Wen Xiufang

Analysis of most probable mechanism functions and thermal degradation kinetics of n-phenylmaleimide-styrene-maleic copolymers

The thermal degradation kinetics of N-phenylmaleimide-styrene-maleic (NSMA) anhydride copolymers was analysed by a non-isothermal kinetic method. Kinetic parameters were obtained using integral and differential methods, and the most probable mechanism functions and kinetic compensation effects were discussed. The activation energy E for the thermal degradation of NSMA was 211.34kJ/mol according to the Flynn-Wall-Ozawa method and the thermal degradation was a first-order chemical reaction. A recommended rate expression for the thermal degradation reaction of NSMA was d α d t = A e − E R T ( 1 − α ) (where α is the conversion, t is time, R is the gas constant, T is the temperature and A is the pre-exponential factor), and the mathematical expressions of compensation effects for the integral and differential methods were lnA=-1.8037+0.1749E and lnA=-2.1974+0.1741E respectively.

Manufacturing and characteristics of copper clad laminates based on glass cloth and polytetrafluoroethylene

This study concerned the manufacture of copper clad laminates using glass cloth/pol ytetrafluoroethylene(PTFE), and the effects of silane treatment on the flexural strength and morphology of the resulting prepregs. About 40 wt% glass cloth in PTFE gave the highest flexural strength. The adhesion to copper was greatest when the glass cloth content was 20 wt% in the prepregs. Finally, the prediction of the dielectric properties was discussed.