高填充碳酸钙母料的流变行为

Rheological Behavior of Masterbatch with High Loadings of Calcium Carbonate

采用平板式旋转流变仪研究了碳酸钙粒径及填充量、分散树脂种类及用量、温度对高填充碳酸钙母料流变性能的影响。研究发现,填充母料的流变曲线出现两个"剪切变稀"区域,分别与低剪切速率下填料与树脂间的结合破坏和高剪切速率下分子链缠结破坏及链段取向有关;母料的零剪切黏度远高于线形低密度聚乙烯(PE-LLD),且随碳酸钙粒径细化和含量的增加而迅速增大;填充母料"剪切变稀"行为比 PE-LLD 更加明显,导致在10~2～10~3 s^(-1)剪切速率范围内母料与纯树脂的表观黏度比较接近;高剪切速率下碳酸钙粒径对表观黏度影响不大,添加分散树脂明显降低了填充母料的表观黏度;母料的流动活化能为25.7 kJ/mol,与 PE-LLD 的相近。

Effects of particle size and content of calcium carbonate, the type and dosage of dispersant resin, and processing temperature on the rheological behavior of the heavily loaded calcium carbonate masterbatch were investigated using a rotating rheometer with parallel plate geometry. Two ＂shear thinning＂ regions were observed from the rheological curves, with one in the low shear rate region being attributed to the collapse of interface combination between the filler and resin, and the other being related to the dis-entanglement and orientation of polymer chains in the high shear rate range. The zero shear rate viscosity of the masterbatch was much larger than that of PE-LLD and increased rapidly with increasing filler content and/or decreasing particle size. The apparent viscosity in high shear rate region showed little change with filler size, but dramatically decreased with the addition of dispersant resins. The flow activation energy of the masterbatch was 25.7 kJ/mol, close to that of PE-LLD.