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Phosphine/Benzocyclone-based Neutral Nickel Catalysts for Ethylene polymerization and Copolymerization with Polar Monomers

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Chinese Journal of polymer Science 2024年第2期42卷 202-212,I0007页

作者： Fei Wang Li Pan Vladislav A.Tuskaev Svetlana Ch.Gagieva Yue-Sheng Li Tianjin Key lab of Composite&Functional Materials School of Material Science and EngineeringTianjin UniversityTianjin300072China Department of Chemistry Lomonosov Moscow State UniversityRussian Federation InstitutionLeninskie Gory 1Moscow119991Russian Federation A N Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesVavilova st.28Moscow119991Russian Federation

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts(Ni1: Ar = Ph;Ni2: Ar = 2-(C_(6)H_(5))C_(6)H_(4);Ni3: Ar = 2-[2',6'-(Me O)_(2)-C_(6)H3]C_(6)H_(4)) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes Ni2 and Ni3 contributed to high catalytic activities(up to 7.24×10^(6) and 9.04×10^(6)g·mol Ni^(-1)·h^(-1), respectively), and produced high-molecular-weight polyethylene(Mw up to 545.7 k Da). Complex Ni3 exhibited high activities for ethylene polymerization at the level of 10^(6) g·mol Ni^(-1)·h^(-1) across a wide range from 30 ℃ to 120 ℃, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights(Mw up to 80.5 k Da) and high polar monomer incorporation(up to 8.2 mol%). Microstructure analyses revealed that the introduction of large sterically hindered substituents facilitated the incorporation of polar functional units into the polymer backbone. This study demonstrates the potential of these nickel-based catalysts for efficient copolymerization of olefin with polar monomers.

关键词： Neutral nickel catalyst Ethylene polymerization Copolymerization Polar acrylate monomers

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Investigations on the adsorbents for uremic middle molecular toxins (Ⅱ)——Influences of crosslinking agent chain length on the adsorption capacities of crosslinked chitosan adsorbents

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Science China Chemistry 2001年第5期44卷 457-464页

作者：王虹袁直刘晓航滕欣莲何炳林 State Key lab. of Functional polymer Institute of Polymer Chemistry Nankai University Tianjin 300071 China

Chitosan resins, which clinically served as adsorbents in hemoperfusion therapy, were prepared with reversed-phase suspension methodology using three differently structured crosslinking agents, methanal, glyoxal and glutaraldehyde. And the glyoxal and glutaraldehyde crosslinked chitosan resins were reduced with NaBH4 afterwards. By analyzing the results from FTIR and SEM, it was found that the reduction treatment to the adsorbents efficiently improved the chemical stability of these chitosan resins, and the shifts in crosslinking agents exerted influences over the morphologies of the adsorbents obviously. After being put to use in the adsorption tests upon some model uremic middle molecular toxins and BSA in vitro, all three adsorbents demonstrated a fairly realistic adsorption capability to the model toxins but little to BSA. And the adsorption process reached the equilibrium in a clinically qualified short time. But the adsorption capacities of these adsorbents to the model toxins were quite different.

关键词： hemoperfusion uremia middle molecular toxins adsorbent crosslinked chitosan.

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Topological Confinement in Reversibly Interlocked polymer Networks

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Chinese Journal of polymer Science 2024年第2期42卷 133-140,I0004页

作者： Wan-Ting Dai Zhen-Hua Xie Yu-Bin Ke Yang You Min-Zhi Rong Ming-Qiu Zhang Key laboratory for polymeric Composite and Functional Materials of Ministry of Education GD HPPC LabIGCMESchool of ChemistrySun Yat-sen UniversityGuangzhou510275China Spallation Neutron Source Science Center China Spallation Neutron SourceDongguan523803China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China College of Materials and Metallurgy Guizhou UniversityGuiyang550025China

Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.

关键词： Reversibly interlocked polymer networks Small angle X-ray scattering Small-angle neutron scattering Topological confinement

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Mesoporous polymers:soft-template self-assembly synthesis and applications

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Science China Chemistry 2024年第5期67卷 1442-1464页

作者： Facai Wei Tingting Zhang Jianwei Fu Chengbin Jing Jiangong Cheng Shaohua Liu State Key laboratory of Precision Spectroscopy Engineering Research Center of Nanophotonics&Advanced Instrument(Ministry of Education)School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450052China State Key lab of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China

Mesoporous polymers combine the advantages of polymer materials(abundant polar functional groups,lightweight,flexibility,and processability)and mesoporous structures(high specific surface area,adjustable pore structure,and large pore volume);hence,they have great application potential in sensing,adsorption,catalysis,energy storage,biomedicine,***,developing advanced synthetic strategies for mesoporous polymers and investigating their intrinsic applications have become hot research ***-template-based self-assembly is regarded as a promising approach for synthesizing mesoporous *** work reviews recent progress in the synthetic strategy for producing various mesoporous polymers using soft-template selfassembly,focusing on the synthesis of conductive polymers,phenol-based polymers,and resin-based polymers and their potential ***,perspectives on future applications of mesoporous polymers,along with a few challenges that need to be resolved,are also discussed in this review.

