Abstract A method of investigating the relationship between morphological evolution and mechanical properties of blends prepared by Micro injection moulding through regulating the process conditions was presented in this paper. The microstructure and microscopic mechanical properties of polycarbonate/poly (ethylene terephthalate) (PC/PET) microparts prepared by micro injection moulding were investigated with respect to the effects of the injection velocity. The PC/PET microparts exhibited typical “skin–core” morphology. Thickness of the skin layer is greater than that of the core layer near the gate of micropart. With an increase in the injection velocity, the core layer became thicker. It was detected that the PET microdomains were selectively located in the core layer in preference to the shear layer with high injection velocity. In addition, the degree of orientation for main chain and pendant group in the PC/PET molecular chains increased first and then decreased with an increase in the injection velocity. Nanoindentation testing showed that the modulus decreased along the flow direction and increased with an increase in the injection velocity, except at very high values. Among the different layers, the highly oriented shear layer had the highest indentation modulus.

中文翻译：

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注射速度对微注射成型聚碳酸酯/聚对苯二甲酸乙二醇酯共混物结构和机械性能的影响

摘要 本文提出了一种通过调节工艺条件研究微注射成型共混物的形态演变与力学性能关系的方法。研究了通过微注射成型制备的聚碳酸酯/聚对苯二甲酸乙二醇酯 (PC/PET) 微零件的微观结构和显微机械性能，以及注射速度的影响。PC/PET 微型部件表现出典型的“皮芯”形态。在微件浇口附近，表层的厚度大于芯层的厚度。随着注射速度的增加，芯层变厚。检测到 PET 微区选择性地位于核心层，而不是具有高注射速度的剪切层。此外，PC/PET分子链中主链和侧基的取向度随着注射速度的增加先增大后减小。纳米压痕测试表明，模量沿流动方向降低，并随着注射速度的增加而增加，但非常高的值除外。在不同的层中，高度取向的剪切层具有最高的压痕模量。