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Synthesis of poly(thiourethane-alt-thioester)by alternating ring-opening copolymerization of N-thiocarboxyanhydrides and episulfides
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作者 Wei Xiong Tianjun Yue +3 位作者 Haiwang Lai Chunyan Lyu Weimin Ren Hua Lu 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第9期3091-3097,共7页
Polythiourethanes(PTU)and polythioesters(PTE)derived from renewable sources are emerging sustainable polymers for their excellent degradability and recyclability.However,P(TU-alt-TE)copolymers have been rare and chall... Polythiourethanes(PTU)and polythioesters(PTE)derived from renewable sources are emerging sustainable polymers for their excellent degradability and recyclability.However,P(TU-alt-TE)copolymers have been rare and challenging to synthesize.Here,we report the efficient synthesis of novel P(TU-alt-TE)copolymers via the alternating copolymerization of N-thiocarboxyanhydrides(NTA)/episufides(ES)and provide mechanistic insight into the alternating chain propagation process via density functional theory(DFT)calculation.The incorporation of ESs into traditional peptide backbone is capable of adjusting the glass transition temperature below thermal decomposition temperature,which confers better thermal processability by regulating the rigidity of the backbone and the hydrogen bond interaction among the polymer chains.Crosslinked PTUs with tailored properties are accessible by altering the feeding ratio of NTAs and(bifunctional)ESs.Moreover,the thiourethane in the backbone can endow interesting underwater adhesion properties to the materials.Considering the broad scope of NTA and ES monomers,this method is expected to provide a promising and general route to a wide range of P(TU-alt-TE)copolymers with diverse properties. 展开更多
关键词 poly(thiourethane-alt-thioester) alternating ring-opening copolymerization N-thiocarboxyanhydrides episulfides
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Enantioselective Alternating Copolymerization of Propylene with Carbon Monoxide Using Cationic Palladium-Chiral Diphosphine Catalyst
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作者 Jian Chao YUAN Yu Hua ZHANG Shi Jie LU 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第6期519-522,共4页
Enantioselective alternating copolymerization of carbon monoxide with propylene was carried out using palladium catalyst modified by 1,4-3,6-dianhydro-2,5-dideoxy-2,5-bis (diphenylphosphino)-L-iditol (DDPPI). The chir... Enantioselective alternating copolymerization of carbon monoxide with propylene was carried out using palladium catalyst modified by 1,4-3,6-dianhydro-2,5-dideoxy-2,5-bis (diphenylphosphino)-L-iditol (DDPPI). The chiral diphosphine was proved to be effective at enantioselective copolymerization. Optical rotation, elemental analysis, H-1, C-13-NMR and IR spectra showed that the copolymer was optically active, isotactic, alternating poly(1,4-ketone) structure. 展开更多
关键词 Palladium catalyst chiral ligand enantioselective alternating copolymerization isotactic copolymer optical activity
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Study on Alternating Copolymerization of Polyester-amides
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作者 魏文良 李建梅 朱方亮 《Journal of Donghua University(English Edition)》 EI CAS 2002年第4期87-91,共5页
The preparing methods, choice of catalysts and reaction kinetics of one of the monomers, diesteramide(DEA), of polyester-amides were investigated in details. The chemical structure of DEA was analyzed. And the Polyest... The preparing methods, choice of catalysts and reaction kinetics of one of the monomers, diesteramide(DEA), of polyester-amides were investigated in details. The chemical structure of DEA was analyzed. And the Polyester-amides (PEA) were obtained by melt copolymerization with DEA. It is shown that DEA can be synthesized by DMT and hexamethylene diamine with the catalyst EX - 1 or EX - 2. The relationship between reaction rate of synthesizing monomer and concentration of hexamethylene diamine is first order kinetic relation. 展开更多
关键词 polyester-amides REACTION kinetics alternating copolymerization STRUCTURE
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Ring-opening Copolymerization of Adipic Anhydride and Propylene Oxide Catalyzed by Yttrium Triflates
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作者 CHEN Feng ZHU Wei-pu SHEN Zhi-quan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第3期397-399,共3页
