电缆用高阻燃耐热软质PVC的制备及性能研究

以软质PVC为基体,选用氢氧化铝-氢氧化镁(ATH/MDH)为复配阻燃剂、硼酸锌(ZB)为阻燃协效剂及钙锌材料为复合热稳定剂(Ca-Zn),通过共混法对PVC进行改性,制备PVC/ATH/MDH、PVC/ATH/MDH/ZB及PVC/ATH/MDH/ZB/Ca-Zn等软质PVC复合电缆料。分析3种电缆料的阻燃性能、拉伸性能及热稳定性。结果表明:相较纯软质PVC,PVC/ATH/MDH与PVC/ATH/MDH/ZB的阻燃性能提高,拉伸性能显著下降,且热稳定性改善不明显。而PVC/ATH/MDH/ZB/Ca-Zn的阻燃性能显著提升,与纯软质PVC相比,其极限氧指数(LOI)增加34.90%,烟密度等级下降29.50%,复合材料的炭层更连续且致密;PVC/ATH/MDH/ZB/Ca-Zn的拉伸强度和断裂伸长率分别提高1.78%和2.48%。Ca-Zn的添加提高软质PVC的残炭率,热稳定性增强。PVC/ATH/MDH/ZB/Ca-Zn的综合性能最佳。

Preparation and Properties of High Flame Retardancy and Heat Resistant Fexible PVC for Cable

With fexible PVC as the matrix, aluminum hydroxide-magnesium hydroxide(ATH/MDH) was selected as the compound flame retardant, zinc borate(ZB) as the flame retardant synergist and calcium-zinc material as the compound thermal stabilizer(Ca-Zn). PVC was modified by blending method to prepare PVC/ATH/MDH, PVC/ATH/MDH/ZB and PVC/ATH/MDH/ZB/Ca-Zn fexible PVC composite cable materials. The flame retardancy, tensile properties and thermal stability of three kinds of cable materials were analyzed. The results show that compared with pure fexible PVC, the flame retardancy of PVC/ATH/MDH and PVC/ATH/MDH/ZB is improved, the tensile properties of PVC/ATH/MDH and PVC/ATH/MDH/ZB are significantly decreased, and the thermal stability is not significantly improved. The flame retardancy of PVC/ATH/MDH/ZB/Ca-Zn composites are significantly improved. Compared with pure fexible PVC, the LOI of PVC/ATH/MDH/ZB/Ca-Zn composites is increased by 34.90%, the smoke density grade of PVC/ATH/MDH/ZB/Ca-Zn is decreased by 29.50%, and the carbon layer of the composites is more continuous and dense. The tensile strength and elongation at break of PVC/ATH/MDH/ZB/Ca-Zn is increased by 1.78% and 2.48%, respectively. The addition of Ca-Zn increases the carbon residue rate of fexible PVC and the thermal stability is enhanced. PVC/ATH/MDH/ZB/Ca-Zn has the best comprehensive performance.