氰尿酸镧的合成及其对PVC热稳定作用的研究

以氰尿酸、硝酸镧、氢氧化钠为原料合成了氰尿酸镧,利用红外光谱分析、元素分析等方法对合成产物进行了表征,通过刚果红试纸法研究了氰尿酸镧对聚氯乙烯(PVC)的热稳定作用及变色情况的影响,并与硬脂酸镧、硬脂酸钙、硬脂酸锌等热稳定剂进行了比较。结果表明:氰尿酸根和镧离子发生了配位作用,使得氰尿酸镧具有良好的热稳定作用,当氰尿酸镧用量为PVC的2.5%时,PVC的热稳定时间可达到80 min;氰尿酸镧与硬脂酸锌之间有明显的协同作用,二者复配可以有效改善氰尿酸镧的初期着色性,当氰尿酸镧/硬脂酸锌=1/3、总用量为PVC的2.5%时,PVC的热稳定时间可达到26 min。

Study on Synthesis of Lanthanum Cyanuric and Its Thermal Stabilizing Effect on PVC

Lanthanum cyanuric was synthesized from cyanuric acid,lanthanum nitrate and sodium hydroxide.The synthesized product was characterized by FTIR and element analysis.The effect of lanthanum cyanuric on thermal stabilization and discoloration of PVC was studied by Congo red test,and also compared with lanthanum stearate,calcium stearate,zinc stearate.The results show that there is coordination effect between cyanuric acidic group and lanthanum ion,which imparts excellent thermal stability for lanthanum cyanuric;when lanthanum cyanuric content is 2.5% of PVC,the thermal stabilization time of PVC is 80 min;there is obvious synergistic effect between lanthanum cyanuric and zinc stearate,their composite can improve the initial discoloration of pure lanthanum cyanuric,when lanthanum cyanuric/zinc stearate=1/3,total content is 2.5% of PVC,the thermal stabilization time of PVC is up to 26 min.