The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49....The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49.5 kg/mol)were enabled through zwitterionic ring-opening polymerization(ZROP)of macrocyclic carbonates(MCs)mediated by N-heterocyclic carbene(NHC).The thermodynamic behavior of polymerization depends on the ring size of monomers.During this process,the ZROP of 11-membered MC was driven by the change of enthalpy(ΔH_(p))which differed from the ZROP of 14-membered MC driven by the entropic change(ΔS_(p)).Cyclic polycarbonates depicted improved thermostability(T_(d5%)≥204℃)and higher glass transition temperatures(T_(g)>–40℃)in comparison to their linear analogues(T_(d5%)≤185℃,T_(g)~–50℃).In addition,the mechanism of ZROP of MC was addressed through computational study.A distinct mechanism of polymerization distinguishable from the well-known NHC-mediated ZROP of cyclic esters was revealed,where the zwitterion from nucleophilic addition to MC,i.e.tetrahedral intermediate,cannot be ring-opened probably due to the delocalization of negative charge on the carbonate group,but serves as an active center for the polymerization.In comparison to PEG,the attained polymer demonstrated comparable hydrophilic and biocompatible properties,as revealed by the results of contact angle and in vitro cytotoxicity studies,suggesting that cyclic polycarbonate hold the promise as the alternative of PEG.展开更多
As a powerful synthetic tool,ruthenium-catalyzed ring-opening metathesis polymerization(ROMP)has been widely utilized to prepare diverse heteroatom-containing polymers.In this contribution,we report the synthesis of t...As a powerful synthetic tool,ruthenium-catalyzed ring-opening metathesis polymerization(ROMP)has been widely utilized to prepare diverse heteroatom-containing polymers.In this contribution,we report the synthesis of the novel imine-based polymer through the copolymerization of cyclooctene with cyclic imine comonomer via ROMP.Because of the efficient hydrolysis reactions of the imine group,the generated copolymer can be easily degraded under mild condition.Moreover,the generated degradable product was the telechelic polymer bearing amine group,which was highly challenged for its direct synthesis.And this telechelic polymer could also be used for the further synthesis of new polymer through post-transformation.The introduction of imine unit in this work provides a new example of the degradable polymer synthesis.展开更多
Although solid-state polymer electrolytes(SPEs)are expected to solve the safety hazards and limited energy density in the energy storage systems,they still encounter an inferior electrode/electrolyte interface when pr...Although solid-state polymer electrolytes(SPEs)are expected to solve the safety hazards and limited energy density in the energy storage systems,they still encounter an inferior electrode/electrolyte interface when prepared in an ex situ manner.Recently,in situ polymerization of SPEs favor high interfacial infiltrability,improved interface contact,and reduced interface resistance,owing to the formation of a"superconformal"interface between electrode and electrolyte.Especially,in situ strategies employing ring-opening polymerization(ROP)are emerging as dazzling stars,further enabling moderate polymerization conditions,controllable molecular structure,and reduced interfacial side reaction.As the main monomers that can be in situ polymerized via the ROP strategy,cyclic ethers have been used to construct the CE-SPEs with many merits,including good battery electrochemical performances and a simple assembly process.Here,as a systematic summarization of the existing reports,this review focuses on the polymerization mechanism of ROP,the design principles of CE-SPEs electrolytes,and the recent application of in situ CE-SPEs.In particular,this review thoroughly discusses the selection of different cyclic monomers,initiators and various modification approaches in in situ fabricating CE-SPEs.Ending with offering future challenges and perspectives,this review envisions shedding light on the profound understanding and scientific guidance for further development of high-performance in situ CE-SPEs.展开更多
Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the ...Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.展开更多
Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving t...Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.展开更多
