Blends of two thermotropic liquid crystalline polymers: The influence of reactions during injection molding on the phase structure and the mechanical behavior

• Published in: Polymer engineering and science Vol. 41; no. 7; pp. 1115 - 1123
• Main Authors: Vallejo, F. J., Eguiazábal, J. I., Nazábal, J.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.07.2001; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Analysis; Applied sciences; Chemical reactions; Exact sciences and technology; Injection molding; Machinery and processing; Moulding compound preparation. Mixing; Plastics; Polymer industry, paints, wood; Polymer liquid crystals; Technology of polymers; United States; Mixing; Polymer blends; Property composition relationship; Thermotropic state; Naphthoate(hydroxy) copolymer; Mechanical properties; Benzoate(hydroxy) copolymer; Transesterification; Esteramide copolymer; Experimental study; Ester copolymer; Liquid crystal polymers; Aromatic copolymer; Injection molding; Growth from melt
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.10812

Blends of two different thermotropic liquid crystalline polymers, poly(p‐hydroxy benzoic acid‐co‐2, 6‐hydroxy naphthoic acid), VA, and poly(p‐hydroxybenzoic acid‐co‐terephthalic acid‐co‐aminophenol), VB, were obtained by direct injection molding throughout the full composition range. The blends were almost fully immiscible apart from a low degree of reaction. This, as well as the nature of the blends, probably influenced their mechanical properties. Enhanced properties were obtained both in the modulus of elasticity and in the tensile strength, at all the compositions studied, with absolute maxima at VB contents between 50% and 75%. These synergisms were mainly due to a greater orientation of the components in the blends than in the pure components.