邻羟基肉桂酸镧的合成及其作为PVC热稳定剂的研究

Study on the Synthesis of 2-hydroxycinnamic Acid-lanthanum and The Thermal Stabilizing Effect of PVC

以香豆素为原料,通过开环反应得到的酚酸盐与硝酸镧反应,制备了邻羟基肉桂酸镧,并通过红外光谱分析对合成产物进行了表征。通过刚果红法、变色性能测试测定了其作为PVC热稳定剂的热稳定性能。结果表明,邻羟基肉桂酸镧拥有较好的长期热稳定性能,其稳定时间为38 min,优于硬脂酸稀土、硬脂酸钙/锌、硬脂酸铅。引入硬脂酸锌和季戊四醇,与邻羟基肉桂酸镧复合作为PVC热稳定剂,在PVC的降解过程中可改善PVC的初期着色,得到明显的协同作用效果。通过转矩流变仪测试,发现加入邻羟基肉桂酸镧后PVC的塑化时间缩短为36 s,有助于PVC的塑化。

2 - hydroxycinnamic acid-lanthanum was prepared by coumarin and lanthanum nitrate, and it was analyzed by FFIR. The thermal stability of poly （vinyl chloride ） with 2 - hydroxycinnamic acid- lanthanum as a thermal stabilizer was investigated by a Congo Red test and oven aging test. The tests showed that the 2 - hydroxycinnamic acid-lanthanum had longer induction period values （t,s） compared with some of the common stabilizers used industrially, such as lead stearate, Ca-Zn stearate and cerium stearate. Blending 2 -hydroxycinnamic acid-lanthanum with ZnSt2 and pentaerythritol had synergistic effect on both the induction period and the discoloration. Torque remoter test showed plasticization of PVC could be promoted by 2 -hydroxycinnamic acid-lanthanum which was decreased to 36 s.