Near-infrared SERS Study of the Adsorption of a-PMMA Dip-coated onto Silver Mirror Substrate

The interface between a-PMMA thin film and silver mirror substrate was investigated using surface-enhanced Raman scattering (SERS). It is found that the molecular chain axis of a-PMMA tends to parallel the substrate in the interface. When the sample is annealed at different temperatures, some interesting changes appear in the SERS spectra. The spectra differences and their transition are due to the surface geometry change of the ester group.

高压下无规聚甲基丙烯酸甲酯的玻璃化转变

采用PVT -10 0分析仪测试了无规聚甲基丙烯酸甲酯 (a -PMMA)在 3 0～ 180℃ ,2 0～ 180MPa下的压力 -体积 -温度 (PVT)曲线。与常压下玻璃化转变是某一点不同 ,高压下a -PMMA的玻璃化出现一个反常的转变区 ,并且随着压力增加 ,该转变区逐渐加宽。PVT实验后 ,a -PMMA的数均和重均摩尔质量均明显下降 ;由DSC测试的Tg和TGA测定的Td 也明显降低 。