Electrical and mechanical behavior of carbon black-filled poly(vinyl acetate) latex-based composites

The electrical and mechanical behaviors of carbon black-filled, poly(vinyl acetate) latex-based polymer composites were examined. These composites wer e found to exhibit percolation thresholds in electrical conductivity near 2 vol% carbon black due to their segregated microstructures. Storage modulus and ultimate tensile strength (UTS) both exhibited discontinuities at 10 v ol% carbon black, corresponding to a critical pigment volume concentration. Drying composites at 60 degreesC rather than room temperature produced a h igher percolation threshold and better mechanical properties at carbon blac k loadings above 10 vol% carbon black. A figure of merit was proposed to as sess the balance of electrical conductivity, storage modulus and UTS. The f igure of merit exhibited a peak value at 10 vol% for composites dried at ro om temperature and was shifted to higher carbon black concentrations when c omposites were dried at 60 degreesC.