Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outst...Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outstanding high cis-1,4-unit selecti-vity is hypothetically originated from the presence of 4 f orbitals,that can participate in monomer coordination and thereby govern subsequent enchainment manners.This unique characteristic also renders the active species highly susceptible to Lewis bases,and may impact the overall selectivity as well as polyme-rization behavior after coordination.Nevertheless,it is still a virgin area in such a field,and the influence of Lewis bases on Nd-based diene polymerizations is still a black box.Based on this consideration,how nitrogen-containing donors(D)impacts the overall behaviors of Nd-mediated Bd polymerizations is disclosed.展开更多
End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerizatio...End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.展开更多
基金Supported by PetroChina Company Limited Project (2020 B-2711)。
文摘Neodymium(Nd)-based catalyst in butadiene(Bd)polymerization has drawn interests due to its availability in affording higher cis-1,4-unit selectivity than transition metal(Ti,Co,Ni,etc.)-based catalysts[1-2].Such outstanding high cis-1,4-unit selecti-vity is hypothetically originated from the presence of 4 f orbitals,that can participate in monomer coordination and thereby govern subsequent enchainment manners.This unique characteristic also renders the active species highly susceptible to Lewis bases,and may impact the overall selectivity as well as polyme-rization behavior after coordination.Nevertheless,it is still a virgin area in such a field,and the influence of Lewis bases on Nd-based diene polymerizations is still a black box.Based on this consideration,how nitrogen-containing donors(D)impacts the overall behaviors of Nd-mediated Bd polymerizations is disclosed.
基金Supported by PetroChina Company Limited(2020 B-2711)。
文摘End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.
基金supported by the National High Technology Research and Development Program of China(863)(2009AA064201)National Sci-Tech Support Plan,China(2012BAE05B00)~~
