The free volume properties of high impact polystyrene ( HIPS)-low density polyethylene ( LDPE) blend have been investigated by means of positron annihilation lifetime spectra ( PALS). 不同组成的高冲聚苯乙烯(HIPS)和低密度聚乙烯(LDPE)共混物的正电子湮没寿命谱被测量,结果表明HIPS和LDPE是不相溶共混物。