Research On Morphology And Formation Mechanism Of UHMW-PE Microporous Materials' Microstructure

As a new type of functional material based on Ultra High Molecular Weight Polyethylene (UHMW-PE), UHMW-PE microporous material has been used in a wide variety of fields as a promising functional material. But presently the research on microporous materials, especially on UHMW-PE microporous material in China is in a technically backward situation. Upon this, Taking UHMW-PE microporous separator, one of typical functional material products as an instance, all the studies in the paper are focused on how to develop through a certain Moulding process microporous products which can meet the requirements of performance characteristics, and are accordingly of instructive significance on inland industrial production and quality control.In this paper, the thermodynamic mechanism of TIPS (thermally induced phase separation) method is concisely analyzed and by employing the phase diagram of the binary system --UHMW-PE and its solvents, the effects of phase separation process, solvent system and cooling-rate are summarized. Based on the research mentioned above, the processing procedure on TIPS method of UHMW-PE separator has been studied experimentally, and then the reasonable technical parameters in moulding process and formulation of the material system are determined. A random fractal model used to describe microstructure of UHMW-PE separator is established, and electron microscopic image analysis with computer is used to study on the fractal nature of microporous material, then consequently, not only the fractal characteristic of microporous material has been proved, but also thisspecial fractal aggregation can be described quantitatively by the determination of the fractal dimension. The mensuration of specimens' microstructure parameters through varieties of methods and the characteristics of microporous material are analyzed. The relation between the three factors of the microporous material, moulding process, microstructure and performance characteristics is comprehensively investigated, the characteristics of microstructure are quantitatively described, and subsequently a tentative of discovering the experiential law between processing and performance is carried out.