异硬脂酸铋制备及作为PVC热稳定剂的应用研究

摘要

Biostearic acid and bismuth oxide were used as the main raw materials to synthesize bismuth isostearate(BI) by two-step method and was characterized by Fourier transform infrared (FTTR)spectroscopy.Then BI applied to PVC product as a thermal stabilizer and the thermal stability of PVC stabilized with BI was studied by thermal aging oven test,Congo red test,conductivity test and thermogravimetric analysis (TGA).The results showed that when adding 4 phr BI,the initial whiteness of PVC could be maintained for 60 min and the static thermal stability time of Congo red test was 37.5 min,so BI could be used as a liquid heat stabilizer and obviously improved the initial thermal stability and long-term heat stability of PVC.Moreover,the result of quantum chemical calculation showed that BI could improve the thermal stability of PVC products by substituting unstable chlorine.%以异硬脂酸和氧化铋为主要原料,通过两步法合成异硬脂酸铋,并通过傅立叶变换红外(FT-IR)光谱表征其结构.然后将其作为热稳定剂添加到聚氯乙烯(PVC)制品中,通过热老化烘箱法、刚果红测试、电导率测试以及热重分析(TGA)研究了其对PVC的热稳定性的影响.结果表明:当PVC制品中添加4份异硬脂酸铋时,其初期白度可维持60 min,刚果红测试的静态热稳定时间达37.5 min,明显提高了PVC的初期热稳定性和长期热稳定性,所以异硬脂酸铋可以作为一种液体热稳定剂使用.还通过量子化学计算得出异硬脂酸铋改善PVC制品的热稳定性主要是通过取代不稳定氯原子来实现的.