Shear-enhanced crystallization of a thermoplastic polyimide derived from 3,3 ',4,4 '-oxydiphthalic dianhydride and 4,4 '-oxydianiline
Shear-enhanced crystallization of a thermoplastic polyimide derived from 3,3 ',4,4 '-oxydiphthalic dianhydride and 4,4 '-oxydianiline
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由3,3,4,4-氧联二邻苯二甲酸二酐和4,4-氧二苯胺衍生的热塑性聚酰亚胺的剪切增强结晶
DOI：
10.1002/polb.21243
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Wei Jiang
中科院分区：
文献类型：
--
作者：
Guiyan Zhao;Min Zhang;Yongfeng Men;M. Ding;Wei Jiang
研究了连续剪切对由3,3',4,4'-氧二苯二酐（3,3',4,4'-ODPA）和4,4-氧二苯胺（ODA）合成的非晶态芳香族聚酰亚胺（PI）结晶的影响。在260℃时，剪切速率或剪切时间的增加导致结晶度的增加。事实上，增加剪切速率也可以加速结晶行为。此外，在较高的温度下，长时间或高速率剪切试样出现了新的熔化峰。结晶行为的增强似乎与晶体厚度的增加直接相关。特别地，研究了剪切温度的影响，结果表明，在260℃时，PI的结晶对剪切更为敏感，这比PI的玻璃化转变温度（250℃）高10℃。提出了连续剪切对PI聚合物结晶影响的可能机理。
The aim of this work is to investigate the effect of consecutive shear on the crystallization of an amorphous aromatic polyimide (PI) derived from 3,3',4,4'oxydiphthalic dianhydride (3,3',4,4'-ODPA) and 4,4-oxydianiline (ODA). At 260 degrees C, the increase of shear rate or shear time leads to the increase of crystallinity. Indeed, increasing shear rate can also accelerate the crystallization behavior. Moreover, it was found that a new melting peak appeared at higher temperature for long time or high rate sheared sample. The enhancement of crystallization behavior appears directly linked to the increase of crystal thickness. Particularly, the effect of shear temperature was investigated, and the results revealed that the crystallization of the PI was more sensitive to shear at 260 degrees C, which was 10 degrees above the glass transition temperature (250 degrees C) of the PI. Possible mechanism was proposed to illustrate the effect of consecutive shear on the crystallization of the PI polymer.