The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly(propylene adipate) could be synthesized by controlling the copolymerization condi... The ring-opening copolymerization of adipic anhydride with propylene oxide was carried out with yttrium triflates as a catalyst. Poly(propylene adipate) could be synthesized by controlling the copolymerization conditions. The copolymerization procedure was tracked by ^1H NMR analyses. 展开更多
关键词 Adipic anhydride Propylene oxide POLYESTER ring-opening copolymerization Yttrium triflate
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STUDY ON CATIONIC RING-OPENING COPOLYMERIZATION OF 1,4-ANHYDRO-2,3-DI-O-BENZYL-α-D-RIBOPYRANOSE WITH 1,4-ANHYDRO-2,3-O-ISOPROPYLIDENE-α-D-RIBOPYRANOSE
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作者 吴承佩 潘才元 瓜生敏之 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1997年第3期282-288,共7页
Cationic ring-opening copolymerization of 1, 4-anhydro-2, 3-O-isopropylidene-α-D-ribo-pyranose (AIRP) with 1,4-anhydro-2,3-di-O-benzyl-α-D-ribopyranose (ADBR) preparedfrom D-ribose was studied. Copolymerization usin... Cationic ring-opening copolymerization of 1, 4-anhydro-2, 3-O-isopropylidene-α-D-ribo-pyranose (AIRP) with 1,4-anhydro-2,3-di-O-benzyl-α-D-ribopyranose (ADBR) preparedfrom D-ribose was studied. Copolymerization using SbCl_5 or BF_3 OEt_2 as catalyst atlow temperature gave stereoregular (1→4)β-D-ribofuranan (C-1 and C-4 ring cleavagesee Scheme 1) or (1→5) α-D-ribofuranan (C-1 and C-5 ring cleavage) respectively. Theeffects of catalysts, reaction time and temperatures on yield and stereoregularity of the ob-tained polymers were studied. Polymers were characterized by molecular weight, ~1HNMR,^(13)CNMR and optical rotation. 展开更多
关键词 1 4-Anhydroribose derivatives Cationic ring-opening copolymerization Specific rotation Lewis acid catalysts
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Facile Synthesis of Polyisothioureas via Alternating Copolymerization of Aziridines and Isothiocayanates
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作者 Hao-Tian Zhang Ming-Xin Niu +2 位作者 Qi Zhang Chen-Yang Hu Xuan Pang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第3期292-298,I0005,共8页
Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits... Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits a number of interesting properties. However, there is no access to synthesizing well-defined polyisothiourea, and currently isothiourea-containing polymers are mainly prepared by immobilizing onto other polymer's side chain. Herein, we report the first facile synthesis of polyisothioureas via alternating copolymerization of aziridines and isothiocayanates. Mediated by the catalytic system of phosphazene superbases/alcohol, a broad scope of aziridines and isothiocayanates could be transformed into polyisothioureas with adjustable substitutions(11 examples). The structures of obtained polyisothioureas were fully characterized with ^(1)H-NMR, ^(13)C-NMR, and ^(1)H-^(13)C HMBC NMR. Moreover, the polyisothioureas show tunable thermal properties depending on substitutions on the isothiourea linkages. The novel structure of these polyisothioureas will enable a powerful platform for the discovery of nextgeneration functional plastics. 展开更多
关键词 Polyisothioureas alternative copolymer AZIRIDINES Isothiocayanates
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Highly active organocatalyst from a trivalent phosphazenium salt for ring-opening copolymerization of epoxides and cyclic anhydrides enhanced by hydrogen bonding interactions
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作者 Chunhuan Jiang Junqi Wang +4 位作者 Xiaoyu Liu Xiaoxia You Ronglin Zhong Chuanli Ren Zhibo Li 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第9期3111-3120,共10页
It is highly desirable to develop simple organocatalysts for the controlled ring-opening alternating copolymerization(ROAC)of epoxides and cyclic anhydrides,leading to high molecular weight polyesters.Hence,a phosphaz... It is highly desirable to develop simple organocatalysts for the controlled ring-opening alternating copolymerization(ROAC)of epoxides and cyclic anhydrides,leading to high molecular weight polyesters.Hence,a phosphazenium salt,namely tri[tris(dimethylamino)phosphoranylidenamino]phosphonium chloride(P_(4)^(+)Cl^(-)),is developed as a catalyst for the ROAC of epoxides and cyclic anhydrides.Surprisingly,the combination of P_(4)^(+)Cl^(-)with a protonic initiator,such as 1,4-benzenedimethanol(BDM)exhibited high efficiency in the copolymerization of propylene oxide(PO)and phthalic anhydride(PA).This led to the production of polyester with an exceptional high molecular weight(M_n)of up to 126 k Da,which represented a rare example of poly(PO-alt-PA)with Mnsurpassing 100 k Da.Note that the core P atom is trivalent status and the tris[tris(dimethylamino)]phosphoranyl group will share one proton in the P_(4)^(+)Cl^(-)salt.Once combined with protonic species,the P_(4)^(+)Cl^(-)will not only serve as a proton acceptor but also as a hydrogen bonding donor for the cyclic anhydrides.Therefore,it was assumed that the P_(4)^(+)plus proton served dual role in mimic of base/urea pair to effectively catalyze ROAC,which was supported by density functional theory(DFT)calculations. 展开更多
