The inclusion of CaCO3 and kaolin in polyvinyl chloride (PVC) polymer matrices greatly enhances the physical and mechanical properties of the composite. In this study, the effects of kaolin and surface treatment of Ca...The inclusion of CaCO3 and kaolin in polyvinyl chloride (PVC) polymer matrices greatly enhances the physical and mechanical properties of the composite. In this study, the effects of kaolin and surface treatment of CaCO3 and kaolin particles on the microstructure and mechanical properties of PVC composites filled with kaolin particles via melt blending method were studied by means of SEM, tensile, Charpy impact testing, and FTIR. Treated and untreated kao-lin particles were dispersed in matrices of PVC resin at different concentrations up to 30 wt percentage. The tensile strength, elastic modulus, strain to failure and morphology of the resulting composites were measured for various filler loadings. Uniform dispersion of the fillers into the matrix proved to be a critical factor. SEM images revealed that small sized particles were more agglomerated than micron-sized particles and the amount of agglomerates increased with increasing particle content. Silane treated Kaolin-CaCO3/PVC composites had superior tensile and impact strengths to untreated kaolin-CaCO3/PVC composites. The Young’s modulus of all composites increased with increasing particle content up to maximum at 10% filler loading followed by gradually decreasing as content increased.展开更多
This article adopts the double decomposition method, select the appropriate experimental conditions and operation process, respectively add appropriate amount of sodium carboxymethyl cellulose （CMC） as crystal contr...This article adopts the double decomposition method, select the appropriate experimental conditions and operation process, respectively add appropriate amount of sodium carboxymethyl cellulose （CMC） as crystal control agent to study the influence of crystalline of ultrafine calcium carbonate. The experimental results show that the different concentrations of CMC as crystal control agent on the morphology and crystal structure of calcium carbonate have obvious effect, which emerge morphology change from square to spherical, crystalline transition from calcite to aragonite. Thus, the results provide experimental data and theoretical basis for the use of different additives, and provide experimental basis and feasible solution for this kind of reaction.展开更多
【目的】获得超细碳酸钙准确的仿真模型参数,实现超细碳酸钙的可靠仿真研究。【方法】将超细碳酸钙精简为软质球形粒子,使用颗粒接触缩放原理与量纲分析进行颗粒缩放,采用Hertz-Mindlin with JKR接触模型,结合物理实验和离散元软件EDEM...【目的】获得超细碳酸钙准确的仿真模型参数,实现超细碳酸钙的可靠仿真研究。【方法】将超细碳酸钙精简为软质球形粒子,使用颗粒接触缩放原理与量纲分析进行颗粒缩放,采用Hertz-Mindlin with JKR接触模型,结合物理实验和离散元软件EDEM仿真实验对超细碳酸钙的静态和动态休止角进行接触参数标定。首先利用单因素实验排除对静态和动态休止角影响不显著的参数。采用Box-Behnken实验搭建静态和动态的休止角和显著性参数之间的回归模型。将实际测定的静态和动态休止角作为响应值,进而对静态和动态休止角回归模型求解获得最佳的仿真参数组合,并对得到的仿真参数进行物理实验验证。【结果】得到显著性参数的最佳组合为:超细碳酸钙-超细碳酸钙静摩擦系数和滚动摩擦系数为0.36、0.31,超细碳酸钙-不锈钢静摩擦系数和滚动摩擦系数为0.38、0.22,离散元仿真实验所得到的静态动态休止角分别为42.5°和61.3°,与实测值的误差分别为0.96%和1.32%,无明显差异。【结论】参数标定后的接触参数能够应用于超细碳酸钙离散元仿真。展开更多
文摘The inclusion of CaCO3 and kaolin in polyvinyl chloride (PVC) polymer matrices greatly enhances the physical and mechanical properties of the composite. In this study, the effects of kaolin and surface treatment of CaCO3 and kaolin particles on the microstructure and mechanical properties of PVC composites filled with kaolin particles via melt blending method were studied by means of SEM, tensile, Charpy impact testing, and FTIR. Treated and untreated kao-lin particles were dispersed in matrices of PVC resin at different concentrations up to 30 wt percentage. The tensile strength, elastic modulus, strain to failure and morphology of the resulting composites were measured for various filler loadings. Uniform dispersion of the fillers into the matrix proved to be a critical factor. SEM images revealed that small sized particles were more agglomerated than micron-sized particles and the amount of agglomerates increased with increasing particle content. Silane treated Kaolin-CaCO3/PVC composites had superior tensile and impact strengths to untreated kaolin-CaCO3/PVC composites. The Young’s modulus of all composites increased with increasing particle content up to maximum at 10% filler loading followed by gradually decreasing as content increased.
文摘This article adopts the double decomposition method, select the appropriate experimental conditions and operation process, respectively add appropriate amount of sodium carboxymethyl cellulose （CMC） as crystal control agent to study the influence of crystalline of ultrafine calcium carbonate. The experimental results show that the different concentrations of CMC as crystal control agent on the morphology and crystal structure of calcium carbonate have obvious effect, which emerge morphology change from square to spherical, crystalline transition from calcite to aragonite. Thus, the results provide experimental data and theoretical basis for the use of different additives, and provide experimental basis and feasible solution for this kind of reaction.
文摘【目的】获得超细碳酸钙准确的仿真模型参数,实现超细碳酸钙的可靠仿真研究。【方法】将超细碳酸钙精简为软质球形粒子,使用颗粒接触缩放原理与量纲分析进行颗粒缩放,采用Hertz-Mindlin with JKR接触模型,结合物理实验和离散元软件EDEM仿真实验对超细碳酸钙的静态和动态休止角进行接触参数标定。首先利用单因素实验排除对静态和动态休止角影响不显著的参数。采用Box-Behnken实验搭建静态和动态的休止角和显著性参数之间的回归模型。将实际测定的静态和动态休止角作为响应值,进而对静态和动态休止角回归模型求解获得最佳的仿真参数组合,并对得到的仿真参数进行物理实验验证。【结果】得到显著性参数的最佳组合为:超细碳酸钙-超细碳酸钙静摩擦系数和滚动摩擦系数为0.36、0.31,超细碳酸钙-不锈钢静摩擦系数和滚动摩擦系数为0.38、0.22,离散元仿真实验所得到的静态动态休止角分别为42.5°和61.3°,与实测值的误差分别为0.96%和1.32%,无明显差异。【结论】参数标定后的接触参数能够应用于超细碳酸钙离散元仿真。
