乙烯-乙酸乙烯酯共聚物/氢化丁腈橡胶共混物的相态结构和低温性能研究

Morphology and Low Temperature Performance of EVM/HNBR Blends

采用熔融共混法制备乙烯-乙酸乙烯酯共聚物(EVM)/氢化丁腈橡胶(HNBR)共混物,研究其硫化特性、相态结构、动态力学性能、物理性能和低温拉伸性能。结果表明:当EVM/HNBR共混比为70/30时,EVM形成连续相,HNBR形成分散相;随着HNBR用量的增大,HNBR相态由分散相向连续相转变。HNBR的加入可以提高EVM的耐低温性能,当EVM/HNBR共混比为30/70时,共混物-40℃下的低温拉断伸长率可达300%左右。差示扫描量热分析表明,随着HNBR用量的增大,共混物玻璃化温度降低。

The curing characteristics, morphology, dynamic and physical properties and low tern- perature tensile strength of ethylene-vinyl acetate rubber（EVM）/hydrogenated nitrile-butadiene rub-ber（HNBR） blends prepared by melt blending were investigated. The results showed that EVM formed the continuous phase and HNBR was the dispersed phase when the blending ratio of EVM/ HNBR was 70/30. HNBR could become continuous phase with the increase of HNBR mass fraction. The low-temperature resistance of EVM was improved with the addition of HNBR. When the blending ratio of EVM/HNBR was 70/30, the elongation at break at -40 ℃ was around 300%. Differential Scanning Calorimeter analysis also indicated that the glass transition temperature of the blends shifted toward low temperature with increasing HNBR mass fraction.