邻苯二甲酸氢钾对聚氯乙烯结构和性能的影响

Effect of Potassium Hydrogen Phthalate on Structure and Macroproperties of Poly(Vinyl Chloride)

以邻苯二甲酸氢钾为添加剂,通过差示扫描量热分析,广角X-射线衍射分析,扫描电镜和电子万能实验机研究了其不同含量对聚氯乙烯(PVC)的晶体结构、微观形态和力学性能的影响.研究结果表明:当邻苯二甲酸氢钾的含量为3 w.t.%时,PVC的结晶度和晶粒尺寸增大,材料微观上形成了“三维网络”结构,使其宏观机械性能较纯PVC增大;但随着邻苯二甲酸氢钾含量的继续增大,PVC的结晶度和晶粒尺寸降低,微观上无网络结构生成而是形成了多孔的结构,并且孔径和孔的平面密度随着邻苯二甲酸氢钾的增多而增大,导致孔穴间基体厚度降低,不利于应力传递,使材料的力学性能显著降低.

The influences of the content of potassium hydrogen phthalate on crystal structure, micromorphology and mechanical properties of polyvinyl chloride （PVC）are studied by differential scanning calorimetry, wide angle X-ray diffraction, scanning electron microscope and electron versatile tester. The analysis results indicate that compared with pure PVC, the crystallinity and crystallite size are increased when the content of potassium hydrogen phthalate is 3w. t. %, and a three dimension network is formed when PVC mechanical properties is increased. But with the further increasement of potassium hydrogen phthalate loading, the crystallinity and crystallite size are decreased and a hole like micromorphology is formed, and the hole diameter and its density on a plane are increased, so the thickness of PVC matrix among the holes is decreased and the transfer of stress is hampered, leading to the decline of PVC mechanical properties.