辐射改性LDPE/EVA共混物及其超临界CO_2发泡行为的研究

Radiation modified LDPE/EVA blend and its foamiability using supercritical carbon dioxide

用60Coγ射线辐照改性LDPE/EVA共混物,并利用超临界CO2发泡技术制得了微孔LDPE/EVA共混物泡沫。用差示扫描量热仪(DSC)、高级流变扩展系统(ARES)和扫描电镜(SEM)分别对交联LDPE/EVA共混物的熔点、结晶度、粘度以及泡沫的微孔形貌进行了表征。结果表明,辐照处理以后,LDPE/EVA共混物样品的熔点和结晶度略有降低,粘度特性得到改善,可发泡性能提高。共混物吸收剂量为50kGy时,经超临界CO2发泡在105℃和23MPa下制得的泡沫具有较好的泡孔结构。

LDPE/EVA blend were modified by γ-irradiation,and then foamed by using supercritical carbon dioxide as blowing agent. The effect of absorbed dose on melting temperature,crystallization and shearing viscosity of LDPE/EVA blend was characterized by means of differential scanning calorimeter （DSC） and advanced rheology expand system （ARES）.The morphology of the foam was investigated in detail by scanning electron microscopy （SEM）. Experimental results showed that the melting point and the crystallinity of LDPE/EVA blend slightly decreased after γ-irradiation. However,the viscosity and foaming property of the blend were improved than the original blend. At foaming temperature of 105℃ with the saturation pressure of 23 MPa,the optimal absorbed dose for the foaming of the blend was found to be 50 kGy.