关键词 ring-opening copolymerization ORGANOCATALYST EPOXIDES cyclic anhydrides phosphazenium salt
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Ring-Opening Copolymerization of Biorenewable -Caprolactone with trans-Hexahydro-(4,5)-benzofuranone toward Closed-Loop Recyclable Copolyesters and Their Application as Pressure- Sensitive Adhesives
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作者 Haining Niu Liying Wang +3 位作者 Zihan Zhang Yalei Liu Yong Shen Zhibo Li 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第17期2035-2042,共8页
Copolymerization as an efficient strategy can provide an opportunity to create new closed-loop recyclable polymeric materials with tailored properties that are generally inaccessible to the individual homopolymers.In ... Copolymerization as an efficient strategy can provide an opportunity to create new closed-loop recyclable polymeric materials with tailored properties that are generally inaccessible to the individual homopolymers.In this contribution,the bulk ring-opening copolymerization of bio-renewable-caprolactone and trans-hexahydro-(4,5)-benzofuranone was achieved to produce closed-loop recyclable copolyesters by using an organobase/urea binary catalyst at room temperature.The obtained copolyesters exhibited composition-dependent thermal properties.Remarkably,the obtained copolyesters were able to depolymerize back to recover the corresponding monomers under mild conditions. 展开更多
关键词 Recyclable polymers ring-opening polymerization copolymerization Pressure-sensitive adhesives Aliphatic polyesters
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Fluorescence Spectra of Model Compounds for Light-emitting Alternating Copolymers in Heterogeneous Environments
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作者 Jun Lin YANG Hong Zhen LIN +1 位作者 Min ZHENG Feng Lian BAI 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第4期369-372,共4页
In this paper, the fluorescence spectra of model compounds of light-emitting alternating copolymers. M (TPA-PPV) and M (TPA-PAV) (Scheme 1) were studied and the effect of KNO3 on the interaction between model compound... In this paper, the fluorescence spectra of model compounds of light-emitting alternating copolymers. M (TPA-PPV) and M (TPA-PAV) (Scheme 1) were studied and the effect of KNO3 on the interaction between model compounds and ionic micelle-watts interface was also investigated. It is found that (I) The fluorescence changes of M (TPA-PPV) are related to the state of CTAB and SDS solution. (II)Aggregated state can be formed in M (TPA-PAV) solution at low concentration of CTAB. (III) Higher concentration of KNO3 may affect the interaction between model compounds and ionic micelle-water interface. 展开更多
关键词 alternating copolymer charge transfer ionic micelle-water interface salt effect cetyl-trimethylammonium bromide sodium dodecylsulfate
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Synthesis and Photophysical Properties of Fluorene or Carbazole-Based Alternating Copolymers Containing Si and Ethynylene Units in the Main Chain
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作者 Naofumi Naga Nanae Tagaya Haruhiko Tomoda 《International Journal of Organic Chemistry》 CAS 2016年第1期20-30,共11页
Alternating copolymerization of 9,9-dihexyl-2,7-dibromofluorene, N-hexyl-2,7-dibromocarbazole (HCz) with diethynyldimethylsilane, diethynyldiphenylsilane, has been investigated using Sonogashira coupling reaction. Pho... Alternating copolymerization of 9,9-dihexyl-2,7-dibromofluorene, N-hexyl-2,7-dibromocarbazole (HCz) with diethynyldimethylsilane, diethynyldiphenylsilane, has been investigated using Sonogashira coupling reaction. Photophysical properties of the resulting copolymers were investigated with UV-Vis absorption and photoluminescence spectroscopy. All the copolymers in chloro-form solution showed absorption peaks at 270 - 280 nm with shoulder peaks at around 380 nm derived from π-π* transition or intra-molecular charge transfer through σ-π moiety, respectively. The chloroform solutions of the copolymers showed broad emission peaks at 415 - 425 nm. The emission wave lengths of the copolymers in the solid state (cast film) detected at 360 - 385 nm were remarkably blue-shifted in comparison with those in the chloroform solutions. Hydrosilylation reaction of the copolymers with 1,4-bis(dimethylsilyl)benzene yielded networked copolymers soluble in chloroform, indicating formation of branching polymers. The chloroform solutions of the HCz-based networked copolymers showed bimodal emission derived from new highly energy states in the σ-π conjugation. 展开更多
