油酸铋的合成、表征及其对PVC热稳定性的研究

The Synthesis, Characterization of Bismuth Oleate and Its Research on PVC

摘要:

以以乙酸酐、氧化铋和油酸为原料，通过两步反应合成油酸铋(BO)，并将其作为热稳定剂添加到聚氯乙烯（PVC）试片中，以提高其热稳定性。油酸铋的组成与结构通过傅里叶红外光谱（FITR）、质谱（MS）、元素分析（EA）及EDTA络合滴定法表征；通过热老化烘箱法、刚果红测试、电导率测试、热重分析（TGA）以及流变曲线法研究了油酸铋提高PVC热稳定性的作用机理。结果表明：当油酸铋的添加量为w(油酸铋)=2.60%， PVC试片的初期白度可维持60 min，刚果红测试的静态热稳定时间达39.5 min，明显提高了PVC的热稳定性，油酸铋可以作为一种液体热稳定剂使用。应用制酸力测试与络合机理的分析，认为油酸铋改善PVC的热稳定性，主要是通过油酸根取代不稳定氯原子来实现的。

Abstract:

Bismuth oleate(BO) was synthesized from acetic anhydride, bismuth oxide and oleic acid by two - step reaction, and it was added to polyvinyl chloride (PVC) as thermal stabilizer in order to improve its thermal stability. The structure of bismuth oleate was characterized by Fourier transform infrared spectroscopy (FITR), mass spectrum(MS) and the composition of bismuth oleate was determinated by elemental analysis(EA) and EDTA complexometric titrati. At the same time, the interaction mechanism of bismuth oleate improving the thermal stability of PVC was investigated by thermal aging oven test, Congo red test, conductivity test, thermogravimetric analysis (TGA) and rheological curve. The results showed that the time of the initial whiteness of PVC sheet with 2.6% bismuth oleate was 60 min, and the static stability time of Congo red was 39.5 min, so the thermal stability of PVC was improved obviously. The bismuth oleate could be used as a liquid thermal stabilizer. Moreover, from the analysis of the test of the bismuth oleate for HCl and complexing mechanism, we considered that the bismuth oleate could improve the thermal stability of PVC products mainly by the means of oleate ions substituting unstable chlorine atoms.