特性，通过复数粘度、储能模数、损耗角正切和Cole-Cole图进行了研究。特别的是，80/20的聚乳酸/EAA共混物在其科尔-科尔曲线上显示了两个圆弧。因此，从复粘度虚部图得到了80/20共混物的最长松弛时间，并用Palierne模型计算了聚乳酸与EAA之间的界面张力为4.4mN/m。©2013威利期刊公司J.应用。波兰姆。SCI。2014年，131,40146。
This work aimed to study, for the first time, the melt blending of poly(lactic acid) (PLA) and ethylene acrylic acid (EAA) copolymer by a novel vane extruder to toughen PLA. The phase morphologies, mechanical, and rheological properties of the PLA/EAA blends of three weight ratios (90/10, 80/20, and 70/30) were investigated. The results showed that the addition of EAA improves the toughness of PLA at the expense of the tensile strength to a certain degree and leads the transition from brittle fracture of PLA into ductile fracture. The 80/20 (w/w) PLA/EAA blend presents the maximum elongation at break (13.93%) and impact strength (3.18 kJ/m2), which is 2.2 and 1.2 times as large as those of PLA, respectively. The 90/10 and 80/20 PLA/EAA blends exhibit droplet-matrix morphologies with number average radii of 0.30–0.73 μm, whereas the 70/30 PLA/EAA blend presents an elongated co-continuous structure with large radius (2.61 μm) of EAA phase and there exists PLA droplets in EAA phase. These three blends with different phase morphologies display different characteristic linear viscoelastic properties in the low frequency region, which were investigated in terms of their complex viscosity, storage modulus, loss tangent, and Cole-Cole plots. Specially, the 80/20 PLA/EAA blend presents two circular arcs on its Cole-Cole plot. So, the longest relaxation time of the 80/20 blend was obtained from its complex viscosity imaginary part plot, and the interfacial tension between PLA and EAA, which is 4.4 mN/m, was calculated using the Palierne model. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40146.