화학공학소재연구정보센터
Polymer Engineering and Science, Vol.39, No.5, 953-962, 1999
Thermal analysis of Vectra B950 liquid crystal polymer
The melting and crystallization behavior of Vectra(tm) B950, a random liquid crystalline copoly(ester amide), was studied by differential scanning calorimetry (DSC). Nonisothermal experiments showed the existence of some interesting and peculiar transition behavior, which may depend on the crystallization conditions (cooling rate). In isothermal experiments, both the thermal and crystallization behavior have been studied as functions of annealing temperature and annealing time. Different thermal behaviors were observed, indicating the possibility of multiple states of mesophase aggregation. In addition, the thermal decomposition of Vectra B950 was also studied by TGA-FTIR in both nitrogen and air environments. A single-stage decomposition process was found when heating in nitrogen atmosphere, and the decomposition is due to the ester linkage rupture. A double-stage decomposition process was found when heating in air, and the decompositions are mainly due to the ester linkage rupture for the first decomposition step and the oxidative reaction for the second decomposition step. Annealing slightly changes the decomposition composition occurring in the early stage of thermal degradation.