PLA/半水硫酸钙复合材料结晶性能和流变性能研究

Investigation of Crystallization Property and Rheological Properties of PLA/CSH Composites

采用共混法制备了聚乳酸/半水硫酸钙(PLA/CSH)复合材料,研究了CSH用量对PLA/CSH复合材料结晶性能和流变性能的影响。结果表明:CSH对PLA基体具有明显的异相成核作用,提高了PLA的熔融温度;PLA/CSH复合材料的表观黏度(η_a)随着剪切速率和温度的提高逐渐降低,随着CSH用量的增加先提高后降低;共混体系的非牛顿指数(n)随着温度的提高而增大,随着CSH用量的增加先增大后减小;复合材料熔体的黏流活化能(ΔE_η)随着剪切速率的提高而降低,随着CSH用量的增加先降低后提高。

PLA/CSH composites were prepared by blending methods with Poly（lactic acid） and calcium sulfate hemihydrate. The effects of the addition of CSH on crystallization and mechanical properties of PLA/CSH composites were studied. The results show that CSH has obvious nucleating effect on PLA matrix, improve the melting temperature of PLA; the melt apparent viscosity（ηa） of PLA/CSH composites decreases with the increase of the shear rate and the temperature; the ηa of PLA/CSH composites decreases first and then increases with the increase of the content of CSH; the Non-Newtonian index（n） of PLA/CSH composites goes up with the increase of temperature, and then n value increases first and then decreases with the increase of CSH content; The viscous flow activation energy decreases with the increase of shear rate, and it shows a downward as a whole with the increase of the content of CSH.