关键词 FLUORENE CARBAZOLE alternating copolymer Si-Ethynylene Photophysical Property Network Polymer
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Recyclable polymer functionalization via end-group modification and block/random copolymerization 被引量:2
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作者 Yihuan Liu Jiaqi Wu +5 位作者 Huan Liang Zhao Jin Lianzhu Sheng Xin Hu Ning Zhu Kai Guo 《Green Energy & Environment》 SCIE CSCD 2021年第4期578-584,共7页
Recyclable polymers offer a great opportunity to address the environmental issues of plastics.Herein,functionalization of recyclable polymers,poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),were reported via... Recyclable polymers offer a great opportunity to address the environmental issues of plastics.Herein,functionalization of recyclable polymers,poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),were reported via end-group modifications and block/random copolymerizations.Di-n-butylmagnesium was selected to catalyze ring-opening polymerization(ROP)of(R)-M in the presence of a series of functional alcohols as the initiators.Block/random copolymerizations of(R)-M andε-caprolactone(ε-CL),L-lactide(L-LA)and trimethylene carbonate(TMC)were performed to control the onset decomposition temperature(T_(d)),melting temperature(T_(m))and glass transition temperature(T_(g)).These functionalized recyclable polymers would find broad applications as the sustainable plastics. 展开更多
关键词 Recyclable polymers End-group modification copolymerization ring-opening polymerization
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SYNTHESIS, CHARACTERIZATION AND RING-OPENING POLYMERIZATION OF CYCLIC (ARYLENE PHOSPHONATE) OLIGOMERS 被引量:2
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作者 陈天禄 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2004年第1期83-89,共7页
A series of cyclic (arylene phosphonate) oligomers were prepared by reaction of phenylphosphonic dichloride (PPD) with various bisphenols under pseudo-high dilution conditions via interfacial polycondensation. The yie... A series of cyclic (arylene phosphonate) oligomers were prepared by reaction of phenylphosphonic dichloride (PPD) with various bisphenols under pseudo-high dilution conditions via interfacial polycondensation. The yield of cyclic (arylene phosphonate) oligomers is over 85% by using hexadecyltrimethylammoniun bromide as phase transfer catalyst (PTC) at 0 'C . The structures of the cyclic oligomers were confirmed by a combination of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and IR analysis. These cyclic oligomers undergo facile ring-opening polymerization in the melt by using potassium 4,4'-biphenoxide as the initiator to give linear polyphosphonate. Free-radical ring-opening polymerization of cyclic(arylene phosphonate) oligomers containing sulfur linkages was also performed in the melt using 2,2'-dithiobis(benzothiazole) (DTB) as the initiator at 270 °C and the resulting polymer had a Mw, of 8 × 103 with a molecular weight distribution of 4. Ring-opening copolymerization of these cyclic oligomers with cyclic carbonate oligomers was also achieved. The average molecular weight of the resulting copolymer is higher than the corresponding homopolymer and the thermal stability of the copolymer is better than the corresponding homopolymer. 展开更多
关键词 Cyclic(arylene phosphonate) oligomer ring-opening polymerization copolymer
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CONTROLLED RADICAL COPOLYMERIZATION OF STYRENE AND MALEIC ANHYDRIDE UNDER GAMMA RADIATION IN THE PRESENCE OF BENZYL DITHIOBENZOATE 被引量:1
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作者 De-cheng Wu Ying-fang Zou Cai-yuan Pan Department of Polymer Science and Engineering University of Science and Technology of China, Hefei 230026, China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2002年第6期525-530,共6页
