Chain Length Effects on Crystal Formation in Vinylidene Fluoride Oligomers
Chain Length Effects on Crystal Formation in Vinylidene Fluoride Oligomers
复制标题
链长对偏二氟乙烯低聚物晶体形成的影响
DOI：
10.1295/polymj.30.659
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发表时间：
1998
期刊：
影响因子：
2.8
通讯作者：
N. Okui
中科院分区：
文献类型：
--
作者：
Herman;S. Umemoto;T. Kikutani;N. Okui
研究了偏氟乙烯（VDF）低聚物的α、β和γ晶型随分子链长度的变化。采用调聚法制备了VDF低聚物，并通过真空气相沉积对低聚物进行了分级。将分级分离的低聚物从熔体中结晶。采用红外光谱、X射线衍射、差示扫描量热法对VDF齐聚物的晶型进行了表征。聚合度（N）小于10时为β型，聚合度（N）在10 ~ 16时为α型，聚合度（N）大于16时为γ型。分子链长度对VDF低聚物晶型的影响可能与β型分子链上空间位阻沿着的构象能变化以及α和γ型从熔体中结晶行为的差异有关。
Crystal modifications in vinylidene fluoride (VDF) oligomers, such as α, β, and γ forms, were studied as a function of the molecular chain length. VDF oligomers were prepared by a telomerization method and the oligomers were fractionated by vacuum vapor deposition. The fractionated oligomers were crystallized from the melt. The crystal forms in VDF oligomers were characterized by IR, X-ray, and DSC methods. The β form was found in the degree of polymerization (N) less than 10, the α form consisted of N ranging from 10 to 16 and the γ form was observed in N above 16. The effect of molecular chain length on the crystal forms in VDF oligomers could be associated with change in the conformational energy accompanying the steric hindrance along the molecular chain for the β form and differences in the crystallization behavior from the melt for the α and γ forms.