Study of the effect of organic clay on the shear‐induced crystallization of high‐density polyethylene through dynamic‐packing injection molding
Study of the effect of organic clay on the shear‐induced crystallization of high‐density polyethylene through dynamic‐packing injection molding
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DOI：
10.1002/pi.2899
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发表时间：
2010-12
影响因子：
3.2
通讯作者：
C. Deng;Xueqin Gao;Zhanchun Chen;Shan Xue;K. Shen
中科院分区：
文献类型：
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作者：
C. Deng;Xueqin Gao;Zhanchun Chen;Shan Xue;K. Shen
在纳米复合体系中，有机纳米粒子作为非均相成核剂对聚合物基体的结晶有很大的影响，在剪切流动条件下，这种影响会增强。利用自制的动态保压注射成型装置，研究了有机粘土对高密度聚乙烯（HDPE）剪切诱导结晶过程的影响。采用差示扫描量热仪（DSC）、广角X射线衍射仪（WAXD）和扫描电镜（SEM）对HDPE/粘土纳米复合材料注射成型的流动诱导结晶结构进行了表征。结果表明，采用DPIM法制备的HDPE/粘土纳米复合材料具有较高的结晶度和较厚的晶面，这有助于材料力学性能的提高。DSC结果清楚地表明，在动态HDPE/粘土纳米复合材料样品中实现约16%的结晶度的增加，与传统的未填充的HDPE样品相比。WAXD证实动态HDPE/粘土纳米复合材料样品在（110）和（200）晶面处具有最大晶粒尺寸，分别为335和305。SEM图像表明，在动态HDPE/粘土样品的结晶结构的排列略有改变相比，使用相同的工艺参数制备的未填充的HDPE样品。结果表明，在剪切流动条件下，有机粘土有利于提高HDPE/粘土纳米复合体系的结晶度和晶粒尺寸。同时，有机粘土对HDPE/粘土纳米复合体系的结晶结构的排列影响不大，在动态复合体系中仍能形成有序有序排列的层状结构。版权所有© 2010化学工业协会
Organic nanoparticles as heterogeneous nucleators have a great effect on the crystallization of polymer matrices in nanocomposite systems, and the effect will be enhanced under shear flow. A home-made dynamic-packing injection molding (DPIM) device was developed to explore the effect of organic clay on the shear-induced crystallization of high-density polyethylene (HDPE). Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM) were used to characterize the flow-induced crystalline structure of HDPE/clay nanocomposite injection moldings. It was found that higher crystallinity and thicker crystal planes which contribute to the improvement of mechanical properties were achieved in HDPE/clay nanocomposite samples prepared by DPIM. DSC results clearly showed that an increase of about 16% in crystallinity was achieved in dynamic HDPE/clay nanocomposite samples compared with traditional unfilled HDPE samples. WAXD confirmed that dynamic HDPE/clay nanocomposite samples had maximum crystal sizes at the (110) and (200) planes of 335 and 305 A, respectively. SEM images indicated that the arrangement of crystalline structures in dynamic HDPE/clay samples was altered slightly compared with unfilled HDPE samples prepared using the same processing parameters. The results showed that organic clay was beneficial for increasing crystallinity and crystal size in the HDPE/clay nanocomposite system under shear flow. Meanwhile the arrangement of crystalline structures was insignificantly affected by the organic clay, and the preferred regular arrangement of lamellae could still be formed in the dynamic HDPE/clay nanocomposite system. Copyright © 2010 Society of Chemical Industry