AbstractDynamic mechanical studies of ethylene vinyl acetate rubber indicated the presence of different transitions: the α‐transition or glass‐rubber transition temperature (Tg) at −17°C, the γ‐transition around −60 to −70°C observed as a shoulder, and the γ‐transition in the temperature region of −127 to −135°C, apart from a high‐temperature transition (T1,1) at +69°C. The α‐transition temperature did not shift its position with incorporation of silica filler, but there was gradual sequential lowering of tan δ peak values atTgwith increase in filler loading. Such sequential dependence of tan δ values on filler incorporation was not observed in the cases of β‐ and γ‐transitions. TheT1,1transition was found to be less prominent in the presence of filler, particularly at high concentration. Treatment of the filler with a silane coupling agent caused a shift in the α‐transition temperature to higher temperature by about 4°C. Studies on dynamic mechanical properties under isothermal conditions have shown that the coupling agent caused a breakdown of silica agglomerates during mixing. An increase in frequency caused a shift of tan δ peak positions in the α‐ and γ‐transition regions toward higher temperature. Although frequency did not have a significant effect on the tan δ value at the α‐transition, increase in frequency caused sequential lowering of tan δ value at the α‐transition. increase in frequency caused sequential lowering of tan δ value at the γ‐transition. In the high‐temperature region, theT1,1peak exhibited by the gum compound gradully disa
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