Origin of Impact Strength in Polycarbonate: I. Effect of Crystallization and Residual Solvent
Origin of Impact Strength in Polycarbonate: I. Effect of Crystallization and Residual Solvent
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聚碳酸酯冲击强度的由来：一、结晶和残留溶剂的影响
DOI：
10.1080/00914037408081923
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
G. Yeh
中科院分区：
文献类型：
--
作者：
M. Wyzgoski;G. Yeh
玻璃态聚碳酸酯的高冲击强度与其过量的自由体积、较大的低温β转变或独特的形态有关。为了确定结晶如何影响自由体积，分子运动和形态，无定形和部分结晶的聚碳酸酯样品已通过特定的体积和动态力学测量，电子显微镜和X-射线衍射技术进行了研究。以前的研究已经给出了相互矛盾的结果，关于结晶的影响，低温β转变低于Tg。我们的研究结果表明，结晶和残留溶剂对β转变产生不同的影响，从而澄清了这一问题。显示结晶降低β损失峰的强度，表明β运动发生在聚合物的“非结晶”区域。溶剂不仅使β峰强度降低，而且使峰最大值向低温移动，导致峰位降低。
Abstract The high impact strength of glassy polycarbonate has been suggested to be related to an excess free volume, a large low temperature beta transition, or a unique morphology. To determine how crystallization affects free volume, molecular motion and morphology, samples of amorphous and partially crystalline polycarbonate have been studied by means of specific volume and dynamic mechanical measurements, electron microscopy and x-ray diffraction techniques. Previous studies have given conflicting results concerning the effect of crystallization on the low temperature beta transition below Tg . Our results clarify this matter by showing that crystallization and residual solvent give different effects on the beta transition. Crystallization is shown to decrease the intensity of the beta loss peak suggesting that the beta motion occurs in the “non-crystalline” regions of the polymer. Solvent not only decreases the beta peak intensity, but also shifts the peak maximum to lower temperatures and causes an ...