【摘要】 用毛细管流变仪研究了双峰中密度聚乙烯(BMDPE)及其与高压聚乙烯(LDPE)共混物熔体的流变行为。讨论了共混物的组成、剪切应力、剪切速率及温度对熔体流变行为的影响和挤出膨胀比,测定了不同配比熔体的非牛顿指数(n),熔融指数(MI)。测定了共混物的屈服应力、断裂应力和断裂伸长率。证明共混物的强度随双峰中密度聚乙烯含量的增加而提高,为BMDPE的加工和使用提供了依据。更多还原

【Abstract】 Melts rheological behavior of bimodal medium density polyethylene(BMDPE)/lowdensity polyethylene(LDPE) blends was studied. Influences of composition of the blends, shear ratio and shear stress on melt apparent viscosity were discussed. NonNewtonian index (n), melting index (MI) and swell ratio of the blends with different proportions were measured. Processability of BMDPE was apparently improved by LDPE. Conventional yield stress, breaking stress and breaking extensibility of the blends with different proportions were also measured. It shows that mechanical properties of the blends are improved with BMDPE content increasement.更多还原