Practical Zn metal batteries have been hindered by several challenges,including Zn dendrite growth,undesirable side reactions,and unstable electrode/electrolyte interface.These issues are particularly more serious in ...Practical Zn metal batteries have been hindered by several challenges,including Zn dendrite growth,undesirable side reactions,and unstable electrode/electrolyte interface.These issues are particularly more serious in low-concentration electrolytes.Herein,we design a Zn salt-mediated electrolyte with in situ ring-opening polymerization of the small molecule organic solvent.The Zn(TFSI)_(2)salt catalyzes the ring-opening polymerization of(1,3-dioxolane(DOL)),generating oxidation-resistant and non-combustible long-chain polymer(poly(1,3-dioxolane)(pDOL)).The pDOL reduces the active H_(2)O molecules in electrolyte and assists in forming stable organic–inorganic gradient solid electrolyte interphase with rich organic constituents,ZnO and ZnF_(2).The introduction of pDOL endows the electrolyte with several advantages:excellent Zn dendrite inhibition,improved corrosion resistance,widened electrochemical window(2.6 V),and enhanced low-temperature performance(freezing point=-34.9°C).Zn plating/stripping in pDOL-enhanced electrolyte lasts for 4200 cycles at 99.02%Coulomb efficiency and maintains a lifetime of 8200 h.Moreover,Zn metal anodes deliver stable cycling for 2500 h with a high Zn utilization of 60%.A Zn//VO_(2)pouch cell assembled with lean electrolyte(electrolyte/capacity(E/C=41 mL(Ah)^(-1))also demonstrates a capacity retention ratio of 92%after 600 cycles.These results highlight the promising application prospects of practical Zn metal batteries enabled by the Zn(TFSI)2-mediated electrolyte engineering.展开更多
Zwitterionic polymers are polymers containing a pair of oppositely charged groups in their repeating units,which facilitate the formation of a hydration layer on the surface through ionic solvation.This strong hydrati...Zwitterionic polymers are polymers containing a pair of oppositely charged groups in their repeating units,which facilitate the formation of a hydration layer on the surface through ionic solvation.This strong hydration results in the remarkable properties of zwitterionic polymer hydrogels,including antifouling,lubricating,and anti-freezing capabilities.Owing to these properties,zwitterionic polymer hydrogels have attracted notable attention in biomedical and engineering fields.However,the superhydrophilicity of zwitterionic polymer hydrogels renders them brittle and weak,considerably limiting their use in load-bearing applications.Thus,there is an urgent need to improve the mechanical properties of zwitterionic hydrogels.In this work,we systematically review mechanical enhancement strategies for zwitterionic polymer hydrogels.We cover strate-gies applicable to hybrid and pure high-strength zwitterionic polymer hydrogels.Additionally,we discuss the advantages and limitations of various strength enhancement strategies.展开更多
Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)o...Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important role.Herein a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and characterized.In combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction temperature.By changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were prepared.The kinetic and chain extension experiments were carried out to prove the"living"/controllable feature.And the NMR experiments were used to support the proposal of possible mechanism.展开更多
A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a cat...A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a catalyst for the polymerization reaction system.And polytetrahydrofuran with high molecular weight and narrow molecular weight distribution could be obtained.The proposed mechanism was studied by MALDI-TOF,ESI-MS and O-18 isotope labeling analyses as a metal-free coordination insertion mechanism.展开更多
Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to p...Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to prevent degradation and side reactions.In the contribution,histidine N-thiocarboxyanhydride(His-NTA)is directly synthesized in aqueous solution without protection.With the self-catalysis of the imidazole side group,the ring-closing reaction to form His-NTA does not require any activating reagent(e.g.,phosphorus tribromide),which is elucidated by density functional theory(DFT)calculations.His-NTA directly polymerizes into PHis bearing unprotected imidazole groups with designable molecular weights(4.2-7.7 kg/mol)and low dispersities(1.10-1.19).Kinetic experiments and Monte Carlo simulations reveal the elementary reactions and the relationship between the conversion of His-NTA and time during polymerization.Block copolymerization of His-NTA with sarcosine N-thiocarboxyanhydride(Sar-NTA)demonstrate versatile construction of functional polypept(o)ides.The triblock copoly(amino acid)PHis-b-PSar-b-PHis is capable to reversibly coordinate with transition metal ions(Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+)and Zn^(2+))to form pH-sensitive hydrogels.展开更多
Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymeriza...Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymerization of o-phthalaldehyde(OPA)and epoxide using Lewis pair type two-component organocatalysts for producing acetal-functionalized polyether and polyurethane.Notably,triethylborane as the Lewis acid,in comparison with tri(n-butyl)borane,more effectively enhances the polymerization activity by mitigating borane-induced reduction of the aldehyde group into extra initiating(borinic ester)species.Density functional theory(DFT)calculations present comparable energy barriers of OPA-epoxide cross-propagation and epoxide self-propagation,which is consistent with the experimental finding that an alternating-rich copolymer comprising mostly OPA-epoxide units but also epoxide-epoxide linkages is produced.In particular,when epoxide is added in a large excess,the product becomes a polyether containing acetal functionalities in the central part of the backbone and thus being convertible into polyurethane with refined acid degradability.展开更多
Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteris...Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteristics.However,their inherently low ion transport efficiency poses a major challenge for their application in LMBs.To address this issue,covalent organic framework(COF)with their ordered ion transport channels,chemical stability,large specific surface area,and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction.Here,we prepared an anionic COF,Tp Pa-COOLi,which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs.The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores,forming additional COF-polymer junctions that enhance ion transport pathways.The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix,preserving ion transport channels and facilitating ion transport across COF grain boundaries.By controlling variables to alter the crystallinity of Tp Pa-COOLi and the presence of-COOLi substituents,Tp Pa-COOLi with partial long-range order and-COOLi substituents exhibited superior electrochemical performance.This research demonstrates the potential in constructing high-performance SPEs for LMBs.展开更多
Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with...Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.展开更多
Highly potent ionic organocatalyst is developed for room-temperature controlled ring-opening polymerization(ROP)of lactones,includingδ-valerolactone,ε-caprolactone,andδ-hexalactone.The catalysts are prepared by sim...Highly potent ionic organocatalyst is developed for room-temperature controlled ring-opening polymerization(ROP)of lactones,includingδ-valerolactone,ε-caprolactone,andδ-hexalactone.The catalysts are prepared by simply mixing tetra-n-butyl ammonium hydroxide and a(thio)urea at elevated temperature under vacuum,and used in cooperation with an alcoholic initiator.The performance of the catalyst is readily adjusted and optimized through variation of the(thio)urea precursor,catalyst composition,and reaction condition.Urea-derived catalysts are generally superior to thiourea-derived ones.Provided with proper N-substituents,the catalyst affords both high polymerization efficiency and high selectivity for monomer enchainment over macromolecular transesterification,even at high monomer conversion and/or substantially extended reaction time.In addition to acidity,structural symmetry of the urea also proves decisive for the catalytic activity,which enables a catalyst-assisted proton transfer process for the ring-opening of lactone and thus provides a novel mechanistic insight for ROP catalyzed by hydrogen-bonding type bifunctional ionic organocatalysts.展开更多
In this paper,ring-opening polymerization of trimethylene carbonate(TMC)with rare earth(Nd,Y,La)ρ-tert- butylcalix[n]arene(n=4,6,and 8)complexes as catalysts has been studied.Poly(trimethylene carbonate)(PTMC)with M_...In this paper,ring-opening polymerization of trimethylene carbonate(TMC)with rare earth(Nd,Y,La)ρ-tert- butylcalix[n]arene(n=4,6,and 8)complexes as catalysts has been studied.Poly(trimethylene carbonate)(PTMC)with M_v of 21,400 was produced by bulk polymerization under the conditions as follows:[TMC]_0/[Nd](molar ratio)=1000,80℃, 8 h.Mechanism study reveals that the polymerization proceeds via a coordination mechanism.展开更多
A series of zinc silylamido complexes based upon NNO tridentate enolic Schiff base framework have been synthesized and characterized. These complexes were tested for the ring opening polymerization of lactide and e-ca...A series of zinc silylamido complexes based upon NNO tridentate enolic Schiff base framework have been synthesized and characterized. These complexes were tested for the ring opening polymerization of lactide and e-caprolactone, exhibiting notably high activity at ambient temperature, The influence of imine bridge length and substituents of diketone over the course of polymerization was investigated in details. Remarkably, 4a was confirmed to be a rare example of exceedingly active and robust zinc catalysts, achieving major transformation of lactide under extremely low loading （0.025 mol%） within 18 rain. The influence of various monomers as well as the polymerization mechanism have also been discussed.展开更多
The ring-opening polymerization of e-caprolactone (CL) initiated by novel single lanthanide tris(4-tert-butylphenolate)s [Ln(OTBP)3] is reported. Single-component La(OTBP)3 can effectively prepare polycaprolactone (PC...The ring-opening polymerization of e-caprolactone (CL) initiated by novel single lanthanide tris(4-tert-butylphenolate)s [Ln(OTBP)3] is reported. Single-component La(OTBP)3 can effectively prepare polycaprolactone (PCL) with over 90% yield and viscosity average molecular weight about 60 x 10 under quite mild conditions: molar ratio of CL to initiator is 1000, 60 C, 2 h in toluene. Mechanism study indicates that the monomer inserts into the growing chain via the break of acyl-oxygen bond of CL.展开更多