关键词： mesoporous polymer porous material self-assembly soft templates interface synthesis

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The Crystallization Behavior of L-Poly(lactic acid)/Polypropylene Blends:The Acceleration for Both L-Poly(lactic acid)and Polypropylene

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Chinese Journal of polymer Science 2024年第6期42卷 775-786页

作者： Shuang-Cheng Li Wei-Jia Zhou Wen-Jie Wu Jun Shao Shui-Liang Chen Hao-Qing Hou Sheng Xiang College of Chemistry&Chemical Engineering and Nanofiber Engineering Center of Jiangxi Province Jiangxi Normal UniversityNanchang330022China National Engineering Research Center for Carbohydrate Synthesis/Key lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022China Wenzhou Institute University of Chinese Academy of SciencesWenzhou325001China

For a polymer/polymer dismissible blend with two crystallizable components,the crystallization behavior of different components and the reciprocal influences between different crystals are interesting and important,but did not investigate in *** this study,the L-poly(lactic acid)/polypropylene(PLLA/PP)blends with different weight ratios were prepared by melt mixing and the crystallization behavior of the blends were *** showed that the crystalline structures of PLLA and PP were not altered by the *** the crystallization of PLLA,both the diffusion of chain segments and crystallization rate were enhanced under the existence of PP *** the crystallization of PP,its crystallization rate was depressed under the existence of amorphous PLLA molecular *** the PP crystallized from the existence of PLLA crystals,although the diffusion rate of PP was reduced by PLLA crystals,the nucleation positions were obviously enhanced,which accelerated the formation of PP *** investigation would supply more basic data for the application of PLLA/PP blend.

关键词： L-poly(lactic acid) Polypropylene Blends Crystalization behavior Crystallization acceleration

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Thermoresponsive dendronized copolymers for protein recognitions based on biotin-avidin interaction

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Chinese Chemical Letters 2017年第4期28卷 832-838页

作者： Chunhua Zhou Mona A.Abdel-Rahman Wen Li Kun Liu Afang Zhang Department of polymer Materials Shanghai University Chemistry Department Polymer Lab.109Faculty of ScienceAssiut University

Thermoresponsive biotinylated dendronized copolymers carrying dendritic oligoethylene glycol（OEG）pendants were prepared via free radical polymerization,and their protein recognitions based on biotin-avidin interaction *** first（PG1） and second generation（PG2） dendronized copolymers were designed to examine possible thickness effects on the interaction between biotin and *** from the outstanding thermoresponsive properties from OEG dendrons,these biotinylated cylindrical copolymers show characteristic thermoresponsive behavior which provides an envelope to capture avidin through switching temperatures above or below their phase transition temperatures（T_（cp）s）.Thus,the recognition of polymer-supported biotin with avidin was investigated with UV/vis spectroscopy and dynamic laser light *** contrast to the case for PG1,the increased thickness for copolymer PG2 hinders partially and inhibits the recognition of biotin moieties with avidin either below or above its T_（cp）.This demonstrates the significant architecture effects from dendronized polymers on the biotin moieties to shift onto periphery of the collapsed aggregates,which should be a prerequisite for protein *** kinds of novel thermoresponsive copolymers may pave a way for the interesting biological applications in areas such as reversible activity control of enzyme or proteins,and for controlled delivery of drugs or genes.

关键词： Dendronized copolymers Dendrimers Thermoresponsive polymers Protein recognition Biotin-avidin interaction Supramolecular chemistry

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High-performance porous carbon foams via catalytic pyrolysis of modified isocyanate-based polyimide foams for electromagnetic shielding

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Nano Research 2022年第8期15卷 6851-6859页

作者： Zhouping Sun Bin Shen Yang Li Jiali Chen Wenge Zheng Ningbo Key lab of polymer Materials Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China College of Chemistry and Pharmaceutical Engineering Huanghuai UniversityZhumadian 463000China

Porous carbon skeletons(PCSs)derived from isocyanate-based aromatic polyimide foams(PIFs)by high-temperature pyrolysis are very promising in the fabrication of high-performance polymer composite foams for electromagnetic interference(EMI)shielding due to their efficient conductive networks and facile preparation ***,severe volumetric shrinkage and low graphitization degree is not conducive to enhancing the shielding efficiency of the ***,ferric acetylacetonate and carbon-nanotube coating have been introduced in isocyanate-based PIFs to greatly suppress the serious shrinkage during pyrolysis and improve the graphitization degree of the final carbon foams through the Fe-catalytic graphitization process,thereby endowing them with better EMI-shielding performance even at lower pyrolysis temperature compared to the control ***,compressible polydimethylsiloxane(PDMS)composite foams with the as-prepared carbon foams as prefabricated PCSs have also been fabricated,which could provide not only stable shielding effectiveness(SE)performance even after a thousand compressions,but also multiple functions of Joule heating,thermal insulation and infrared *** study offers a feasible route to prepare high-performance PCSs in a more energy-efficient manner via PIF pyrolysis,which is very promising in the manufacture of multifunctional conductive polymer composite foams.

