Polypropylene (PP) resin and a thermotropic liquid crystal polymer (LCP) were mixed and coextruded on a screw extruder. The LCP was found to exist in fibril form above a PP/LCP (wt/wt) ratio of 100/5 and a PP/LCP ratio of 100/15 the LCP existed in a network structure. For the as-spun fibre, both the initial modulus and the yield stress increased with the increase in the LCP concentration. In the drawn fibres, however, the LCP fibrils were found to be split into short fragments. A two-stage drawing process was used in order to reduce the extent of fracture of the LCP fibrils. The drawn fibres were found to contain more long fibrils from the two-stage process and as a result, there were significant increases in both the tensile strength and initial modulus of the two-stage drawn fibres.
Посилання на статтю:
Fibres from polypropylene and liquid crystal polymer (LCP) blends: 1. Effect of LCP concentration / Y. Qin, D. L. Brydon, R. R. Mather* and R. H. Wardman // Polymer. – 1993. – Vol 34. – P. 1196-1201.