Prediction of the storage lifetime for PA66 with dynamic mechanical thermal analysis
Xiangyan Meng, Huibao Zheng, Xuerong Wang, Kangwang, Qianqian Wang, Shicheng Li, Suping Zheng, Yunchuan Liu, Yanping Zhou and Kai Yao
Prediction of the storage lifetime (aging time) of polymer is of great significance in the use of materials in electrical equipments. The dynamic mechanical thermal analysis (DMTA) is suitable for predicting the storage lifetime of polymer determined by the change of the molecular structure. The change patterns of loss tangent, the storage modulus and the activation energy of the PA66 (nylon 66) were analyzed with the DMTA, and the critical aging times based on the points of sudden changes in the curves of these properties were 423.0 h, 360.4 h and 315.7 h, separately. After the apparent active energy of the glass transition was calculated with the WLF equation and the functional active energy determined, the storage lifetime of PA66 was calculated with Arrhenius equation as 18.9 a, 16.2 a and 14.2 a, separately. The lifetime predicted with the DMTA were compared with that of the CA method and TPS method, and the result indicates that predicting the storage lifetime of the PA66 with the DMTA is practicable.
Keywords: PA66; storage lifetime; prediction; DMTA