NASCENT STRUCTURES DURING POLYMERIZATION OF ETHYLENE .2. CALORIMETRIC STUDY
NASCENT STRUCTURES DURING POLYMERIZATION OF ETHYLENE .2. CALORIMETRIC STUDY
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DOI：
10.1007/bf01381688
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发表时间：
1974-01-01
影响因子：
2.4
通讯作者：
MARCHESSAULT, RH
中科院分区：
文献类型：
--
作者：
CHANZY, HD;BONJOUR, E;MARCHESSAULT, RH
研究了新生或“生长时”聚乙烯的热行为。对各种高分子量样品的熔化曲线的分析表明，最大熔点通常比在没有外部变形的情况下从熔体或溶液结晶的样品对应的熔点更尖锐和更高。熔点随着聚合时间的延长而增加，聚合几分钟的样品至少达到 412 °K (139 °C)。这通常伴随着 415°K (142°C) 左右更高的次最高温度的出现，这对应于具有过热特性的长链结晶材料。这些特征可以通过在新生样品的聚合和结晶过程中连续变形起作用的方案来解释。
The thermal behaviour of nascent or “as grown” polyethylene was studied. The analysis of the melting curves of various high molecular weight samples show that the maximum melting points are usually sharper and higher than those corresponding to samples crystallized from the melt or solution in absence of external deformation. The melting points increase with polymerization time and reach at least 412 °K (139 °C) for samples polymerized for few minutes. This usually goes along with the appearance of a higher submaximum around 415°K (142°C) which corresponds to extended chain crystalline material having superheating properties. Such features are explained in terms of a scheme where continuous deformation is operative during polymerization and crystallization of the nascent samples.