Two types of bifunctional bis（salicylaldimine） ligands（syn-L and anti-L） were designed and synthesized to support bimetallic aluminum complexes. Owing to the rigid anthracene skeleton, syn-L and anti-L successfull...Two types of bifunctional bis（salicylaldimine） ligands（syn-L and anti-L） were designed and synthesized to support bimetallic aluminum complexes. Owing to the rigid anthracene skeleton, syn-L and anti-L successfully locked two Al centers in close proximity（syn-Al2） and far apart（anti-Al2）, respectively. The distance between two Al centers in syn-Al2 was defined by X-ray diffraction as 6.665 ？, which is far shorter than that in anti-Al2. In the presence of stoichiometrical Bn OH, syn-Al2 and anti-Al2 were both efficient for ring-opening polymerization（ROP） of rac-LA with the former being more active. In the presence of excess Bn OH, syn-Al2 showed an efficient and immortal feature, consistent with high conversions, matched Mns, narrow molecular weight distributions and end group fidelity, while anti-Al2 had a much lower activity or even became entirely inactive due to rapid decomposition, indicated by in situ ～1H-NMR experiments of Al complexes with Bn OH.展开更多
(Imido)vanadium(V)-alkylidene complexes of type V(CHSiMe3)(NR)(OR?)(PMe3)2 [R = Ad, C6H5, 2,6-Me2C6H3, 2,6-Cl2C6H3;R?= 2,6-Me2C6H3, 2,6-i Pr2C6H3, 2,6-F2C6H3, C6F5, C6Cl5] exhibited from moderate to remarkable catalyt...(Imido)vanadium(V)-alkylidene complexes of type V(CHSiMe3)(NR)(OR?)(PMe3)2 [R = Ad, C6H5, 2,6-Me2C6H3, 2,6-Cl2C6H3;R?= 2,6-Me2C6H3, 2,6-i Pr2C6H3, 2,6-F2C6H3, C6F5, C6Cl5] exhibited from moderate to remarkable catalytic activities for ringopening metathesis polymerization(ROMP) of norbornene(NBE). The catalytic activities were affected by the ligand substituents, and V(CHSiMe3)(N-2,6-Cl2C6H3)(OC6X5)(PMe3)2(X = F, Cl) demonstrated the exceptionally high catalytic activities for ROMP of NBE.The complexes polymerized cycloheptene(CHPE) and cis-cyclooctene(COE), and ROMP of COE by the OC6 Cl5 analogue proceeded in a living manner even at 80℃, and the activity increased with increasing the temperature up to 120 ℃. Highly active catalysts for ROMP of cyclic olefins(NBE, cyclopentene, and CHPE) can be generated in situ by premixing isolated V(CHSiMe3)(NC6F5)(O-2,6-iPr2C6H3)(PMe3)2 with 1.0 equiv. of C6F5OH or C6Cl5OH via immediate phenoxy exchange;the activity was affected by the kind of phenol added [TOF in the ROMPs of NBE: 4.62 × 10^4 min^–1(upon addition of C6F5OH) versus 37.3 min^–1(none)].展开更多
Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalys...Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalyst still remains a scientific challenge. Here we report our investigations into organocatalytic stereoselective ROP of rac-LA by utilizing novel bulky chiral and achiral N-heterocyclic carbenes（NHC）, 1,3-bis-（1′-naphthylethyl）imidazolin-2-ylidene. The effect of polymerization conditions（e.g. solvent, temperature, alcohol initiator） on ROP behavior by these bulky NHCs has been fully studied, leading to the formation of isotactic-rich stereoblock polylactide（Pi = 0.81） under optimized conditions with high activity（Conv. = 98% in 30 min） and narrow molecular weight dispersity（D = 1.05）.展开更多
基金the China Postdoc Council(OCPC)for the financial support of Postdoctoral International Exchange Program(No.YJ20210095)the financial support from the National Natural Science Foundation of China(No.22078150)+3 种基金National Key R&D Program of China(No.2021YFC2101904)the Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the Jiangsu Synergetic Innovation Center for Advanced Bio-Manufacture(No.XTB2201)the Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)。
文摘The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49.5 kg/mol)were enabled through zwitterionic ring-opening polymerization(ZROP)of macrocyclic carbonates(MCs)mediated by N-heterocyclic carbene(NHC).The thermodynamic behavior of polymerization depends on the ring size of monomers.During this process,the ZROP of 11-membered MC was driven by the change of enthalpy(ΔH_(p))which differed from the ZROP of 14-membered MC driven by the entropic change(ΔS_(p)).Cyclic polycarbonates depicted improved thermostability(T_(d5%)≥204℃)and higher glass transition temperatures(T_(g)>–40℃)in comparison to their linear analogues(T_(d5%)≤185℃,T_(g)~–50℃).In addition,the mechanism of ZROP of MC was addressed through computational study.A distinct mechanism of polymerization distinguishable from the well-known NHC-mediated ZROP of cyclic esters was revealed,where the zwitterion from nucleophilic addition to MC,i.e.tetrahedral intermediate,cannot be ring-opened probably due to the delocalization of negative charge on the carbonate group,but serves as an active center for the polymerization.In comparison to PEG,the attained polymer demonstrated comparable hydrophilic and biocompatible properties,as revealed by the results of contact angle and in vitro cytotoxicity studies,suggesting that cyclic polycarbonate hold the promise as the alternative of PEG.
