Synthesis Of Amine Bisphenol Cobalt Metal Complexs And Its Application In The Polymerization Of Lactide And Tert-Butyl Acrylate

The problem of non-renewable energy consumption and environmental pollution is getting more and more serious.It is necessary to develop newly renewable and degradable materials.The green and versatile materials such as Polylactide(PLA)and poly(t-butyl acrylate)(PtBA)have attracted attention,which are mainly prepared by the catalytic polymerization of metal complexes.In this paper,four amine bisphenol ligands and their cobalt metal complexes were synthesized.The structures were determined using ~1H NMR and elemental analysis.Moreover,the complexes 1 and 4 were characterized by X-ray single crystal diffraction.The results show that the four cobalt metal complexes synthesized in this paper have high catalytic activity and can efficiently catalyze the ring-opening polymerization of lactides.The molecular weight of the polylactide obtained by the reaction linearly increases with the conversion rate,which is close to the theoretical molecular weight with a narrow molecular weight distribution.In addition,these catalysts can also catalyze the lactide polymerization reaction in air,which also shows a high catalytic activity.Cobalt complexes 1 and 4 can catalyze the free radical dispersion polymerization of tert-butyl acrylate.We discussed the effect of the resulting dispersion polymerization system and the polymer microsphere size by the ratio of reactants,the ratio of water to alcohol,and the amount of polyvinylpyrrolidone(PVP).Furthermore,the monomer conversion was reached 90%in the process of the polymerization.In addition,the semi-logarithmic of monomer conversion rate was increased linearly with time,which indicated that cobalt complexes 1 and 4 could mediate the free radical polymerization of tert-butyl acrylate.Moreover,a stable emulsion and uniformly dispersed polymer microspheres with uniform particle sizes were obtained through the optimization of the reaction conditions.