Effect of heating on the structure of carbon fiber polyphenylenesulfide-matrix composite, as studied by electrical resistance measurement

摘要

Heating and cooling were found to affect the structure of carbon fiber polyphenylenesulfide-matrix composites, as shown by their effects on the DC electrical resistance of the composite in the fiber direction. Matrix now during first heating above Tg and thermal stress buildup during cooling in any thermal cycle caused the resistance to increase, whereas isothermal crystallization at 180 degrees C caused the resistance to decrease. Thermal stress buildup was reversible upon thermal cycling. Prior annealing at 180 degrees C diminished the matrix flow because of improved fiber-matrix bond, and it increased the matrix crystallinity. Annealing at 180 degrees C for 15 h or more was sufficient to eliminate the matrix flow. [References: 7]