使用旋转流变仪系统分析了聚丙烯/乙烯-辛烯共聚物共混物熔体黏弹性能对外部条件如剪切、温度和动态剪切频率的响应情况并分析PP/POE共混物的熔体相容性.随POE含量的增加(基体相由PP改为POE),PP/POE共混物的流变行为出现分界.不同温度下的黏度曲线形状类似,非牛顿性指数n基本保持不变.PP/POE共混体系的零剪切黏度呈现负偏差,符合广义对数加和法则.在末端区(0.005~0.050Hz),共混物的Ig G'-lgω斜率明显与PP的有偏差且Han曲线在高频下出现了随温度变化的情形,表明PP/POE熔体不相容.在密炼机加工过程,即温度在190~250℃,PP质量分数在50%~95%之间时,共混体系处于相分离状态.
The rheological behavior and melting miscibility of binary blends consisting of polypropylene (PP) and poly (ethylene-1-octene) (POE) have been systematically investigated with a Stresstech rheometer in the molten state. With the increase of POE content,the rheological behaviors of the samples change accordingly. The viscosity curve is similar at different temperatures,and the non-Newtonian index n remanins the same. The general log mixing can well describe the zero shear viscosity of the blends. In the terminal zone (0.005-0.050 Hz), the slopes of double logarithm curve of the dynamic storage modulus versus frequency of PP and PP/POE blends are different,which indicates the phase separation of the blends. Han curves of PP/POE(80/20) show that at low and medium frequency regions the curve of dynamic storage modulus versus dynamic loss modulus is independent of temperature yet at high frequency regions the curve changes with temperature which proves that PP/POE blends are not miscible. During the mixing(190-250 ℃), the blends are in the state of phase seperation when the mass fraction of PP is 50%-95%.