This work was concerned with how the crystallization temperature of a thermotropic liquid crystalline polymer (TLCP) was lowered when blended with a second TLCP, with both TLCPs believed to be composed of various ratios of terephthalic acid, 4-hydroxybenzoic acid (HBA), hydroquinone, and hydroquinone derivatives. Specifically, HX6000, with a melting temperature of 332°C, was melt blended with HX8000, with a melting temperature of 272°C. Measuring the complex viscosities of the melt blends as they were cooled showed that a linear relationship between composition and solidification temperature existed. Studying the blends using differential scanning calorimetry (DSC) demonstrated that the crystallization temperature was lowered by addition of HX8000, as well as by using faster cooling rates. Dynamic mechanical analysis revealed that the storage and loss moduli decreased with the addition of HX8000 and the moduli declined sharply at lower temperatures relative to neat HX6000. Additional testing was performed to help understand this behavior, with the results suggesting that the TLCPs reacted with one another when the test samples were injection molded.
Посилання на статтю:
The crystallization behavior of blends of thermotropic liquid crystalline polymers / M.A. McLeod, D.G. Baird // Polymer. – 1999. – N 40. – P. 3743–3752.