基金financially supported by National Key R&D Program of China(No.2021YFA1501700)CAS Project for Young Scientists in Basic Research(No.YSBR-094)+1 种基金Natural Science Foundation of Anhui Province(Nos.2308085Y35 and 2023AH030002)Hefei Natural Science Foundation(No.202304)。
文摘As a powerful synthetic tool,ruthenium-catalyzed ring-opening metathesis polymerization(ROMP)has been widely utilized to prepare diverse heteroatom-containing polymers.In this contribution,we report the synthesis of the novel imine-based polymer through the copolymerization of cyclooctene with cyclic imine comonomer via ROMP.Because of the efficient hydrolysis reactions of the imine group,the generated copolymer can be easily degraded under mild condition.Moreover,the generated degradable product was the telechelic polymer bearing amine group,which was highly challenged for its direct synthesis.And this telechelic polymer could also be used for the further synthesis of new polymer through post-transformation.The introduction of imine unit in this work provides a new example of the degradable polymer synthesis.
基金supported by the National Natural Science Foundation of China(22022813)the Zhejiang Provincial Natural Science Foundation of China(LQ24B030002)the China Postdoctoral Science Foundation(2022M722729,2023T160571).
文摘Although solid-state polymer electrolytes(SPEs)are expected to solve the safety hazards and limited energy density in the energy storage systems,they still encounter an inferior electrode/electrolyte interface when prepared in an ex situ manner.Recently,in situ polymerization of SPEs favor high interfacial infiltrability,improved interface contact,and reduced interface resistance,owing to the formation of a"superconformal"interface between electrode and electrolyte.Especially,in situ strategies employing ring-opening polymerization(ROP)are emerging as dazzling stars,further enabling moderate polymerization conditions,controllable molecular structure,and reduced interfacial side reaction.As the main monomers that can be in situ polymerized via the ROP strategy,cyclic ethers have been used to construct the CE-SPEs with many merits,including good battery electrochemical performances and a simple assembly process.Here,as a systematic summarization of the existing reports,this review focuses on the polymerization mechanism of ROP,the design principles of CE-SPEs electrolytes,and the recent application of in situ CE-SPEs.In particular,this review thoroughly discusses the selection of different cyclic monomers,initiators and various modification approaches in in situ fabricating CE-SPEs.Ending with offering future challenges and perspectives,this review envisions shedding light on the profound understanding and scientific guidance for further development of high-performance in situ CE-SPEs.
基金financially supported by the National Key R&D Program of China(No.2021YFA1501700)the National Natural Science Foundation of China(Nos.22371194 and 22301197)Fundamental Research Funds from Sichuan University(Nos.2023SCUNL103 and 2024SCUQJTX005)。
文摘Chemically recyclable polythioesters are of particular interest owing to their unique properties and desired sustainability.By the exploit of a benzo-fusion strategy toε-thiocaprolactone,we successfully improved the chemical recyclability and regulated the thermal and mechanical properties of the resulting polythioesters.The efficient ring-opening polymerization(ROP)of benzo-fused thiolactone monomers(M)containing different substituents gave rise to high-molecular-weight semi-aromatic polythioesters P(M)s.The resulting P(M)s showcased tunable physical and mechanical properties.The debenzylation of P(M3)was able to generate P(M3-OH)with free hydroxyl sidechains.Notably,chemical recycling of the resulting P(M)s back to their corresponding monomers via bulk thermal depolymerization achieved high efficiency(>95%yield,99%purity),establishing a closed-loop lifecycle.
基金supported by the National Natural Science Foundation of China(No.U23B6011)the Jilin Provincial Science and Technology Department Program(No.20230101347JC)。
文摘Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.
基金financially supported by the National Natural Science Foundation of China(52162036 and 22378342)Key Project of Nature Science Foundation of Xinjiang(2021D01D08)+2 种基金Major Projects of Xinjiang(2022A01005-4 and 2021A01001-1)Key Research and Development Project of Xinjiang(2023B01025-1)the support from the Doctoral Student Special Program of the Young Talents Support Project of the China Association for Science and Technology in 2024。
文摘Practical Zn metal batteries have been hindered by several challenges,including Zn dendrite growth,undesirable side reactions,and unstable electrode/electrolyte interface.These issues are particularly more serious in low-concentration electrolytes.Herein,we design a Zn salt-mediated electrolyte with in situ ring-opening polymerization of the small molecule organic solvent.The Zn(TFSI)_(2)salt catalyzes the ring-opening polymerization of(1,3-dioxolane(DOL)),generating oxidation-resistant and non-combustible long-chain polymer(poly(1,3-dioxolane)(pDOL)).The pDOL reduces the active H_(2)O molecules in electrolyte and assists in forming stable organic–inorganic gradient solid electrolyte interphase with rich organic constituents,ZnO and ZnF_(2).The introduction of pDOL endows the electrolyte with several advantages:excellent Zn dendrite inhibition,improved corrosion resistance,widened electrochemical window(2.6 V),and enhanced low-temperature performance(freezing point=-34.9°C).Zn plating/stripping in pDOL-enhanced electrolyte lasts for 4200 cycles at 99.02%Coulomb efficiency and maintains a lifetime of 8200 h.Moreover,Zn metal anodes deliver stable cycling for 2500 h with a high Zn utilization of 60%.A Zn//VO_(2)pouch cell assembled with lean electrolyte(electrolyte/capacity(E/C=41 mL(Ah)^(-1))also demonstrates a capacity retention ratio of 92%after 600 cycles.These results highlight the promising application prospects of practical Zn metal batteries enabled by the Zn(TFSI)2-mediated electrolyte engineering.