The copolymerization of styrene (St) with maleic anhydride (MAh) under gamma radiation at room temperature in the presence of benzyl dithiobenzoate (BDTB) was found to display 'living' nature evidenced by cons... The copolymerization of styrene (St) with maleic anhydride (MAh) under gamma radiation at room temperature in the presence of benzyl dithiobenzoate (BDTB) was found to display 'living' nature evidenced by constant concentration of chain radicals during the copolymerization, linear evolution of molecular weights with conversion and narrow molecular weight distribution (M-w/M-n = 1.23-1.35). The compositional analysis and the sequence structural information of the copolymers obtained from DEPT (Distortionless Enhancement by Polarization Transfer) experiments demonstrate that the copolymers obtained also possess strictly alternating structure. 展开更多
关键词 controlled radical polymerization alternating copolymer maleic anhydride STYRENE
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Alternating Copolymerization of Epoxides and Isothiocyanates to Diverse Functional Polythioimidocarbonates and Related Block Polymers 被引量:1
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作者 Xiao-Feng Zhu Xin-Yu Lu +5 位作者 Cheng-Kai Xu Yu-Bo Fang Guan-Wen Yang Wei Li Jingdai Wang Guang-Peng Wu 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2023年第23期3311-3318,共8页
Synthesis of diverse polythioimidocarbonates via ring-opening copolymerization of epoxides and isothiocyanates catalyzed by organoboron catalyst was reported herein.Both aromatic and aliphatic isothiocyanates underwen... Synthesis of diverse polythioimidocarbonates via ring-opening copolymerization of epoxides and isothiocyanates catalyzed by organoboron catalyst was reported herein.Both aromatic and aliphatic isothiocyanates underwent successful copolymerization with terminal and internal epoxides,allowing for the precise tuning of the performance of the resultant copolymers over a broad range.The wide scope of available isothiocyanates and epoxides enables the direct construction of sulfur-containing functional polymers featuring both high glass transition temperature and refractive index.Additionally,it was observed that aromatic isothiocyanates polymerize much faster than aliphatic ones,and the reactivity difference facilitated the one-step synthesis of block polymers from mixed aromatic isothiocyanates,aliphatic isothiocyanates and epoxides due to the preferential incorporation of aromatic isothiocyanates over the aliphatic analogues during their alternating copolymerization with epoxides.The produced polythioimidocarbonates can be used as positive resists for electron beam lithography(sensitivity of 130μC/cm^(2) and contrast of 1.53 for poly(CHO-alt-EITC)).Coupling with their high refractive index(1.58—1.68),polythioimidocarbonates might find functional applications in optics.These results render ring-opening copolymerization of epoxides and isothiocyanates a facile route to enrich functional polymer library. 展开更多
关键词 ring-opening copolymerization Metal-free catalysis Sulfur-containing polymers Block polymers Electron beam lithography High refractive index
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Potassium Acetate/18-Crown-6 Pair:Robust and Versatile Catalyst for Synthesis of Polyols from Ring-Opening Copolymerization of Epoxides and Cyclic Anhydrides
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作者 Xiaoqing Dou Xiao-Hui Liu +1 位作者 Bin Wang Yue-Sheng Li 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2023年第1期83-92,共10页
Efficient synthesis of polyester polyols with tunable molecular weight and microstructures from cyclic anhydride/epoxide mixtures by taking advantage of chain transfer reaction remains a great challenge,because most o... Efficient synthesis of polyester polyols with tunable molecular weight and microstructures from cyclic anhydride/epoxide mixtures by taking advantage of chain transfer reaction remains a great challenge,because most of the catalysts exhibit poor tolerance to chain transfer agent(CTA).In this contribution,we demonstrated that potassium acetate(KOAc)and 18-crown-6(18-C-6)combination has great potential in the synthesis of diverse polyester polyols with controllable molecular weight and high-end group fidelity.Com-pared with KOAc,KOAc/18-C-6 pair could induce a much faster chain transfer between the active and dormant chains,and thus produce polyester polyols with narrow and monomodal distribution.In addition,polyester polyols could be efficiently prepared in laboratory by using commercially available cyclic anhydride without further purification(containing about 2%diacid residual as CTA)with an extremely low catalyst loading([catalyst pair]:[anhydride]:[epoxide]=1:50000:250000,[catalyst pair]=0.0004 mol%).KOAc/18-C-6 could also promote the self-switchable copolymerization of cyclic anhydride/epoxide/cyclic ester mixtures.Ring-opening copolymerization of cyclic ester was initiated automatically after the full conversion of cyclic anhydride,finally producing polyester polyols with ABA-type block structure. 展开更多
