Bulk crystallization of poly(aryl ether ether ketone) (PEEK)
Bulk crystallization of poly(aryl ether ether ketone) (PEEK)
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DOI：
10.1002/pen.10457
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发表时间：
1996-03-01
影响因子：
3.2
通讯作者：
Phillips, PJ
中科院分区：
文献类型：
--
作者：
MedellinRodriguez, FJ;Phillips, PJ
同时测量透射偏振光强度并通过偏振光学显微镜记录结晶现象解决了有关聚芳醚醚酮（PEEK）整体结晶行为的一些争议。通过分离成核和生长步骤来研究块体结晶过程。 Avrami 图显示了三个特征范围。据观察，低结晶时间下的第一斜率与球晶的大量异质成核和/或局部有序促进的初级成核相关。随后强度第二次逐渐递减，呈现对数趋势。它代表至少三个并行机制的混合。这些与初级球晶结晶过程的结束有关，并且在很大程度上与零星成核球晶以较低速率成核和生长有关。此外，二次结晶对出现的透射光也有一些贡献。整个有核球晶群继续生长到撞击点，这大致标志着第三个区域的开始。最后一个区域的斜率低于第一个区域，并且具有指数趋势，反映了长时间的二次结晶。讨论了成核和生长过程的一般特征。
Concurrent measurements of transmitted polarized light intensity and recording of the phenomenon of crystallization through polarized optical microscopy have resolved some of the controversies on the bulk crystallization behavior of poly(aryl ether ether ketone) (PEEK). The process of bulk crystallization was studied through the separation of the nucleation and growth steps. Avrami plots have shown three characteristic ranges. It was observed that a first slope at low crystallization times is associated with massive heterogeneous nucleation and/or local-order-promoted primary nucleation of spherulitic crystals. A second gradual decrement in intensity follows, showing a logarithmic tendency. It represents a mixture of at least three parallel mechanisms. These are associated with the end of the process of crystallization of the primary spherulites and in large proportion the nucleation and growth, at lower rates, of sporadically nucleated spherulites. In addition, there is some contribution from secondary crystallization to the transmitted light emerging. The whole group of nucleated spherulites continue growing up to the point of impingement, which loosely marks the beginning of the third region. This last region with lower slope than the first one and an exponential tendency reflects secondary crystallization at long times. The general characteristics of the processes of nucleation and growth are discussed.