木塑复合材料润滑剂性能的转矩流变性评价

木塑复合材料挤出工艺中,使用润滑剂可以提高生产效率,改善制品表面性能.在转速、混炼器温度、加料量等优化参数条件下用转矩流变仪研究了不同木粉质量分数时润滑剂SWP201对木粉/高密度聚乙烯(WF/HDPE)复合材料熔体转矩流变行为的影响.结果表明:加入界面相容剂马来酸酐接枝聚乙烯(MAPE)与否,质量分数2%的SWP201能够明显降低相应对照复合材料熔体的平衡转矩(Ma)和熔体温度(T);木粉质量分数在0%～6O%范围内增加时,复合熔体的Ma和T呈明显的增加趋势,稳态时熔体温度(T)与混炼器温度(T0)之差△T从11℃增加到18℃左右,△T值反映不同体系的相对摩擦发热作用.Ma与体系的黏度相关.流变行为不同的样品Ma和△T都不同,一般来说Ma较大的△T也较大.转矩流变方法可用于高填充木塑复合体系的流变性和润滑剂性能评价.

Torque Rheological Evaluation of Lubricant Effectiveness for Wood Thermoplastic Composites

Lubricant can facilitate wood plastic composites（WPCs） extrusion outputs with improved surface appearance.The torque rheometer was used to investigate the effects of lubricant SWP201 on the torque rheological behavior of wood flour/HDPE composite（WF/HDPE） melts at varied wood flour content with and without compatibilizer maleic anhydride grafted polyethylene（MAPE）,by using experimentally optimized test parameters such as rotor speed,test temperature,and to facilitate comparing samples with different rheological properties.The results indicated that the equilibrium torque（Ma） and melt temperature（T） of composites decreased obviously by adding a loading of 2% SWP201 compared with control sample with and without MAPE,respectively.Ma and T of composites increased obviously with wood flour content in the tested range of 0%~60%,with temperature difference（△T） between mixer and melt from 11 ℃ to about 18 ℃.The values of △T can characterize the relative quantity of the shear heating during compounding procedure of composites.The torque of the composites is considered to be associated with the melt viscosity of the composites.Two samples which differ much in their viscosity result in rheograms with both torque and melt temperature curves being different.The sample with bigger measured Ma often has higher △T value.Torque rheometry is reliable on evaluation flow performance of highly filled composite melts and effectiveness of WPCs additives.