Polypropylene/calcium carbonate nanocomposites
Polypropylene/calcium carbonate nanocomposites
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DOI：
10.1016/s0032-3861(02)00120-9
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发表时间：
2002-05-01
期刊：
影响因子：
4.6
通讯作者：
Cheung, YK
中科院分区：
文献类型：
--
作者：
Chan, CM;Wu, JS;Cheung, YK
采用Haake混合机熔融共混法制备了聚丙烯（PP）/碳酸钙纳米复合材料。CaCO 3纳米颗粒的平均初级粒度测量为约44 nm。当填料含量低于9.2体积%时，CaCO 3纳米粒子在PP中的分散性良好。差示扫描量热法（DSC）结果表明，碳酸钙纳米粒子是一个非常有效的成核剂的聚丙烯。拉伸试验表明，纳米复合材料的模量增加了约85010，而极限应力和应变，以及屈服应力和应变没有太大的影响由碳酸钙纳米粒子的存在。拉伸试验的结果可以解释的两个抗衡力的存在下，碳酸钙纳米粒子的增强效果和PP的球晶尺寸的减小。悬臂梁冲击试验表明，在PP中掺入CaCO 3纳米粒子显着增加了约300%的冲击强度。J积分测试表明，缺口断裂韧性显着增加500%。扫描电子显微镜的显微照片显示，PP基体的球晶结构的情况下。此外，DSC结果表明在加入碳酸钙纳米颗粒后存在少量相PP。我们认为，大量的碳酸钙纳米颗粒可以作为应力集中的网站，这可以促进在加载过程中的颗粒-聚合物边界的空化。空蚀可以解除基体的塑性约束，引发基体的大规模塑性变形，从而大大提高材料的断裂韧性。(C)2002爱思唯尔科技有限公司版权所有。
Polypropylene (PP) and calcium carbonate nanocomposites were prepared by melt mixing in a Haake mixer. The average primary particle size of the CaCO3 nanoparticles was measured to be about 44 nm. The dispersion of the CaCO3 nanoparticles in PP was good for filler content below 9.2 vol%. Differential scanning calorimetry (DSC) results indicated that the CaCO3 nanoparticles are a very effective nucleating agent for PP. Tensile tests showed that the modulus of the nanocomposites increased by approximately 85010, while the ultimate stress and strain, as well as yield stress and strain were not much affected by the presence of CaCO3 nanoparticles. The results of the tensile test can be explained by the presence of the two-counter balancing forces-the reinforcing effect of the CaCO3 nanoparticles and the decrease in spherulite size of the PP. Izod impact tests suggested that the incorporation of CaCO3 nanoparticles in PP has significantly increased its impact strength by approximately 300%. J-integral tests showed a dramatic 500% increase in the notched fracture toughness. Micrographs of scanning electron microscopy revealed the absence of spherulitic structure for the PP matrix. In addition, DSC results indicated the presence of a small amount of phase PP after the addition of the calcium carbonate nanoparticles. We believe that the large number of CaCO3 nanoparticles can act as stress concentration sites, which can promote cavitation at the particle-polymer boundaries during loading. The cavitation can release the plastic constraints and trigger mass plastic deformation of the matrix, leading to much improved fracture toughness. (C) 2002 Elsevier Science Ltd. All rights reserved.