不同交联密度体系的原子转移自由基聚合行为和交联结构

Network Structures and Reaction Behavior in the Atom Transfer Radical Polymerization Systems with Different Curing Densities

使用差示扫描量热(DSC)和动态力学分析(DMA)方法研究了甲基丙烯酸酯/二甲基丙烯酸酯原子转移自由基聚合(ATRP)体系交联密度与聚合行为的关系。在低交联密度体系中交联单体用量增加导致聚合速率加快,在高交联密度体系中悬挂双键反应能力成为决定聚合速率的主要因素;微波辐射可以增强悬挂双键的反应能力,促进交联聚合;交联单体用量增加导致交联密度增大,网络均匀性变差。

The relations between reaction behavior and network density in the atom transfer radical polymerization （ATRP） of methacrylate/dimethacrylate were studied by following the kinetic and structural evolution during the polymerization using differential scanning calorimetry （DSC） and dynamic mechanical analysis （DMA）. Polymerization rate increased with the increase of dimethacrylate concentration in the system with lower network densities, while the reactivity of the pendant groups governed the kinetics in the densely crosslinked system. The reactivity of the pendant groups was enhanced by microwave irradiation, which promoted crosslinking. The ATRP with higher dimethacrylate concentration generated polymers with denser networks and poor structural homogeneity.