The Synthesis And Catalysis Of [ONSO]AlCl Complexes In The Polymerization Of Epoxides

Polyethers are important class of materials with great commercial value which are commonly used to manufacture products such as foams,surfactants,elastomers,and biomedical components and widely available for industrial purposes as well as in our daily life.As widely used polymer materials,polyesters and polycarbonates have been widely used in various fields,such as packaging,fiber,hard plastics and engineering materials.Aluminum with low cost and environmental protection is taken as the catalytic active centers of aluminum complexes.And they can be used as an effective catalyst for the homo-polymerization of epoxides and copolymerization of epoxides and anhydride/carbon dioxide for the synthesis of polyethers and polyesters/polycarbonates.The main contents of this paper are as follows:1?Three kinds of[ONSO]type similar Salen ligands that nitrogen,sulfur and oxygen were used as coordination atoms were synthesised.They were reacted with diethylaluminum chloride and three kinds of complexes?[ONSO]AlCl?were synthesized,including complexe 1 with electron donating group?-t-Bu?and using ethyl as the skeleton structure,complexe 2 with electron withdrawing group?-Cl?and using ethyl as the skeleton structure and complexe 3 with electron donating group?-t-Bu?and using benzene ring as the skeleton structure.2?The[ONSO]type aluminum complexes were used as catalysts in ring-opening polymerization of epoxides,the results showed that they cannot effectively catalyze the copolymerization of epoxides and carbon dioxide/anhydrides for synthesizing polycarbonates/polyesters,however,good catalytic activities were showed in the homopolymerization of epoxides for synthesizing polyethers.In the ring-opening polymerization of cyclohexene oxide,the homopolymerization of cyclohexene oxide?CHO?was catalyzed effectively by three kinds of complexes in the presence of phthalic anhydride?PA?,and the turnover frequency of cyclohexene oxide to products?TOF?value can be reached 152 h^-1.The reaction parameters,such as PA proportion,molar ratio,temperature,reaction time and different anhydrides were employed in order to study the influences on the polymeration activity using complexe 1.And the reaction mechanism was discussed.3?In the synthesis of poly?4-vinyl cyclohexene oxide??PVCHO?,the activity of complex 1 was highest at(245 h^-1)in the three kinds of complexes under the same amount of phthalic anhydride?PA?.The effects of polymeration parameters,such as PA proportion,molar ratio,reaction time and temperature were systematically studied.And the reaction mechanism was discussed.The side chain structure of PVCHO was modified,such as the epoxidation of double bond and cyclic carbonate.