长链支化聚丙烯的制备及其熔体流变性能的研究

PREPARATION AND MELT RHEOLOGICAL PROPERTIES OF LONG CHAIN BRANCHED POLYPROPYLENE BY REACTIVE EXTRUSION

在过氧化物引发剂和季戊四醇三丙烯酸酯存在下,利用反应挤出法制备了长链支化聚丙烯(LCB-PP)。采用熔体流动速率(MFR)仪、旋转流变仪和熔体强度测试仪对纯聚丙烯(PP)及其改性PP进行测试与表征。讨论了不同的过氧化物引发剂对改性PP流变性能的影响。结果表明,采用过氧化苯甲酰时,改性PP具有较高的熔体强度、较低的MFR,并且在低频处储能模量增大。同时发现,随温度的升高,改性PP的熔体强度逐渐降低,但升高到一定温度后,熔体强度的变化不明显。

Long chain branched polypropylene was achieved by reactive extrusion in the presence of pentaerythritol triacrylate （PETA） and peroxide. Different testing techniques, such as MFR, rotational rheometer and melt strength, were used to characterized the initial PP and modified PP, respectively. Moreover, the influence of the types of peroxide on the rheological properties of modified PP was evaluated. The results showed that the modified PP used peroxide BPO had higher melt strength, lower MFR and higher storage modulus at the low frequency. At the same time, the melt strength of modified PP decreased with the increase of temperature.