Phase separation in benzoxazine/epoxy resin blending systems
Phase separation in benzoxazine/epoxy resin blending systems
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DOI：
10.1038/pj.2012.179
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发表时间：
2013-06
期刊：
影响因子：
2.8
通讯作者：
P. Zhao;Qian Zhou;Xin Liu;Rongqi Zhu;Q. Ran;Yi Gu
中科院分区：
文献类型：
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作者：
P. Zhao;Qian Zhou;Xin Liu;Rongqi Zhu;Q. Ran;Yi Gu
在苯并恶嗪（BZ）/环氧树脂（ER）共混体系中，通过控制聚合顺序原位增大动态不对称性是获得相分离结构的一种有效方法。本文采用模型组分研究了BZ/ER共混体系中可能发生的反应。结果表明，BZ树脂一旦聚合生成酚羟基（OH），BZ与ER树脂之间的共聚反应就不可避免，这对BZ/ER体系的相分离不利。如果ER先于BZ发生共聚反应，则BZ与ER之间的共聚反应将因酚羟基的缺乏而受到抑制，从而增大ER与BZ之间的动力学不对称性，这两者都有利于相分离。在下面的研究中，使用一系列具有不同分子量（Mn）的ER树脂来研究BZ/ER系统中相分离的可能性。浊度观察、动态力学分析和扫描电镜实验表明，当ER的Mn ≥ 4370 g mol-1时，BZ树脂的聚合会发生相分离，并随ER含量的变化而呈现不同的形貌。
Enlarging dynamic asymmetry in situ by controlling the polymerization sequence is known to be a good way to obtain phase separation structures in benzoxazine (BZ)/epoxy resin (ER) blending systems. In this paper, the possible reactions in BZ/ER blends were studied using model components. The results indicated that once phenolic hydroxyl groups (OH) were produced by the polymerization of BZ resin, the copolymerization between BZ and ER resin was unavoidable, which was unfavorable for the phase separation of the BZ/ER system. If ER could polymerize before BZ, the copolymerization between BZ and ER is expected to be suppressed by the lack of phenolic OH, and the dynamic asymmetry between ER and BZ could thus be enlarged, both of which are favorable for phase separation. In the following studies, a series of ER resins having different molecular weights (Mn) were used to study the possibility of phase separation in the BZ/ER systems. The turbidity observation, dynamic mechanical analysis and scanning election microscope experiments indicated that if the Mn of ER⩾ 4370 g mol− 1, phase separation could take place with the polymerization of BZ resin and different morphologies could be observed by varying the ER content.