超细微化有机磷酸盐成核剂对聚丙烯性能的影响*

摘要

Ultra-fine organic phosphate nucleating agent was prepared by supercritical fluid technology,the effects of ultra-fine organic phosphate nucleating agents on the crystallization behavior and mechanical properties of polypropylene(PP) were investigated. The morphologies of organic phosphate nucleating agents were analyzed by scanning electron microscopy,and the effects of organic phosphate nucleating agents before or after the ultra-fine processing on the crystallinity,the crystallization temperatures and grain sizes of PP were analyzed by differential scanning calorimetry and polarizing microscope. The experimental results show that after ultra-fine processing the morphologies of nucleating agents is changed. The particle sizes of organic phosphate nucleating agents became smaller and the dispersion is better. In case of adding 0.2 phr organic phosphate nucleating agents NA-11,NA-13 before or after the ultra-fine processing,all the crystallization peak temperatures of PP are increased. Meanwhile, the highest temperature is up to 131.7 ℃,the crystallinity significantly increases,the crystallization growth rates go up while the sizes of spherulite reduce significantly,and the crystallization nucleation effects are more apparent by the ultra-fine processing.Both the tensile strength,flexural properties and the transparency of PP are improved by nucleating agent. The tensile strength,flexural properties and transparency are further improved by the ultra-fine nucleating agents,the bending elastic modulus is improved by 48.4%comparing with pure PP,the smallest haze is 15.3%.%采用超临界流体技术制备超细微化有机磷酸盐成核剂，研究了超细微化有机磷酸盐成核剂对聚丙烯(PP)结晶行为及力学性能的影响。采用扫描电子显微镜分析成核剂的微观形貌，通过差示扫描量热法和偏光显微镜分析超细微化处理前后有机磷酸盐成核剂对PP结晶度、结晶温度以及晶粒尺寸的影响。结果表明，经超细微化处理，成核剂微观形貌发生变化，粒径变小，分散更均匀。分别添加0.2份超细微化处理前后的成核剂NA-11，NA-13，均可使PP的结晶峰温度提高，最高达到131.7℃，结晶度显著增加，同时结晶速率提高，球晶尺寸大幅下降，成核剂经超细微化处理后，其结晶成核效果更明显。成核剂可明显提高PP的拉伸强度、弯曲性能和透明性。成核剂超细微化处理后，PP的拉伸、弯曲性能和透明性进一步提高，弯曲弹性模量较纯PP提高48.4%，最小雾度为15.3%。