关键词 ring-opening polymerization Macrocyclic ligands Block copolymer Cyclic Anhydride EPOXIDE
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Conventional Radical and RAFT Alternating Copolymerizations of Hydroxyalkyl Vinyl Ethers and Dialkyl Maleates
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作者 Yan-Xin Zhang Dong Chen +2 位作者 Gao-Fei Hu Yu-Hong Ma Wan-Tai Yang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第12期1856-1867,I0006,共13页
The alternating copolymerization of hydroxyalkyl vinyl ethers and dialkyl maleates is investigated by conventional radical polymerization and reversible addition-fragmentation chain transfer polymerization(RAFT).The i... The alternating copolymerization of hydroxyalkyl vinyl ethers and dialkyl maleates is investigated by conventional radical polymerization and reversible addition-fragmentation chain transfer polymerization(RAFT).The influence of comonomer structure,comonomer feeding ratios,and monomer concentrations on the copolymerization and the copolymer structure have been investigated systematically.With 2-hydroxyethyl vinyl ether(HEVE)and dimethyl maleates(DMM)as comonomers,a well-defined alternating copolymer is prepared with M_(n)=3400 and M_(w)/M_(n)=1.93 up to 71.6% monomer.The alternating sequential chain structure of the copolymers has been proved by both NMR and matrixassisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS).The experimental reactivity ratios and theoretical calculated highest occupied molecular orbital and the lowest unoccupied molecular orbital of vinyl ethers and alkyl maleates support that these monomer pairs have tendency to form alternating copolymers.With 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)carbamodithioate as the RAFT agent,the molecular weight of HEVE and DMM copolymer increases with the monomer conversion,demonstrating a controlled radical polymerization feature with well-controlled molecular weight and relatively narrower molecular weight distribution.With alternating copolymer of HEVE and DMM as macro-CTA(M_(n)=5200 and M_(w)/M_(n)=1.46),both the chain extension with HEVE and DMM(M_(n)=10400 and M_(w)/M_(n)=1.72)and block copolymerization with vinyl acetate have been successfully achieved(M_(n)=8500 and M_(w)/M_(n)=1.52). 展开更多
关键词 Radical polymerization Vinyl ethers MALEATES alternating copolymer RAFT polymerization
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有机磷腈盐/三乙基硼二元催化体系协同催化环氧化物与二氢香豆素的开环交替共聚
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作者 姜春环 王俊麒 +3 位作者 刘晓雨 杨烨 任传利 李志波 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2024年第7期166-172,共7页
通过使用有机磷腈盐催化剂三[三(二甲氨基)亚氨基]氯化磷(P_(4)^(+)Cl^(-))与三乙基硼(TEB)组成的二元协同催化体系,实现了3,4-二氢香豆素(DHC)与多种环氧化物的开环交替共聚.系统考察了聚合温度和催化剂用量等因素对聚合活性和选择性... 通过使用有机磷腈盐催化剂三[三(二甲氨基)亚氨基]氯化磷(P_(4)^(+)Cl^(-))与三乙基硼(TEB)组成的二元协同催化体系,实现了3,4-二氢香豆素(DHC)与多种环氧化物的开环交替共聚.系统考察了聚合温度和催化剂用量等因素对聚合活性和选择性的影响.研究结果表明,通过优化聚合反应条件,P_(4)^(+)Cl^(-)/TEB催化体系对多种环氧化物与DHC的开环交替共聚表现出较高的催化活性和选择性,避免了分子内酯交换等副反应.研究了反应动力学,利用核磁共振氢谱(^(1)H NMR),体积排阻色谱(SEC)和基质辅助激光解吸/电离时间飞行质谱(MALDI-TOF-MS)对聚合物结构进行表征,结果表明产物为端基明确、分子量可控的高度交替结构的醚酯共聚物. 展开更多
关键词 磷腈盐 有机催化 酚内酯 开环交替共聚 聚酯
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Synthesis and Characterization of Amphiphific Block Copolymer Containing PVP and Poly(5-benzyloxytrimethylene carbonate) 被引量:3
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作者 Ying Xia WANG Feng HE Ren Xi ZHUO 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第2期239-242,共4页
Amphiphilic copolymer of 5-benzyloxytrimethylene carbonate (BTMC) with poly (vinyl pyrrolidone) (PVP) was successfully synthesized using immobilized porcine pancreas lipase (IPPL) or SnOct2 as catalyst. Hydrox... Amphiphilic copolymer of 5-benzyloxytrimethylene carbonate (BTMC) with poly (vinyl pyrrolidone) (PVP) was successfully synthesized using immobilized porcine pancreas lipase (IPPL) or SnOct2 as catalyst. Hydroxyl terminated PVP, synthesized with 2-mercaptoethanol as a chain transfer reagent, was employed as a rnacroinitiator. The resulting copolymers were characterized by GPC, ^1H NMR and IR. Increasing the BTMC/PVP-OH feed ratio ([B]/[P]) resulted in the increase of Mn of corresponding copolymers and the decrease of Mw/Mn. Immobilized enzyme has comparable catalytic activity to SnOct2 for the copolymerization. 展开更多
关键词 Amphiphilic copolymer end-functionalized PVP 5-benzyloxytrimethylene carbonate immobilized enzyme ring-opening polymerization macroinitiator.
