The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Christina Escobedo - One of the best experts on this subject based on the ideXlab platform.
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kinetic studies of the alternating copolymerization of Cyclic Acid Anhydrides and epoxides and the terpolymerization of Cyclic Acid Anhydrides epoxides and co2 catalyzed by salen criiicl
Macromolecules, 2012Co-Authors: Donald J Darensbourg, Ross R Poland, Christina EscobedoAbstract:Copolymerization of a series of Cyclic Acid Anhydrides with several epoxides using (salen)CrCl/onium salt catalysts has afforded polyesters with high molecular weights and narrow molecular weight distributions. The (salen)CrCl catalyst in the presence of the onium salts with formula PPNX (X = Cl–, N3–) for the copolymerization of the Anhydrides, maleic (MA), succinic (SA), phthalic (PA), cyclohexene (CHE), and cyclohexane (CHA) with the epoxides, cyclohexene oxide (CHO), propylene oxide (PO), and styrene oxide (SO) resulted in completely alternating enchainment of monomers to provide pure polyesters. Temperature dependent studies of the ring-opening copolymerization of phthalic Anhydride and cyclohexene oxide monomers in toluene solution have yielded activation parameters of ΔH‡ = 67.5 kJ mol–1 and ΔS‡ = −95.3 J mol–1, where the rate limiting step was ring-opening of the epoxide by the enchained Anhydride. For the Cyclic Acid Anhydride (CHA), the relative order of reactivity with epoxides decreased PO > C...
Donald J Darensbourg - One of the best experts on this subject based on the ideXlab platform.
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kinetic studies of the alternating copolymerization of Cyclic Acid Anhydrides and epoxides and the terpolymerization of Cyclic Acid Anhydrides epoxides and co2 catalyzed by salen criiicl
Macromolecules, 2012Co-Authors: Donald J Darensbourg, Ross R Poland, Christina EscobedoAbstract:Copolymerization of a series of Cyclic Acid Anhydrides with several epoxides using (salen)CrCl/onium salt catalysts has afforded polyesters with high molecular weights and narrow molecular weight distributions. The (salen)CrCl catalyst in the presence of the onium salts with formula PPNX (X = Cl–, N3–) for the copolymerization of the Anhydrides, maleic (MA), succinic (SA), phthalic (PA), cyclohexene (CHE), and cyclohexane (CHA) with the epoxides, cyclohexene oxide (CHO), propylene oxide (PO), and styrene oxide (SO) resulted in completely alternating enchainment of monomers to provide pure polyesters. Temperature dependent studies of the ring-opening copolymerization of phthalic Anhydride and cyclohexene oxide monomers in toluene solution have yielded activation parameters of ΔH‡ = 67.5 kJ mol–1 and ΔS‡ = −95.3 J mol–1, where the rate limiting step was ring-opening of the epoxide by the enchained Anhydride. For the Cyclic Acid Anhydride (CHA), the relative order of reactivity with epoxides decreased PO > C...
Mikiharu Kamachi - One of the best experts on this subject based on the ideXlab platform.
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Polymerization of azastyrene derivatives, 4. Spontaneous copolymerization of 2,6-diisopropyl-N-methyleneaniline and Cyclic Acid Anhydride
Designed Monomers and Polymers, 2004Co-Authors: Akihito Hashidzume, Yukie Kurokawa, Akira Harada, Mikiharu KamachiAbstract:The spontaneous copolymerization of 2,6-diisopropyl-N-methyleneaniline (DiPMAn) with phthalic Anhydride (PhAnh) or with itaconic Anhydride (IAnh) was investigated. For both the pairs, copolymers of M n ≥ 7.8 × 103 were obtained under appropriate conditions. The yield and mole fraction of DiPMAn of the copolymers obtained by copolymerization at varying mole fractions of DiPMAn in the comonomer feed were indicative of alternating copolymerization. On the basis of the elemental analysis and IR and1H-NMR spectroscopic data, it was concluded that, in the case of the copolymerization of DiPMAn and PhAnh, the copolymer was formed by coupling reaction of a zwitterionic one-to-one adduct, and that, in the case of the copolymerization of DiPMAn and IAnh, the copolymer was formed not only by coupling reaction of a zwitterionic adduct but also by the addition polymerization through the C=C bond in the IAnh moiety. For both cases, the zwitterion mechanism was confirmed by isolation of low-molecular-weight products fro...
Ross R Poland - One of the best experts on this subject based on the ideXlab platform.
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kinetic studies of the alternating copolymerization of Cyclic Acid Anhydrides and epoxides and the terpolymerization of Cyclic Acid Anhydrides epoxides and co2 catalyzed by salen criiicl
Macromolecules, 2012Co-Authors: Donald J Darensbourg, Ross R Poland, Christina EscobedoAbstract:Copolymerization of a series of Cyclic Acid Anhydrides with several epoxides using (salen)CrCl/onium salt catalysts has afforded polyesters with high molecular weights and narrow molecular weight distributions. The (salen)CrCl catalyst in the presence of the onium salts with formula PPNX (X = Cl–, N3–) for the copolymerization of the Anhydrides, maleic (MA), succinic (SA), phthalic (PA), cyclohexene (CHE), and cyclohexane (CHA) with the epoxides, cyclohexene oxide (CHO), propylene oxide (PO), and styrene oxide (SO) resulted in completely alternating enchainment of monomers to provide pure polyesters. Temperature dependent studies of the ring-opening copolymerization of phthalic Anhydride and cyclohexene oxide monomers in toluene solution have yielded activation parameters of ΔH‡ = 67.5 kJ mol–1 and ΔS‡ = −95.3 J mol–1, where the rate limiting step was ring-opening of the epoxide by the enchained Anhydride. For the Cyclic Acid Anhydride (CHA), the relative order of reactivity with epoxides decreased PO > C...
Akihito Hashidzume - One of the best experts on this subject based on the ideXlab platform.
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Polymerization of azastyrene derivatives, 4. Spontaneous copolymerization of 2,6-diisopropyl-N-methyleneaniline and Cyclic Acid Anhydride
Designed Monomers and Polymers, 2004Co-Authors: Akihito Hashidzume, Yukie Kurokawa, Akira Harada, Mikiharu KamachiAbstract:The spontaneous copolymerization of 2,6-diisopropyl-N-methyleneaniline (DiPMAn) with phthalic Anhydride (PhAnh) or with itaconic Anhydride (IAnh) was investigated. For both the pairs, copolymers of M n ≥ 7.8 × 103 were obtained under appropriate conditions. The yield and mole fraction of DiPMAn of the copolymers obtained by copolymerization at varying mole fractions of DiPMAn in the comonomer feed were indicative of alternating copolymerization. On the basis of the elemental analysis and IR and1H-NMR spectroscopic data, it was concluded that, in the case of the copolymerization of DiPMAn and PhAnh, the copolymer was formed by coupling reaction of a zwitterionic one-to-one adduct, and that, in the case of the copolymerization of DiPMAn and IAnh, the copolymer was formed not only by coupling reaction of a zwitterionic adduct but also by the addition polymerization through the C=C bond in the IAnh moiety. For both cases, the zwitterion mechanism was confirmed by isolation of low-molecular-weight products fro...
