상온에서의 충격 흡수특성과 compression set 특성을 향상시키기 위하여 ethylene vinyl acetate copolymer (EVA)와 styrene vinyl isoprene styrene triblock copolymer (SVIS)를 블렌드하여 발포체를 제조하였다. 발포제 및 EVA/SVIS 블렌드비가 발포배율 및 기계적 물성에 미치는 영향을 조사하였다. SVIS 함량이 증가함에 따라 블렌드의 점도는 증가하였고 가교 속도는 감소하였으며, 발포배율은 감소하여 비중은 증가하였다. 발포제 함량 증가, 즉 발포배율 증가에 따른 반발탄성은 변화가 없는 반면에, SVIS 함량 증가에 따라 발포체의 상온에서의 tan ${delta}$ 값은 증가하였으며 따라서 반발 탄성은 감소함을 알 수 있었다. EVA/SVIS 블렌드 발포체에서 SVIS 함량 증가에 따라 가교밀도와 비중이 증가하므로 compression set 값도 낮은 값을 나타내었다.
The foam of ethylene vinyl acetate (EVA)/styrene-vinyl isoprene-styrene triblock copolymer(SVIS) blend was prepared to improve the shock-absorption and compression set characteristics at room temperature. The effects of blowing agent and blend ratio of EVA/SVIS on expansion ratio, cell structure and mechanical properties of the foam were investigated. As the SVIS content increased, the viscosity of blends was increased but the crosslinking rate was slow down, the expansion ratio was decreased. and the specific gravity was increased. At room temperature, the resilience was not affected by increasing the amount of blowing agent. The value of tan ${delta}$ was increased by increasing the amount of SVIS. As a result, the value of compression set was decreased. This is due to the increased values of specific gravity and crosslinking density of the EVA/SVIS foam.
