THERMAL-BEHAVIOR OF ALPHA-NYLON-12
THERMAL-BEHAVIOR OF ALPHA-NYLON-12
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DOI：
10.1002/pol.1980.180180619
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发表时间：
1980-01-01
影响因子：
--
通讯作者：
KASAI, N
中科院分区：
文献类型：
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作者：
ISHIKAWA, T;NAGAI, S;KASAI, N
采用差示扫描量热法研究了苯酚-乙醇混合物浇铸的α尼龙-12薄膜的热行为。通过X射线衍射分析多晶型。γ型在热谱图中显示出单一的吸热熔融峰，而α型显示出双峰。α和γ相混合的样品在同一位置出现双峰，峰面积比随两种相含量的变化而变化。即使对于α样品，γ峰的出现也是由于α形式熔化后再结晶成γ形式。α尼龙-12的熔点为ca。173°C，比γ型低6-7°。一旦α或γ样品被熔化然后冷却，其加热热谱图在主峰出现之前显示出一个小峰。小峰似乎是由于在冷却期间形成的不完整和/或较小的微晶。低于α尼龙-12熔点的热处理可有效地将α型转化为γ型，可能是通过熔融再结晶过程。
The thermal behavior of α nylon‐12 film cast from a phenol‐ethanol mixture has been studied by differential scanning calorimetry. Polymorphism has been analyzed by x‐ray diffraction. The γ form exhibits a single endothermic melting peak in the thermogram, whereas the α form exhibits double peaks. Samples with mixed α and γ forms show double peaks at the same positions and the area ratio changes in accordance with the amounts of the two forms. The appearance of the γ peak, even for the α sample, is explained by recrystallization to the γ form after melting of the α form. The melting point of α nylon‐12 is ca. 173°C, which is lower by 6–7° than that of the γ form. Once the α or γ sample has been melted and then cooled, its heating thermogram shows a small peak before the appearance of the main peak. The small peak seems to be due to incomplete and/or smaller crystallites formed during cooling. Heat treatment below the melting point of α nylon‐12 is effective in transforming the α form to the γ form, probably via a melt‐recrystallization process.