Anionic copolymerization of cyclic ethers with cyclic anhydrides

Polyester polyol synthesis by alternating copolymerization of propylene oxide with cyclic acid anhydrides by using double metal cyanide catalyst

“…Epoxides readily undergo anionic copolymerization with lactones and cyclic anhydrides because the propagation centers are similar-alkoxide and carboxylate [20][21][22][23][24]. Most of the polymerizations show alternating behavior with the formation of polyester, but the mechanism for alternation is unclear.…”

“…As an example, the characteristic peaks for poly(PO-co-MA) appear at 6. 23 3 (ether)]. Considering these spectroscopic assignments and the fact that no homopolymerizations are possible with cyclic anhydrides, the polyester backbones are composed of cyclic AA-PO alternating segments and partial PO self-propagation segments generating polyether backbone segments.…”

Terpolymerization of Sulfur Dioxide with Oxiranes and Cyclic Anhydrides

“…As can be seen from Table 2, at 50 8C in the copolymerization initiated by tripropylamine or pyridine the conversion of EO and SO 2 is high after several hours whereas at similar conditions the copolymerization of EO and SAn does not proceed (the anionic copolymerization of oxiranes with cyclic anhydrides is usually carried out at above 70 8C [10,11] ). Therefore, it is very probable that in the ternary systems studied the cyclic anhydrides are incorporated to the growing chain mainly as a result of the transesterification of the sulfite ion (Equation (2)), which as shown earlier [6] proceeds in high yield at 50 8C.…”

Catalytic reactions of oxetanes with protonic reagents and aprotic reagents leading to novel polymers

“…Addition reactions of epoxides with certain protonic reagents such as amines, alcohols, phenols, thiols, and carboxylic acids proceeded using appropriate catalysts to give the adducts containing hydroxy groups. [7][8][9] More than 20 years ago, Nishikubo and his coworkers developed new addition reactions of epoxides with certain aprotic reagents. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] On the other hand, oxetane has almost the same strain energy (107 kJ/mol) as epoxide 1 and its basisity of oxygen atom was higher than any other cyclic ethers.…”