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Epoxidation of Styrene-Isoprene-Styrene Block Copolymer and Research on Its Reaction Mechanism 被引量:2
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作者 李红强 曾幸荣 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第3期403-407,共5页
Styrene-isoprene-styrene(SIS) block copolymer was modified into epoxidized styrene-isoprene-styrene(ESIS) block copolymer with performic acid generated in situ from hydrogen peroxide and formic acid.The structure ... Styrene-isoprene-styrene(SIS) block copolymer was modified into epoxidized styrene-isoprene-styrene(ESIS) block copolymer with performic acid generated in situ from hydrogen peroxide and formic acid.The structure and property of ESIS were characterized by Fourier transform infrared(FT-IR) spectroscopy,gel permeation chromatography(GPC),thermogravimetric/differential thermogravimetric(TG/DTG),melt flow rate(MFR) and dynamic mechanical analysis(DMA),and the reaction mechanism in the process of epoxidation was analyzed.The results showed that C=C double bonds of 1,4-structure were more active than that of 3,4-structure in polyisoprene chains.With epoxidation reaction proceeding,the whole tendency of molecular weight increased and molecular weight distribution widened,and MFR firstly increased and latterly decreased.The heat resistance of ESIS was superior to that of SIS.When SIS was changed into ESIS with 15.3% of mass fraction of epoxide groups,Tg of polyisoprene chains increased from-45.3 ℃ to 10.9 ℃.In the earlier period of epoxidation,some molecular chains ruptured and new substances with low molecular weight formed.However,in the latter period,crosslinking reaction between molecular chains which was initiated by epoxide groups or C=C double bonds occurred and crosslinked insoluble substances came into being. 展开更多
关键词 styrene-isoprene-styrene block copolymer EPOXIDATION ring-open reaction mechanism
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SYNTHESIS AND CHARACTERIZATION OF POLY(AMINO ACID-UREA)S COMPRISING NOVEL TRIBLOCK COPOLYMERS OF POLY(TETRAHYDROFURAN)AND POLY(γ-BENZYL L-GLUTAMATE)S 被引量:1
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作者 冯增国 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第3期317-325,共9页
A kind of novel triblock copolymers of poly(γ-benzyl L-glutamate)-b-poly(tetrahydrofuran)-b-poly(γ-benzyl L-glutamate)s(PBLG-b-PTHF-b-PBLG)was synthesized by using bis(3-aminopropyl)terminated polytetrahydrofuran to... A kind of novel triblock copolymers of poly(γ-benzyl L-glutamate)-b-poly(tetrahydrofuran)-b-poly(γ-benzyl L-glutamate)s(PBLG-b-PTHF-b-PBLG)was synthesized by using bis(3-aminopropyl)terminated polytetrahydrofuran to initiate the ring-opening polymerization ofγ-benzyl L-glutamate N-carboxyanhydride(BLG-NCA).The corresponding multiblock poly(amino acid-urea)s were prepared in one-pot protocol from the chain extension of PBLG-b-PTHF-b-PBLG with MDI.The resulting triblock and multiblock copolymers were characterized by FTIR,~1H-NMR,^(13)C-NMR and GPC techniques.It is demonstrated that the chain extension has taken place to give rise to the copolymers with the well-defined block composition and narrow molecular weight distribution.A distinct T_g arising from the hard-segments was observed in all the copolymers.Their mechanical properties showed an increasing trend with the molecular weight enhancement of the prepolymers. 展开更多
关键词 Polyurethane POLYPEPTIDE Triblock copolymer ring-opening polymerization.
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