Foaming behavior of polypropylene/polystyrene blends enhanced by improved interfacial compatibility
作者:翟文涛, 王红英, 余坚*, 董金勇*, 何嘉松.
关键字:blends,microcellular foam,poly(propylene),polystyrene,supercritical
论文来源:期刊
具体来源:Journal of Polymer Science Part B-Polymer Physics, 2008, 46(16): 1641-1651.
发表时间:2008年
A series of polypropylene (PP)/polystyrene (PS) blends were prepared by solvent blending with PS-grafted PP copolymers (PP-g-PS) having different PS graft chain length as compatibilizers. The interfacial compatibility was significantly improved with increasing PS graft chain length until the interface was saturated at PS graft chain length being 3.29 3 103 g/mol. The blends were foamed by using pressure-
quenching process and supercritical CO2 as the blowing agent. The cell preferentially formed at compatibilized interface because of low energy barrier for nucleation. Combining with the increased interfacial area, the compatibilized interface lead to the foams with increased cell density compared to the incompatibilized one. The increase in interfacial compatibility also decreased the escape of gas, held more gas for cell growth, and facilitated the increase in expansion ratio of PP/PS blend foams.