C-IL-010-模压法微孔发泡PET和PC片材的制备及性能-管蓉

管蓉，李应林，肖兆新，刘娟

湖北大学化学化工学院，武汉，430062

关键词：模压法，微孔，泡孔结构，机理

微孔发泡材料以其独特的结构性能，近二十年来发展十分迅速，然而常规的微孔发泡方法如挤出法或注射法都难以制备出薄形工程塑料微孔发泡片材。本文创新性地应用模压法在聚合物高弹态区成功地制备了聚对苯二甲酸乙二醇酯（PET）和聚碳酸酯（PC）薄型微孔发泡片材。该方法具有制备工艺流程简单、

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操作容易、成型周期短、费用低廉等优点，因而有望快速实现工业化生产。 通过改变发泡时间、发泡压力、模压机温度、以及发泡剂浓度等加工条件，制备了一系列不同泡孔尺寸、泡孔密度的PET和PC微孔发泡片材。采用光学显微镜(OM)和场发射扫描电镜(FESEM)表征了泡孔结构和形态，探索了加工条件对泡孔结构的影响；研究了结晶型PET和无定型PC微孔发泡片材泡孔形态的效应；同时通过拉伸实验测定了微孔发泡片材的力学性能，对其电性能也进行了一定的研究。研究结果表明，不同发泡片材的类别和性质是决定泡孔形态大小的主要因素之一；在同一种发泡片材中，发泡时间和发泡压力对PET和PC泡孔的结构影响显著；结晶型聚合物与无定型聚合物微孔发泡后的泡孔形态与尺寸差异较大。通过对不同加工条件下微孔发泡PET和PC片材结构性能的研究，以及发泡气体在PET 和PC基材中的扩散吸收行为，探索了模压法微孔发泡的机理。同时，通过改变基材的厚度、结晶度和增塑程度，进一步深入探讨了模压法微孔发泡的成型加工特点。

参考文献：

[1]Guan R, Wang B, Lu D, J Appl Polym Sci, 2003, 88:1956-1962

[2]Guan R, Wang B, Lu D, Fang Q, Xiang B, J Appl Polym Sci, 2004, 93:1698-1704

[3]Xiang B, Guan R, Fang Q, Xiao Z, Jiang Y, J Appl Polym Sci, 2006, 99:1760-1766 Preparation and Property of Microcellular PET and PC Sheets by

Compression Molding*

∗本课题得到国家自然科学基金资助（50473026）Rong Guan, Yinglin Li, Zhaoxin Xiao, Juan Liu

College of Chemistry & Chemical Engineering, Hubei University, Wuhan 430062 Abstract：In this paper, an innovative method was developed to microcellularly process the thin poly(ethylene terephthalate) (PET) and Polycarbonate (PC) sheets in the viscoelastic state by compression molding, which are difficult to process by conventional microcellular foam methods.A series of microcellular PET and PC sheets with different cell sizes and cell densities were prepared by changing the foaming time, the foaming pressure, the temperature of the compression molding and the blowing agent content. The effects of processing parameters on the microcellular structure, mechanical, electrical and morphology were investigated. The results show that the property of the foaming material is one of the main factors, which determined the microcellular morphology. The cell morphology of the semi-crystalline polymer is different from that of the amorphous polymer. For the same kind of foaming plastic matrix, the foaming time and the foaming pressure have a significant effect on the microcellular structure of the PET and PC sheets. The mechanism of foaming was probed from the research on the foaming structure and properties and the gas diffusion in the PET and PC sheets. In addition, the features of microcellularly processing by compression molding were further explored by changing the sheet thickness, crystallinity and plasticization of the foamed polymer.

Keywords: Compressing molding, Microcellular, Microcellular structure, Mechanism