基金supported by the National Natural Science Foundation of China(Nos.T2222013,52233008 and 52073203).
文摘Zwitterionic polymers are polymers containing a pair of oppositely charged groups in their repeating units,which facilitate the formation of a hydration layer on the surface through ionic solvation.This strong hydration results in the remarkable properties of zwitterionic polymer hydrogels,including antifouling,lubricating,and anti-freezing capabilities.Owing to these properties,zwitterionic polymer hydrogels have attracted notable attention in biomedical and engineering fields.However,the superhydrophilicity of zwitterionic polymer hydrogels renders them brittle and weak,considerably limiting their use in load-bearing applications.Thus,there is an urgent need to improve the mechanical properties of zwitterionic hydrogels.In this work,we systematically review mechanical enhancement strategies for zwitterionic polymer hydrogels.We cover strate-gies applicable to hybrid and pure high-strength zwitterionic polymer hydrogels.Additionally,we discuss the advantages and limitations of various strength enhancement strategies.
基金financially supported by the National Key R&D Program of China(No.2016YFC1100801)。
文摘Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important role.Herein a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and characterized.In combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction temperature.By changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were prepared.The kinetic and chain extension experiments were carried out to prove the"living"/controllable feature.And the NMR experiments were used to support the proposal of possible mechanism.
基金funded by the National Key R&D Program of China(No.2021YFA1501700)the Science and Technology Development Plan of Jilin Province(Nos.20230101042JC,20210201059GX)+2 种基金the National Natural Science Foundation of China,Basic Science Center Program(No.51988102)the National Natural Science Foundation of China(Nos.52203017,52073272 and 22293062)Bureau of International Cooperation Chinese Academy of Sciences(No.029GJHZ2023017MI)。
文摘A new strategy for the metal-free coordination–insertion ring-opening polymerization of tetrahydrofuran by the central metalloid Boron has been first identified.Bis(pentafluorophenyl)(phenoxy)borane was used as a catalyst for the polymerization reaction system.And polytetrahydrofuran with high molecular weight and narrow molecular weight distribution could be obtained.The proposed mechanism was studied by MALDI-TOF,ESI-MS and O-18 isotope labeling analyses as a metal-free coordination insertion mechanism.
基金financially supported by the National Natural Science Foundation of China(Nos.22271252 and 22201105)。
文摘Consisting of natural histidine residues,polyhistidine(PHis)simulates functional proteins.Traditional approaches towards PHis require the protection of imidazole groups before monomer synthesis and polymerization to prevent degradation and side reactions.In the contribution,histidine N-thiocarboxyanhydride(His-NTA)is directly synthesized in aqueous solution without protection.With the self-catalysis of the imidazole side group,the ring-closing reaction to form His-NTA does not require any activating reagent(e.g.,phosphorus tribromide),which is elucidated by density functional theory(DFT)calculations.His-NTA directly polymerizes into PHis bearing unprotected imidazole groups with designable molecular weights(4.2-7.7 kg/mol)and low dispersities(1.10-1.19).Kinetic experiments and Monte Carlo simulations reveal the elementary reactions and the relationship between the conversion of His-NTA and time during polymerization.Block copolymerization of His-NTA with sarcosine N-thiocarboxyanhydride(Sar-NTA)demonstrate versatile construction of functional polypept(o)ides.The triblock copoly(amino acid)PHis-b-PSar-b-PHis is capable to reversibly coordinate with transition metal ions(Fe^(2+),Co^(2+),Ni^(2+),Cu^(2+)and Zn^(2+))to form pH-sensitive hydrogels.
基金financially supported by the National Key R&D Program of China(No.2022YFC2805103)the National Natural Science Foundation of China(Nos.52022031 and 52263001)the Foundation from Qinghai Science and Technology Department(No.2022-ZJ-944Q)。
文摘Incorporation of acetal groups in the backbone is a potent strategy to create polymers that are cleavable or degradable under acidic conditions.We report here an in-depth study on the ring-closing-opening copolymerization of o-phthalaldehyde(OPA)and epoxide using Lewis pair type two-component organocatalysts for producing acetal-functionalized polyether and polyurethane.Notably,triethylborane as the Lewis acid,in comparison with tri(n-butyl)borane,more effectively enhances the polymerization activity by mitigating borane-induced reduction of the aldehyde group into extra initiating(borinic ester)species.Density functional theory(DFT)calculations present comparable energy barriers of OPA-epoxide cross-propagation and epoxide self-propagation,which is consistent with the experimental finding that an alternating-rich copolymer comprising mostly OPA-epoxide units but also epoxide-epoxide linkages is produced.In particular,when epoxide is added in a large excess,the product becomes a polyether containing acetal functionalities in the central part of the backbone and thus being convertible into polyurethane with refined acid degradability.
