核壳聚合物粒子对环氧树脂热膨胀系数的影响

采用核壳聚合物(Core-Shell Polymer,CSP)粒子改性环氧树脂,通过红外光谱、热力学分析和扫描电镜研究了CSP粒子对环氧树脂基体热膨胀系数(CTE)的影响。结果表明:CSP粒子壳材料分子链中的羰基在环氧树脂固化过程中可与环氧分子侧链上的羟基形成氢键作用,从而加强了核壳聚合物粒子与环氧树脂的界面作用。随着CSP粒子质量分数的增加,改性环氧树脂基体的玻璃化转变温度呈下降趋势;相对于纯环氧树脂,改性环氧树脂在玻璃化转变温度下的CTE呈现先下降后上升的趋势,添加质量分数为0.5%的CSP后,其CTE值降低了12.88%。但在玻璃化转变温度上的热膨胀系数均高于纯环氧树脂。

Effect of core-shell polymer particles on the coefficient of thermal expansion of epoxy resin

The epoxy resins were modified by core-shell polymer(CSP) particles.The effect of CSP on the coefficient of thermal expansion(CTE) of modified epoxy resins was investigated by infrared spectroscopy,thermal mechanical analysis and scanning electron microscopy.The results showed that hydrogen bond was formed between C= =O of CSP particle shell and — OH of DGEBA epoxy resin side chain during the curing pocess,thereby strengthening the interface role of core-shell polymer particles and epoxy matrix.The glass transition temperatures of CSP particles modified epoxy resin were decreased and CTE values of modified resin below the Tg range were decreased,then increased compared with that of neat epoxy resins with the increasing of CSP content.The CTE of the resins with 0.5% CSP was decreased by 12.88%.But the CTE values of modified resins were all higher than that of neat epoxy resins above the Tg range.