Effects of the addition of small amounts of a thermotropic liquid crystalline polymer on the processing characteristics of polyphenylene oxide–polyamide alloys

✍ Scribed by Vera Ruggiero; Domenico Acierno

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 702 KB
• Volume: 26
• Category: Article
• ISSN: 0730-6679
• DOI: 10.1002/adv.20089

✦ Synopsis

Abstract

The possibility of improving the processing characteristics of a high‐viscosity engineering polymer alloy (PPO‐PA6,6) was explored through the addition of small amounts of a thermotropic liquid crystalline polymer (LCP). The thermal and rheological characteristics were examined for LCP contents up to 5 wt%. Inclusion of even a small amount of LCP (1 wt%) has resulted in a substantial decrease in the melt viscosity (∼50%) and in the possible lowering of the processing temperature of the PPO–PA alloy. Numerical simulation and experimental tests for the injection molding of a fairly complex component have shown that cavity filling occurs more rapidly when small amounts of LCP are added to the blend. Together with morphological examinations, these results have confirmed that LCP is thoroughly dispersed in the blend and acts as a true viscosity depressant, rather than behaving as an external lubricant. The resulting improvements in processing characteristics were also evident from the increase in the onset degradation temperature and the reduction in thermal expansion coefficient of the blends. © 2007 Wiley Periodicals, Inc. Adv Polym Techn 26:109–120, 2007; Published online in Wiley InterScience www.interscience.wiley.com). DOI 10.1002/adv.20089