基金the National Natural Science Foundation of China(grant nos.52020105012 and 523B2025)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)the Analysis and Testing Center of HUST for the assistance in analysis and testing。
文摘Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteristics.However,their inherently low ion transport efficiency poses a major challenge for their application in LMBs.To address this issue,covalent organic framework(COF)with their ordered ion transport channels,chemical stability,large specific surface area,and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction.Here,we prepared an anionic COF,Tp Pa-COOLi,which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs.The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores,forming additional COF-polymer junctions that enhance ion transport pathways.The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix,preserving ion transport channels and facilitating ion transport across COF grain boundaries.By controlling variables to alter the crystallinity of Tp Pa-COOLi and the presence of-COOLi substituents,Tp Pa-COOLi with partial long-range order and-COOLi substituents exhibited superior electrochemical performance.This research demonstrates the potential in constructing high-performance SPEs for LMBs.
基金Funded by National Natural Science Foundation of China(No.51472166)。
文摘Bacterial cellulose(BC)was innovatively combined with zwitterionic copolymer acrylamide and sulfobetaine methacrylic acid ester[P(AM-co-SBMA)]to build a dual-network porous structure gel polymer electrolytes(GPEs)with high ionic conductivity.The dual network structure BC/P(AM-co-SBMA)gels were formed by a simple one-step polymerization method.The results show that ionic conductivity of BC/P(AM-co-SBMA)GPEs at the room temperature are 3.2×10^(-2) S/cm@1 M H_(2)SO_(4),4.5×10^(-2) S/cm@4 M KOH,and 3.6×10^(-2) S/cm@1 M NaCl,respectively.Using active carbon(AC)as the electrodes,BC/P(AM-co-SBMA)GPEs as both separator and electrolyte matrix,and 4 M KOH as the electrolyte,a symmetric solid supercapacitors(SSC)(AC-GPE-KOH)was assembled and testified.The specific capacitance of AC electrode is 173 F/g and remains 95.0%of the initial value after 5000 cycles and 86.2%after 10,000 cycles.
基金financially supported by the National Natural Science Foundation of China (Nos. 21734004 and 21674038)
文摘Highly potent ionic organocatalyst is developed for room-temperature controlled ring-opening polymerization(ROP)of lactones,includingδ-valerolactone,ε-caprolactone,andδ-hexalactone.The catalysts are prepared by simply mixing tetra-n-butyl ammonium hydroxide and a(thio)urea at elevated temperature under vacuum,and used in cooperation with an alcoholic initiator.The performance of the catalyst is readily adjusted and optimized through variation of the(thio)urea precursor,catalyst composition,and reaction condition.Urea-derived catalysts are generally superior to thiourea-derived ones.Provided with proper N-substituents,the catalyst affords both high polymerization efficiency and high selectivity for monomer enchainment over macromolecular transesterification,even at high monomer conversion and/or substantially extended reaction time.In addition to acidity,structural symmetry of the urea also proves decisive for the catalytic activity,which enables a catalyst-assisted proton transfer process for the ring-opening of lactone and thus provides a novel mechanistic insight for ROP catalyzed by hydrogen-bonding type bifunctional ionic organocatalysts.
基金This work was financially supported by the Special Fund for Major State Basic Research Project(G1999064801)the National Natural Science Foundation of China(Nos.20174033 and 20434020)
文摘In this paper,ring-opening polymerization of trimethylene carbonate(TMC)with rare earth(Nd,Y,La)ρ-tert- butylcalix[n]arene(n=4,6,and 8)complexes as catalysts has been studied.Poly(trimethylene carbonate)(PTMC)with M_v of 21,400 was produced by bulk polymerization under the conditions as follows:[TMC]_0/[Nd](molar ratio)=1000,80℃, 8 h.Mechanism study reveals that the polymerization proceeds via a coordination mechanism.
基金financially supported by the National Natural Science Foundation of China(Nos.21574124,51503203 and51233004)
文摘A series of zinc silylamido complexes based upon NNO tridentate enolic Schiff base framework have been synthesized and characterized. These complexes were tested for the ring opening polymerization of lactide and e-caprolactone, exhibiting notably high activity at ambient temperature, The influence of imine bridge length and substituents of diketone over the course of polymerization was investigated in details. Remarkably, 4a was confirmed to be a rare example of exceedingly active and robust zinc catalysts, achieving major transformation of lactide under extremely low loading （0.025 mol%） within 18 rain. The influence of various monomers as well as the polymerization mechanism have also been discussed.
