硬脂酸镧作为防老剂的ENR硫化胶的热稳定性

Thermal Stability of Epoxidized Natural Rubber Vulcanizates with Lanthanum Stearate as Antioxidant

采用皂化方法制备硬脂酸镧(La St),用傅立叶红外光谱法FTIR对La St进行结构表征,以La St作为环氧化天然橡胶(ENR)的防老剂,通过热重分析方法研究了防老剂RD,4010NA,4020,MB及La St对ENR硫化胶的热稳定性影响。研究结果表明:添加La St的ENR硫化胶的初始分解温度T0与T5%(重量降解5%时的温度)均高于添加防老剂RD,4010NA,4020,MB的胶料,而且添加La St的胶料的热降解活化能E也高于实验所用传统防老剂的E值,表明添加La St有助于提高ENR的热稳定性,同时添加La St的ENR的结构稳定性均显著优于传统防老剂(RD,4010NA,4020,MB)。

The structure of lanthanum stearate（ La St） synthesized by saponification was characterized by Fourier transform infrared spectroscopy（ FTIR）. La St was used as an antioxidant in ENR. The effect of La St,antioxidant RD,4010 NA,4020 and MB on thermal stability of ENR was studied by thermogravimetric analysis（ TGA）. The results showed that the initial temperature of mass loss（ T0） and the temperature at which 5% decomposition occurs（ T5） of ENR vulcanizates with La St were higher than other antioxidant. And the activation energy（ E） of thermal degradation was the highest among the used antioxidants. It is shown that the incorporation of La St could improve the thermal stability of ENR,and it is more efficient than antioxidant RD,4010 NA,4020 and MB.