丙烯酸和苯乙烯改性PP/PS结晶与熔融行为

制备了苯乙烯（St）、St与丙烯酸（AA）混合物、丙烯酸接枝聚丙烯（PP-g-AA）改性聚丙烯／聚苯乙烯（PP／PS）共混物以及AA，St改性PP（原位形成PP／PS共混物）。用差示扫描量热仪（DSC）研究了3种改性方法对共混物中PP结晶与熔融行为的影响。结果表明，PS对PP的结晶与熔融温度影响不大，PP-g-AA则提高共混物中PP的结晶温度。St以及St与AA混合单体对PP／PS中PP结晶温度影响不大，但AA改性提高PP／PS中PP结晶温度。St加入PP导致PP结晶温度下降，St与AA混合单体原位聚合则提高PP的结晶温度。改性对共混物中PP的熔融温度影响不大，但是熔融峰形与结晶温度高低有关。红外光谱证实St与AA混合单体改性PP中有PP-g-AA形成，但改性共混物中没有PP-g-AA形成。

Crystallization and Melting Behavior of PP/PS Blends Modified by Acrylic Acid and Styrene

PP/PS blends modified by PP-g-AA or reactive monomer,such as acrylic acid (AA)and styrene(St)were prepared.Crystallization and melting behavior were investiga- ted by DSC.The results indicate that addition of PS has little influence on the crystallization temperature of PP.Addition of PP-g-AA can increase significantly the crystallization tem- perature of PP in the blends.Although addition of St or AA/St comonomer hardly influences the crystallization temperature of PP in the blends,an increase in the crystallization tempera- ture of PP in the blends is observed by addition of AA.St added into PP causes fall of crys- tallization temperature of PP,and St and AA added into PP cause rise of crystallization tem- perature of PP.All blends show no remarkable variety in melting temperature,but the shapes of melting peak depend upon the crystallization temperature of PP in the blends.IR results indicate that addition of AA and St into PP results in the formation of PP-g-AA,but no PP-g-AA is formed in PP/PS blends modified by AA and St.