Main‐chain side‐chain liquid crystal polymer blends for improved physical properties

Abstract

Previous work has demonstrated that compatible blends of main‐chain liquid crystal polymers (LCP) with side‐chain LCP's can be prepared. The present work was carried out to extend the scope and application of this finding to liquid crystal polyesters, similar to commercially available LCP's and to demonstrate the effect of the blend composition upon the physical and mechanical properties. A series of melt‐processable main‐chain polyesters was prepared as well as a series of acrylic polymers and copolymers which possess a side‐chain mesogenic unit, similar to that of the main‐chain LCP's. While the results of the blending studies of these high molecular weight materials were somewhat ambiguous as to compatibility, there are strong indications that the presence of the side‐chain mesogen containing polymers does result in an improvement in the overall mechanical properties of the main‐chain LCP.

An entropy-driven ring-opening metathesis polymerization approach towards main-chain liquid crystalline polymers

“…3,4 Taking advantage of their rigid mesogenic backbone structures, MCLCP materials compared with SCLCPs, usually possess higher mechanical strengths, higher glass phase transition temperatures, and higher LC-to-isotropic phase transition temperatures. 5 MCLCPs with such unique properties have achieved success in many commercial applications, for example, Kevlar ( poly( paraphenylene terephthalamide)) as a typical MCLCP, 6,7 has been widely used in protective gear and reinforcing composite materials. To date, the known synthetic methods of MCLCPs have been rather limited.…”

Reinforcing properties of poly(trimethyleneterephthalate) by a thermotropic liquid crystal polymer

“…The dispersion of TLCP in the matrix and the adhesion force between matrix and TLCP used as an additive are more important than any other factors in the polymer‐reinforcing system . To increase interfacial adhesion and compatibility of the polymer blend, several methods have been attempted as follows; it blended a TLCP block/graft‐copolymer in which it includes the matrix polymer moiety in the copolymer structure or a TLCP as a compatibilizer in which it has the similar molecular structure with the matrix polymer for increasing the interfacial adhesion and compatibility . Besides, the method that was intended to improve interfacial adhesion with matrix polymer while the side chain of TLCP acts as a kind of solvent‐like materials in the blends .…”