碳酸钙高填充聚乙烯醇复合材料热塑加工性能研究

Study on Thermal Processability of Highly Filled PVC /CaCO_3 Composites

采用分子复合和增塑,以水、多元醇和含酰胺基团化合物组成复配增塑剂,通过热塑加工制备了碳酸钙(CaCO3)高填充聚乙烯醇(PVA)复合材料,采用差示扫描量热仪(DSC)、热重分析(TG)、高压毛细管流变仪等研究了复合材料的热性能、流变性能,探讨了复合材料中增塑剂的迁移率及其对制品尺寸稳定性的影响。结果表明,通过分子复合和增塑后,改性PVA及PVA/CaCO3复合材料获得较宽热塑加工窗口,当CaCO3含量为70%时热塑加工窗口达85.5℃;PVA/CaCO3复合材料的熔体为假塑性流体,其黏度满足传统挤出或注塑加工的黏度需要;随环境湿度增加,复合材料中增塑剂迁移率增加,CaCO3可抑制复合材料中增塑剂的迁移,一定程度上提高了复合材料的尺寸稳定性。

According to the molecular complexation and plasticization,highly filled PVA/CaCO3composites were prepared successfully by thermal processing using water,polyols and amide compound as mixed plasticizer.The thermal properties,rheological properties and the dimensional stability of PVA/CaCO3 composites were studied by differential scanning calorimetry （DSC）,thermogravimetric analysis （TGA）,high pressure capillary rheometer,etc.The results showed that the modified PVA and PVA/CaCO3composites had wider thermal processing window through molecular complexation and plasticization.The thermal processing window was 85.5 ℃ when CaCO3 content was 70 wt％.PVA/CaCO3 composite was pseudoplastic fluid,and its viscosity met the need of traditional extrusion or injection molding.The plasticizer migration ratio increased along with the humidity,while CaCO3 could reduce the plasticizer migration,which improved the dimensional stability of PVA/CaCO 3 composites.