基金supported by the National Natural Science Foundation of China.(Grant No.20174033 and 20254001)the Special Found for Major State Basic Research Project(Grant No.G1999064801)the Committee of Science and Technology of Zhejiang Province.
文摘The ring-opening polymerization of e-caprolactone (CL) initiated by novel single lanthanide tris(4-tert-butylphenolate)s [Ln(OTBP)3] is reported. Single-component La(OTBP)3 can effectively prepare polycaprolactone (PCL) with over 90% yield and viscosity average molecular weight about 60 x 10 under quite mild conditions: molar ratio of CL to initiator is 1000, 60 C, 2 h in toluene. Mechanism study indicates that the monomer inserts into the growing chain via the break of acyl-oxygen bond of CL.
基金financially supported by the National Natural Science Foundation of China (No. B040102)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials (Donghua University) (No. LK1501)Department of Science and Technology of Qingdao and Shandong Province (Nos. 159181jch and 2015GGX107015)
文摘Two types of bifunctional bis（salicylaldimine） ligands（syn-L and anti-L） were designed and synthesized to support bimetallic aluminum complexes. Owing to the rigid anthracene skeleton, syn-L and anti-L successfully locked two Al centers in close proximity（syn-Al2） and far apart（anti-Al2）, respectively. The distance between two Al centers in syn-Al2 was defined by X-ray diffraction as 6.665 ？, which is far shorter than that in anti-Al2. In the presence of stoichiometrical Bn OH, syn-Al2 and anti-Al2 were both efficient for ring-opening polymerization（ROP） of rac-LA with the former being more active. In the presence of excess Bn OH, syn-Al2 showed an efficient and immortal feature, consistent with high conversions, matched Mns, narrow molecular weight distributions and end group fidelity, while anti-Al2 had a much lower activity or even became entirely inactive due to rapid decomposition, indicated by in situ ～1H-NMR experiments of Al complexes with Bn OH.
基金partly supported by Grant-in-Aid for Scientific Research on Innovative Areas ("3D Active-Site Science", No. 26105003) from The Ministry of Education, Culture, Sports, Science and Technology (MEXT), JapanGrant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS, Nos. 15H03812, 18H01982)the Tokyo Metropolitan government (Tokyo Human Resources Fund for City Diplomacy) for pre-doctoral fellowship
文摘(Imido)vanadium(V)-alkylidene complexes of type V(CHSiMe3)(NR)(OR?)(PMe3)2 [R = Ad, C6H5, 2,6-Me2C6H3, 2,6-Cl2C6H3;R?= 2,6-Me2C6H3, 2,6-i Pr2C6H3, 2,6-F2C6H3, C6F5, C6Cl5] exhibited from moderate to remarkable catalytic activities for ringopening metathesis polymerization(ROMP) of norbornene(NBE). The catalytic activities were affected by the ligand substituents, and V(CHSiMe3)(N-2,6-Cl2C6H3)(OC6X5)(PMe3)2(X = F, Cl) demonstrated the exceptionally high catalytic activities for ROMP of NBE.The complexes polymerized cycloheptene(CHPE) and cis-cyclooctene(COE), and ROMP of COE by the OC6 Cl5 analogue proceeded in a living manner even at 80℃, and the activity increased with increasing the temperature up to 120 ℃. Highly active catalysts for ROMP of cyclic olefins(NBE, cyclopentene, and CHPE) can be generated in situ by premixing isolated V(CHSiMe3)(NC6F5)(O-2,6-iPr2C6H3)(PMe3)2 with 1.0 equiv. of C6F5OH or C6Cl5OH via immediate phenoxy exchange;the activity was affected by the kind of phenol added [TOF in the ROMPs of NBE: 4.62 × 10^4 min^–1(upon addition of C6F5OH) versus 37.3 min^–1(none)].
基金financially supported by the Science and Technology Commission of Shanghai Municipality(No.17JC1401200)
文摘Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalyst still remains a scientific challenge. Here we report our investigations into organocatalytic stereoselective ROP of rac-LA by utilizing novel bulky chiral and achiral N-heterocyclic carbenes（NHC）, 1,3-bis-（1′-naphthylethyl）imidazolin-2-ylidene. The effect of polymerization conditions（e.g. solvent, temperature, alcohol initiator） on ROP behavior by these bulky NHCs has been fully studied, leading to the formation of isotactic-rich stereoblock polylactide（Pi = 0.81） under optimized conditions with high activity（Conv. = 98% in 30 min） and narrow molecular weight dispersity（D = 1.05）.
