Degradation and its temperature dependence of poly(methyl methacrylate)(PMMA) in the blend film of PMMA/SAN were investigated via in-situ X-ray photoelectron spectroscopy(XPS). The results show that thermal degradation of PMMA takes place at 185, 130, 80 ℃ and even room temperature due to the existence of monochromatic X-ray. Furthermore, the degradation rate depends crucially on the experiment temperature.
A series of H-shaped （PS）2PEG（PS）2 block copolymers with different PS chain lengths were prepared. The influence of different confinements active on the crystallization and self-nucleation （SN） behavior of the PEG blocks was investigated by differential scanning calorimetry （DSC）. When the content of the crystalline block was high, a classical SN behavior was obtained. The block copolymer with PEG content of 49% （by weight） showed a classical SN behavior with a narrow self-nucleation domain and had bimodal crystallization exotherms. When the PEG dispersed as separated microdomains in the block copolymer, the self-nucleation domain disappeared and only annealing was observed.
