Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact...Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni（Ⅱ） DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co（CN）5X]2 （X = Br^- and N3^-） exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.展开更多
Highly active calcium chloride（CaCl2） doped Zn-Co^Ⅲdouble metal-cyanide（Ca-DMC） catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield（54 kg polymer/g catalyst） at relative low temperatur...Highly active calcium chloride（CaCl2） doped Zn-Co^Ⅲdouble metal-cyanide（Ca-DMC） catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield（54 kg polymer/g catalyst） at relative low temperature（80-115℃） toward ringopening polymerization（ROP） of propylene oxide（PO） than did DMC catalysts without modification.展开更多
Synthesis of poly(thiocarbonate)s from the copolymerization of epoxides and carbon disulfide(CS2)remains a tough challenge,due to inevitable oxygen-sulfur atom scrambling process.In this work,we utilied the oxygen-sul...Synthesis of poly(thiocarbonate)s from the copolymerization of epoxides and carbon disulfide(CS2)remains a tough challenge,due to inevitable oxygen-sulfur atom scrambling process.In this work,we utilied the oxygen-sulfur exchange reaction(0-S ER)to synthesize a random copolymer with monothiocarbonate and trithiocarbonate units from CS2 and phenyI glycidyI ether(PGE)via metal-free Lewis pairs.The copolymers contained monothiocarbonate and trithiocarbonate units of which the molar fraction could be tuned by va rying either the types of Lewis pairs or the reaction temperature.Keeping track on the intermediate provided an insight in the process of O-S ER and thus gave a hint to control the product structure.Production and consumption of phenyl thioglycidyl ether was the key process to regulate the chain structure.Remarkably,the oxygen atoms of PGE could be excluded out of the chain,resulting in the nearly complete production of poly(trithiocarbonate)s.Correspondingly,the refractive index of this kind of copolymer could be regulated in a wide range of 1.73-1.79(at 590 nm).展开更多
基金the National Natural Science Foundation of China(No.50273031)China Postdoctoral Science Foundation(No.20060400339).
文摘Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni（Ⅱ） DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co（CN）5X]2 （X = Br^- and N3^-） exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.
基金the financial supports of the National Science Foundation of the People's Republic of China(No.20704034)Provincial Natural Science Foundation of Zhejiang(No.Y4090047)
文摘Highly active calcium chloride（CaCl2） doped Zn-Co^Ⅲdouble metal-cyanide（Ca-DMC） catalysts were firstly reported.Ca-DMCs presented a very higher polymer yield（54 kg polymer/g catalyst） at relative low temperature（80-115℃） toward ringopening polymerization（ROP） of propylene oxide（PO） than did DMC catalysts without modification.
基金the Distinguished Young Investigator Fund of Zhejiang Province(LR16B040001)the National Natural Science Foundation of China(No.21774108).
文摘Synthesis of poly(thiocarbonate)s from the copolymerization of epoxides and carbon disulfide(CS2)remains a tough challenge,due to inevitable oxygen-sulfur atom scrambling process.In this work,we utilied the oxygen-sulfur exchange reaction(0-S ER)to synthesize a random copolymer with monothiocarbonate and trithiocarbonate units from CS2 and phenyI glycidyI ether(PGE)via metal-free Lewis pairs.The copolymers contained monothiocarbonate and trithiocarbonate units of which the molar fraction could be tuned by va rying either the types of Lewis pairs or the reaction temperature.Keeping track on the intermediate provided an insight in the process of O-S ER and thus gave a hint to control the product structure.Production and consumption of phenyl thioglycidyl ether was the key process to regulate the chain structure.Remarkably,the oxygen atoms of PGE could be excluded out of the chain,resulting in the nearly complete production of poly(trithiocarbonate)s.Correspondingly,the refractive index of this kind of copolymer could be regulated in a wide range of 1.73-1.79(at 590 nm).
