Well-controlled polymerization by metalloporphyrin. Synthesis of copolymer with alternating sequence and regulated molecular weight from cyclic acid anhydride and epoxide catalyzed by the system of aluminum porphyrin coupled with quaternary organic salt

Abstract

The system of (5,10,15,20-tetraphenylporphinato)aluminum chloride coupled with ethyltriphenylphosphonium bromide is a novel and efficient initiator for the living and alternating copolymerization of phthalic anhydride and epoxide. The "living" polyester thus formed initiates the copolymerization of phthalic anhydride and epoxide as well as the homopolymerization of epoxide, 0-lactone, or «-lactone to give the corresponding binary and/or ternary block copolymers of a desired block sequence with well-regulated chain length.

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.…”

Ring‐Opening Polymerization

“…For example, anionic copolymerization of a lactam with an epoxide does not occur since the anion derived from the epoxide terminates by proton abstraction from lactam monomer. Epoxides readily undergo anionic copolymerization with lactones and cyclic anhydrides because the propagating centers are similar-alkoxide and carboxylate [Aida et al, 1985;Cherdron and Ohse, 1966;Inoue and Aida, 1989;Luston and Vass, 1984]. Most of the polymerizations show alternating behavior, with the formation of polyester, but the mechanism for alternation is unclear.…”

“…The sequential addition method also allows the synthesis of many different block copolymers in which the two monomers have different functional groups, such as epoxide with lactone, lactide or cyclic anhydride, cyclic ether with 2-methyl-2-oxazoline, imine or episulfide, lactone with lactide or cyclic carbonate, cycloalkene with acetylene, and ferrocenophane with cyclosiloxane [Aida et al, 1985;Barakat et al, 2001;Farren et al, 1989;Inoue and Aida, 1989;Keul et al, 1988;Kobayashi et al, 1990a,b,c;Massey et al, 1998;Yasuda et al, 1984].…”

Anionic Ring-Opening Polymerization

“…(48) Systems of diethylzinc reacted with alcohols are also effective initiators for the alternating copolymerization of epoxides and cyclic anhydrides at a relatively high temperature, such as 80°C. Use of the system of dialkylzinc coupled with an optically active alcohol such as d-( + )-borneol as initiator for the copolymerization of racemic 1,2-epoxypropane and 3-phenyl-a 4 -tetrahydrophthalic anhydride (8) affords a polyester with optical activity, which results from the asymmetric selection of the optical antipodes of the anhydride by the chiral initiator.…”