Electrically conductive carbon black (CB) filled in situ microfibrillar poly(ethylene terephthalate) (PET)/polyethylene (PE) composite with a selective CB distribution
Electrically conductive carbon black (CB) filled in situ microfibrillar poly(ethylene terephthalate) (PET)/polyethylene (PE) composite with a selective CB distribution
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DOI：
10.1016/j.polymer.2006.12.026
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发表时间：
2007-01-26
期刊：
影响因子：
4.6
通讯作者：
Li, Zhong-Ming
中科院分区：
文献类型：
--
作者：
Dai, Kun;Xu, Xiang-Bin;Li, Zhong-Ming
在本研究中，试图通过选择性地将CB颗粒定位在PET微纤丝表面，制备一种新型导电炭黑（CB）填充的聚对苯二甲酸乙二醇酯（PET）/聚乙烯（PE）原位微纤丝复合材料，其具有较低的渗滤阈值。首先将CB颗粒与PE基体混合，然后将PET添加到CB/PE复合材料中。随后，CB/PET/PE复合材料经过狭缝模头挤出、热拉伸和淬火工艺，生成原位PET微纤丝，其中CB颗粒同时移动到PET微纤丝的表面。形态观察表明，PET 相形成了清晰的微纤维，并且 CB 颗粒绝大多数集中在 PET 微纤维的表面，这导致了非常低的渗滤阈值，即 3.8 vol%，并且具有良好的导电性。导电网络是通过CB颗粒涂覆的PET微纤维的接触和重叠而构建的。此外，保留在 PE 基体中的炭黑颗粒也有助于导电路径，特别是对于高炭黑负载填充的微纤维复合材料。由于CB颗粒分布的复杂性，该导电复合材料中存在高临界电阻指数t（t = 6.4）。为了揭示CB颗粒从PE迁移到PET的可能性，对混合不同时间的CB/PET/PE复合材料的形态进行了检测。研究发现，根据混合时间，CB 颗粒首先逐渐从 PE 基体迁移到表面，然后迁移到 PET 相的中心。 CB颗粒的优选分布源于多种因素，包括界面张力、粘度、分子极性和混合过程。此外，在CB/PET/PE复合材料的混合过程中，CB颗粒从PE基体迁移到PET相，导致分散相与基体的粘度比和分散相的体积增加，从而产生较大的分散的CB/PET复合相颗粒。 (c) 2006 Elsevier Ltd. 保留所有权利。
In the present study, it was attempted to fabricate a new conductive carbon black (CB) filled poly(ethylene terephthalate) (PET)/polyethylene (PE) in situ microfibrillar composite with a lower percolation threshold through selectively localizing CB particles in the surfaces of the PET microfibrils. The CB particles were first mixed with PE matrix, and then PET was added into CB/PE compound. Subsequently, the CB/PET/PE composite was subjected to a slit die extrusion, hot stretch and quenching process to generate in Situ PET microfibrils, in which CB particles moved to the surfaces of the PET microfibrils simultaneously. The morphological observation showed that the PET phases formed well-defined microfibrils, and CB particles did overwhelminaly localize in the surfaces of the PET microfibrils, which led to a very low percolation threshold, i.e., 3.8 vol%, and a good conductivity. The conductive network was built by the contact and overlapping of the CB particles coated PET microfibrils. In addition, the CB particles remaining in the PE matrix also contributed to the conductive paths, especially for the high CB loading filled microfibrillar composites. Because of the complexity of the distribution of CB particles, a high critical resistance exponent t (t = 6.4) exists in this conductive composite. To reveal the possibility of the migration of CB particles from PE to PET, the morphology of the CB/PET/PE composite mixed for different times was examined. It was found that, depending on the mixing, time, the CB particles gradually migrated from the PE matrix to the surfaces at first, and then to the center of the PET phases. The preferable distribution of CB particles was originated from several factors including interfacial tension, viscosity, molecule polarity, and mixing process. Furthermore, during the mixing process of the CB/PET/PE composite, the migration of CB particles to PET phase from PE matrix led to the increase of both the viscosity ratio of the dispersed phase to the matrix and the volume of the dispersed phases, thus resulting in larger dispersed CB/PET composite phase particles. (c) 2006 Elsevier Ltd. All rights reserved.