Evolution of peroxide-induced thermomechanical degradation of polypropylene along the extruder
Evolution of peroxide-induced thermomechanical degradation of polypropylene along the extruder
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DOI：
10.1002/app.13476
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发表时间：
2004-02-15
影响因子：
3
通讯作者：
Covas, JA
中科院分区：
文献类型：
--
作者：
Machado, AV;Maia, JM;Covas, JA
报道了在同向双螺杆挤出机中，在不同操作条件下，过氧化氢诱导聚丙烯降解的实验研究。在没有和有不同浓度的过氧化氢的情况下进行跑步。通过在线流变学测量和在相同位置采集的样品的相对分子质量的测定，表征了沿挤出机的化学反应的演变。结果表明，过氧化氢浓度和加工条件与改性材料的流变性能和分子结构之间存在着一定的关系。断链分布函数的概念阐明了PP的热机械降解机理，它是通过断链进行的，依赖于螺杆元件施加的应力水平、温度和吸氢剂的浓度。(C)2003年威利期刊公司。
An experimental study of the peroxide-induced degradation of polypropylene in a corotating twin screw extruder, operating under various conditions, was reported. Runs were performed without and with peroxide in different concentrations. The evolution of the chemical reactions along the extruder was characterized by on-line rheological measurements and by determination of the molecular weight of samples collected at the same locations. The results evidenced the relationships between peroxide concentration and processing conditions with rheological properties and molecular structure of the modified materials. The concept of chain-scission distribution function elucidated the mechanisms involved in the thermomechanical degradation of PP, which is by chain scission and is dependent on the level of stress imposed by the screw elements, temperature, and concentration of hydrogen-abstracting agents. (C) 2003 Wiley Periodicals, Inc.