Change of Strength by Heat Treatment of Laminated Composite Prepared from Kevlar Cloth and Furan Resin

Abstract

Change of strength by heat treatment of laminated composite prepared from Kevlar cloth and furfuryl alcohol resin (furan resin) was studied by bending test below 600 °C. The laminated composite containing 39% fiber by volume showed almost the same value of bending strength as the matrix furan resin, and the effect of fiber cloth was recognized in the heat treatment temperature range from 200 to 500 °C. The laminated composite showed its own feature on the load vs. deflection curve. That is, a sudden flexural fracture did not occur below 400 °C as shown in Fig. 8c. On the heat-treated samples, the relationship, σ ∝ ρⁿ was recognized between the bending strength (σ) and the bulk density (ρ). Also, a linear relation was obtained, when the results were plotted with bending strength (σ_||) as abscissa against elastic modulus (E_||) as ordinate, but no linear relation could not be observed by plotting of E_⊥ and σ_⊥.