Curing and Morphology Studies of Thermosets from Blends of a Main Chain Liquid Crystalline Polyester and Diepoxide/Diamine

✍ Scribed by Werner Mormann; Tomasz Pokropski

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 396 KB
• Volume: 290
• Category: Article
• ISSN: 1438-7492
• DOI: 10.1002/mame.200500029

✦ Synopsis

Abstract

Summary: Blends of the commercial liquid‐crystalline polyester Rodrun LC‐3000 (60–90 wt.‐%) with a bisphenol A‐diglycidyl ether based diepoxide (DOW D.E.R.330) and an aromatic diamine (MCDEA) prepared in a twin‐screw extruder have been compression‐moulded and cured either isothermally at 260 °C or in a temperature ramp between 160 and 230 °C. The blends were investigated with SEM and thermal analysis (DSC, DMTA). Blends with 80% Rodrun and less cured at 260 °C and the blend containing 60% Rodrun cured in a temperature ramp showed macro‐phase separation followed by reaction‐induced micro‐phase separation (RIPS) both in the Rodrun‐rich and in the epoxy‐rich macro‐separated phases. Blends containing 90, 80 and 70% Rodrun moulded at 160 °C and cured in the temperature ramp showed only RIPS and a morphology rather similar to that of the uncured blends that was most likely co‐continuous; the blend with 90% Rodrun cured at 260 °C showed RIPS and a dispersed epoxy phase in a Rodrun matrix. Phase composition has been determined by extraction of the soluble fraction and chemical analysis.

SEM showing the reaction induced micro‐phase separation for sample REA90/10i.

magnified imageSEM showing the reaction induced micro‐phase separation for sample REA90/10i.