Abstract
In this study, the thermal oxidative degradation behavior of thermotropic liquid crystal copolyesters P-BPAFx containing 2.5-10 mol% bisphenol AF unit were evaluated by thermogravimetric analysis (TGA) technique under air atmosphere and the degradation activation energy (E) was obtained from Kissinger and Kissinger-Akahira-Sunose (KAS) method. The degradation behavior of copolyester are strongly dependent on the molar percentage of BPAF unit. Results showed that the E values obtained by the two methods increase first and then decrease slightly with increasing the BPAF unit and follow the order P-BPAF5.0< P-BPAF10<P-BPAF2.5, indicating P-BPAF2.5 has good thermal stability. The reason for this phenomenon was discussed in detail in the text.
Publisher
Trans Tech Publications, Ltd.
Reference7 articles.
1. Dutta, D., et al., Polymer blends containing liquid crystals: A Review. Polym. Eng. Sci. 30(17) (1990) 1005-1018.
2. Wei, P., et al., The influence of bisphenol AF unit on thermal behavior of thermotropic liquid crystal copolyesters. Thermochim. Acta. 586(0) (2014) 45-51.
3. Wei, P., et al., Aromatic liquid crystalline copolyesters with low Tm and high Tg: Synthesis, characterization, and properties. J. Appl. Polym. Sci. (2014) DOI: 10. 1002/app. 40487.
4. Kissinger, H.E., Reaction Kinetics in Differential Thermal Analysis. Anal. Chem. 29(11) (1957) 1702-1706.
5. Kissinger, H.E., Variation of peak temperature with heating rate in differential thermal analysis. J. Res. Natl. Bur. Stand. 57(1956) 217-221.