The effect of moisture on the dielectric behavior of poly(vinyl acetate)–natural rubber blend

Abstract

AbstractDynamic dielectric analysis was used to analyze the miscibility of poly(vinyl acetate) and natural rubber and the effect of moisture on the dielectric properties of the polymer blend. Two separate dielectric relaxations were observed within the temperature range studied. The high‐temperature relaxation was a result of the glass transition of poly(vinyl acetate), whereas the low‐temperature relaxation was attributed to that of natural rubber. The peak temperatures of ε″ of the high‐temperature relaxation decreased with increasing aging time, while the magnitudes of the ε″ peaks increased with increasing days of aging. The peak temperatures of ε″ of the low‐temperature relaxation stayed constant, while the magnitudes of the ε″ peaks increased with increasing days of aging. This indicates that both polymers are responsible for the sorption of moisture; however, water is an effective plasticizer only for poly(vinyl acetate). Anomalous increases in the magnitudes of ε″, especially in the low frequency sides, of the Argand diagrams were explained by Maxwell–Wagner–Sillar (MWS) polarization at component interfaces. The oscillator strength, relaxation time, and the two distribution parameters, A and B, calculated from the skewed circular are equation, were affected with days of aging.