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
In order to obtain the optimized structure rubber, a novel miktoarm star styrene-butadiene rubber （MS- SBR） was initiated by a multifunctional macromolecular initiator with polydiene arm and Sn-C bond. The propertie...In order to obtain the optimized structure rubber, a novel miktoarm star styrene-butadiene rubber （MS- SBR） was initiated by a multifunctional macromolecular initiator with polydiene arm and Sn-C bond. The properties of MS-SBR were investigated with respect to the morphology, mechanical properties, and dynamic viscoelasticity in comparison with those of the blends, natural rubber （NR）/star styrene-butadiene random rubber （S-SBR） blend rubber and cis-l,4-polybutadiene rubber （cis-BR）/S-SBR blend rubber. The samples were analyzed using transmission elec- tron microscopy （TEM）, dynamic mechanical thermal analyzer （DMTA）, and mechanical properties test. The analy- sis results show that MS-SBR possesses the desired combination of low rolling resistance and high antiskid resistance, and is promising for application in high performance tire tread.展开更多
The effect of magnetic field and ionizing radiation on the mechanical properties of polymer blends consisting of high density polyethylene （HDPE） and acrylonitrile-butadiene rubber （NBR） has been investigated. The...The effect of magnetic field and ionizing radiation on the mechanical properties of polymer blends consisting of high density polyethylene （HDPE） and acrylonitrile-butadiene rubber （NBR） has been investigated. The purpose of the work was to create HDPE/NBR blend composites of significantly different compositions （with an excess of HDPE, intermediate ones, and with an excess of NBR） and to investigate the role of composition on mechanical deformation properties under the influence of magnetic field. The investigation has importance from the engineering viewpoint, since thermoplastic composite materials have been used as structural elements in thermonuclear and engineering fields, like wires, insulation materials and others, which are frequently subjected to mechanical loadings under the effect of magnetic field greater than 1 T. One part of the blends has been irradiated with 5 MeV accelerated electrons up to absorbed dose D equal to 150 kGy. Unirradiated and the radiation modified blends have been exposed to a constant magnetic field with induction B equal to 1.0 T, 1.5 T and 1.7 T. It is found that the action of magnetic field decreases the elastic modulus of unirradiated materials. Decrement of elastic modulus is reduced with increase of the content of NBR in composites. It is also found that preliminary irradiation noticeably decreases the effect of magnetic field. Data of the influence of the magnetic field, radiation cross-linking, and the ratio of the components on the creep are also obtained.展开更多
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 National Natural Science Foundation of China (No.50573005)
文摘In order to obtain the optimized structure rubber, a novel miktoarm star styrene-butadiene rubber （MS- SBR） was initiated by a multifunctional macromolecular initiator with polydiene arm and Sn-C bond. The properties of MS-SBR were investigated with respect to the morphology, mechanical properties, and dynamic viscoelasticity in comparison with those of the blends, natural rubber （NR）/star styrene-butadiene random rubber （S-SBR） blend rubber and cis-l,4-polybutadiene rubber （cis-BR）/S-SBR blend rubber. The samples were analyzed using transmission elec- tron microscopy （TEM）, dynamic mechanical thermal analyzer （DMTA）, and mechanical properties test. The analy- sis results show that MS-SBR possesses the desired combination of low rolling resistance and high antiskid resistance, and is promising for application in high performance tire tread.
文摘The effect of magnetic field and ionizing radiation on the mechanical properties of polymer blends consisting of high density polyethylene （HDPE） and acrylonitrile-butadiene rubber （NBR） has been investigated. The purpose of the work was to create HDPE/NBR blend composites of significantly different compositions （with an excess of HDPE, intermediate ones, and with an excess of NBR） and to investigate the role of composition on mechanical deformation properties under the influence of magnetic field. The investigation has importance from the engineering viewpoint, since thermoplastic composite materials have been used as structural elements in thermonuclear and engineering fields, like wires, insulation materials and others, which are frequently subjected to mechanical loadings under the effect of magnetic field greater than 1 T. One part of the blends has been irradiated with 5 MeV accelerated electrons up to absorbed dose D equal to 150 kGy. Unirradiated and the radiation modified blends have been exposed to a constant magnetic field with induction B equal to 1.0 T, 1.5 T and 1.7 T. It is found that the action of magnetic field decreases the elastic modulus of unirradiated materials. Decrement of elastic modulus is reduced with increase of the content of NBR in composites. It is also found that preliminary irradiation noticeably decreases the effect of magnetic field. Data of the influence of the magnetic field, radiation cross-linking, and the ratio of the components on the creep are also obtained.
