Ring-opening polymerization of glycidylic compounds: influence of the glycidylic oxygen in the coordinative mechanism

A series of oxiranic monomers was synthesized and polymerized by four of th e most common aluminium-based coordinative initiators: (C2H5)(3)Al/H2O (mol e ratio 1:0.6) named Vandenberg catalyst, (C2H5)(3)Al/CH3COCH2COCH3/H2O (mo le ratio 1:1:0.5) named Vandenberg chelate catalyst, (i-PrO)(2) Al-O-Zn-O-A l(i-PrO)(2) named Teyssie catalyst and (i-PrO)(3)Al/ZnCl2 (mole ratio 1:0.5 ) named Price catalyst. They all have a different Lewis acid character. The influence of a second oxygen (glycidylic or not) on the characteristics of the polymers and conversions was studied and rationalized on the basis of a coordinative mechanism. The differences in the polymerization rate and re gioregularity of the polymers obtained are related to the electronic and co ordination effects of the neighbouring oxirane substituents. The new polyme rs were also thermally characterized.