The use of dynamic mechanical thermal analysis technique for determining an uneven distribution of precipitated silica in CPE/NR blends
The use of dynamic mechanical thermal analysis technique for determining an uneven distribution of precipitated silica in CPE/NR blends
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使用动态机械热分析技术确定 CPE/NR 共混物中沉淀二氧化硅的不均匀分布
DOI：
10.1016/j.polymertesting.2008.06.010
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发表时间：
2008
期刊：
影响因子：
5.1
通讯作者：
C. Sirisinha
中科院分区：
文献类型：
--
作者：
Pakpum Phewphong;P. Sae;C. Sirisinha
沉淀白炭黑一般用作浅色产品的非黑色补强填料。与炭黑相比，白炭黑的使用存在许多问题，尤其是白炭黑的分散性和分布性较差。在白炭黑填充的CPE/NR共混物中，白炭黑在共混物各相中的不均匀分布主要是由于白炭黑表面的硅醇基团和CPE主链上的氯原子之间存在强烈的填料-聚合物相互作用所致。为了研究填料在聚合物共混物中的不均匀分布，可以利用阻尼性的变化来计算共混物中局部分布的二氧化硅的量。结果表明，在白炭黑用量较小的情况下，由于天然橡胶相粘度较低和白炭黑-CPE相互作用较强的抵消作用，白炭黑的分布比较均匀。随着SiO_2负载量的增加，SiO_2-CPE相互作用占优势，导致SiO_2优先迁移到CPE相中。硅烷偶联剂的加入降低了高二氧化硅负载量下二氧化硅的不均匀分布。3-硫氰丙基三乙氧基硅烷(Si-264)比二(3-三乙氧基硅丙基)四磺烷(Si-69)具有更好的润湿性和硅醇失活效率。由动态力学性能确定的二氧化硅不均匀分布与共混物的相形态很好地吻合。
Precipitated silica is generally used as non-black reinforcing filler for light colored products. Compared with carbon black, the use of silica is subject to many problems, particularly poor silica dispersion and distribution. In silica filled CPE/NR blends, the uneven distribution of silica in each phase of the blend occurs mainly due to strong filler–polymer interaction between silanol groups on the silica surfaces and chlorine atoms on the CPE backbone. In order to investigate the uneven filler distribution in polymer blends, changes in damping behavior could be used to calculate the amount of silica localizing in each phase of the blends. The results reveal that, with small loading of silica, an even silica distribution is observed due to the counter-balancing effects of relatively low viscosity of the NR phase and strong silica–CPE interaction. As silica loading increases, the effect of strong silica–CPE interaction becomes dominant, leading to preferential migration of silica to the CPE phase. The uneven silica distribution at high silica loading is found to be reduced by addition of silane coupling agents. The effect of 3-thiocyanatopropyl triethoxy silane (Si-264) is more pronounced than bis-(3-triethoxysilylpropyl) tetrasulfane (Si-69) due to the superior wettability and, hence, the silanol deactivation efficiency. The determination of uneven silica distribution by dynamic mechanical properties is in good agreement with the phase morphology of blends.