不同脂肪酸钙和脂肪酸锌热稳定作用机制研究

摘要

Calcium/zinc stearate, calcium/zinc lauriate, calcium/zinc sebaciate, PDOP, PER were used as thermal stabilizers of PVC. Contrast of thermal stability among different calcium and zinc carboxylates was investigated by means of heat aging test, conductivity test, and UV spectroscopy. The thermal stable mechanism of calcium stearate and zinc stearate was investigated. The results showed that: calcium stearate exhibited best heat stability; Ca/Zn stearate had better synergy effect; Ca/Zn lauric and diisooctyl phenyl phosphite (PDOP) exhibited best synergy; Ca/Zn lauric and pentaerythritol (PER) can inhibit PVC from forming conjugated long-chain olefins, meanwhile, Ca/Zn stearate and PER can inhibit PVC from forming conjugated short-chain olefins. Calcium stearate can absorb hydrogen chloride which came from PVC's degradation; zinc stearate can take place of unstable chlorine atom in PVC.%将硬脂酸钙/硬脂酸锌、月桂酸钙/月桂酸锌、癸二酸钙/癸二酸锌、亚磷酸-苯二异辛酯(PDOP)、季戊四醇(PER)作为稳定剂应用于聚氯乙烯(PVC)中,通过热老化法、电导法和紫外光谱分析法对比了上述不同脂肪酸钙和脂肪酸锌稳定剂的热稳定特性,并进一步研究了单独脂肪酸钙和脂肪酸锌的热稳定机理.结果表明:单独硬脂酸钙的热稳定性相对较好;硬脂酸钙/脂肪酸锌的协同效应相对较好;月桂酸钙/月桂酸锌/PDOP的协同效应最为明显;月桂酸钙/月桂酸锌/PER能有效抑制PVC降解形成共轭长链烯烃,硬脂酸钙/硬脂酸锌/PER能有效抑制PVC降解形成共轭短链烯烃;硬脂酸钙能吸收PVC降解所产生氯化氢,硬脂酸锌能置换PVC中的不稳定氯原子.