Formation of oriented β‐transcrystals induced by self‐assembly of nucleating agent and its micropores formation during uniaxial stretching. Issue 3 (6th May 2020) - Yang, Yu
Abstract: The β‐nucleated isotactic polypropylene (β‐iPP) cast films containing networks of self‐assembled nucleating agent (NA) was prepared under the specific processing field in this work. It was found that oriented β‐transcrystals (β‐TCs) formed by crystallizing on the needle‐like agglomerates of self‐assembled NAs. From the results, the microporous membranes with high porosity were obtained by uniaxial stretching the cast films consisted of β‐TCs and the micropores morphology was analogous to that of the separation of row‐nucleated lamellae. With the analysis of mechanism of pores formation, the oriented lamellae on β‐TCs can play a similar role to the row‐nucleated lamellae, presenting another possibility of crystalline morphology to prepare microporous membranes with uniaxial stretching. This work found another suitable crystalline morphology differed from row‐nucleated lamellae, that is, β‐TCs, to fabricate PP microporous membranes through uniaxial stretching. Moreover, it provided a great perspective to establish the relationship between the crystalline and final membranes performance, which helped us to conduct further research on the crystallographic structure of microporous membranes. Abstract : The β‐nucleated isotactic polypropylene cast films containing oriented β‐transcrystals induced by the self‐assembled nucleating agent were prepared under the specific processing field. The results showed that the microporous membranes with high porosity were obtained by uniaxial stretching the cast films consisted of β‐transcrystals, and the micropores morphology was analogous to that of the separation of row‐nucleated lamellae. This work provides a great perspective to establish the relationship between the crystalline and final membranes performance, which enables further research on the crystallographic structure of microporous membranes.