Synthesis of the complex of lanthanum (III) with N-(2-amino ethyl) maleamic acid radical and its application to PVC as thermal stabilizer

The complex (LaL 3 ) of lanthanum (III) with N-(2-amino ethyl) maleamic acid radical (L − ) was synthesized and characterized by Fourier infrared spectrum (FT-IR), elemental analysis and melting point measurements. The complex LaL 3 was a chelate, in which lanthanum (III) ion was coordinated with the carboxylate oxygen and amide nitrogen atoms of N-(2-amino ethyl) maleamic acid radical (L − ). The stabilization effect of LaL 3 as a thermal stabilizer on polyvinyl chloride (PVC) was evaluated by static thermal stability test, ultraviolet–visible spectrum (UV–vis), FT-IR and thermogravimetric analysis (TGA). The results showed that the addition of LaL 3 as thermal stabilizer could significantly enhance static stability time of PVC. Compared with the TG of pure PVC and LaL 3 /PVC, within the range of 200–300 °C, the degradation rate of pure PVC was significantly accelerated, whereas the degradation rate of the PVC added LaL 3 stabilizer decreased obviously. The stabilizing efficiency of PVC improved by the addition of LaL 3 is partially attributed by the formation of coordinate bonds between lanthanum (III) and chloride atoms in PVC main chain.