摘要
用调制式差示扫描量热法研究了聚丙烯(PP)升温过程熔融特性与线性升温速率(β)、温度调制振幅(A_T)和阅制周期(p)的相关性。实验结果表明,在低β时,总热流部分PP熔融呈现双峰;β加快时,呈现单熔融峰。随β加快,不可逆热流部分熔融热(△H)增加;可逆热流部分出现明显的放热峰。随p延长,总热流部分和不可逆热流部分的熔融峰温(T_p)基本不变,起始熔融温度(T_(on))降低;但△H前者不变,后者增加;可逆热流部分从吸热变成放热,放热峰温移向高温。总热流和不可逆热流部分的T_p和T_(on)不受A_T的影响,但随A_T增大△H前者不变,后者降低。
The dependences of melting characteristics of polypropylene (PP) on linear heating rate (β), modulated period (p) and modulated amplitude (AT) were studied by modulated differential scanning calorimetry The results show that there exist double peaks in melting process of PP at low β, but only a single peak appears as β is speeded up in total heat flow curves. As β rises, the melting heat (△H) goes up in irreversible heat flow curves, and an obvious exothermic peak occurs in reversible heat flow curves. When p is prolonged, the peak temperatures of melting (Tp) in both the total and the irreversible heat flow curves basically remain unchanged, but the temperatures of onset melting (Ton) lower. Although the △H is not varied in the total heat flow curves, it indeed increases in the irreversible heat flow curves. The endothermic behavior in the reversible heat flow curve is transformed into exothermic behavior and furthermore, the resultant exothermic peak shifts toward high temperature direction. The Tp and Ton in both the total and the irreversible heat flow curves are not dependent on A T. However, with increasing A T, the △H does not vary in the total heat flow curves but rises in the irreversible heat flow curves.
出处
《合成树脂及塑料》
CAS
2003年第5期8-11,共4页
China Synthetic Resin and Plastics
基金
广东省自然科学基金团队研究(20003038)
重点项目(021731)
广东省科技攻关项目(A1070207)
广州市科技攻关项目(Z3-D2011)
广东省高校"千百十"工程人才培养基金(Q02016)