关键词： porous carbon skeletons isocyanate-based polyimide foams catalytic graphitization electromagnetic interference shielding multiple functions

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SYNTHESIS OF BIMODAL POLYETHYLENE WITH UNSYMMETRICAL α-DIIMINE NICKEL COMPLEXES: INFLUENCE OF LIGAND BACKBONE AND UNSYM-SUBSTITUTED ANILINE MOIETY

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Chinese Journal of polymer Science 2013年第4期31卷 563-573页

作者： Hai-yang Gao Feng-shou Liu Hai-bin Hu Fang-ming Zhu 伍青 DSAPM lab PCFM LabInstitute of Polymer ScienceSchool of Chemistry and Chemical EngineeringSun Yat-Sen University

A series of unsymmetrical a-diimine nickel complexes with various backbones and substituted aniline moieties were synthesized and characterized. The crystallographic analysis of the nickel complexes confirmed the existence of meso-and rac-configuration in solid structure. Nickel complexes after activation by MAO were screened for ethylene polymerization to evaluate backbone substituent effect on synthesis of bimodal PE. Acenaphthyl nickel complex with planar backbone afforded a bimodal PE with a broad polydispersity, whereas camphyl nickel complex with rigid and bulky backbone afforded a monomodal PE with a narrow polydispersity. Steric effect of aniline moiety for acenaphthyl nickel complex was also examined, and bimodal PE with dominant high-molecular-weight fraction was obtained by modifying substituents on aniline moiety.

关键词： a-Diimine nickel Stereo-isomer Polyethylene Bimodal molecular weight distribution.

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A STUDY ON MECHANICAL PROPERTIES OF γ-RAY IRRADIATED HDPE FILLED WITH SERICITE-TRIDYMITE-CRISTOBALITE

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Chinese Journal of polymer Science 1998年第4期16卷 339-344页

作者：徐闻肖望东徐僖 The State Key lab. of polymer Materials Engineering Polymer Research Institute of Chengdu University of Science and Technology Chengdu 610065 China

The effect of γ-ray irradiation on the mechanical properties of high densitypolyethylene(HDPE) filled with sericite-tridymite-cristobalite(STC) was studied. The ex-perimental results show that γ-ray irradiation can improve the affinity between HDPE andSTC, and the dispersion of STC in HDPE matrix. Compared with HDPE/STC (80/20)blend, the yield stress and impact strength of irradiated HDPE (10kGy)/STC (80/20) blendare increased from 22.8 MPa and 70J/m to 28.5 MPa and 144J/m. The yield stress andimpact strength of HDPE/irradiated HDPE/STC (48/32/20) are 27.8MPa and 210J/m,respectively.

关键词： γ-Ray irradiation High density polyethylene Sericite-tridymite-cristobalite

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BIODEGRADABLE ALIPHATIC/AROMATIC COPOLYESTERS BASED ON TEREPHTHALIC ACID AND POLY(L-LACTIC ACID):SYNTHESIS,CHARACTERIZATION AND HYDROLYTIC DEGRADATION

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Chinese Journal of polymer Science 2010年第3期28卷 405-415页

作者：方征平 Institute of polymer Composites Zhejiang UniversityKey Laboratory of Macromolecular Synthesis and Functionalization Ministry of Education lab of polymer Materials and Engineering Ningbo Institute of TechnologyZhejiang University

Biodegradable aliphatic/aromatic copolyesters, poly（butylene terephthalate-co-lactate）（PBTL） were prepared via direct melt polycondensation of terephthalic acid （TPA）, 1,4-butanediol （BDO） and poly（L-lactic acid） oligomer （OLLA）. The effects of polymerization time and temperature, as well as aliphatic/aromatic moiety ratio on the physical and thermal properties were investigated. The largest molecular weight of the copolyesters was up to 64100 with molecular weight distribution index of 2.09 when the polycondensation was carried out at 230℃ for 6 h. DSC, XRD, DMA and TGA analysis clearly indicated that the degree of crystallinity, glass-transition temperature, melting point, decomposition temperature, tensile strength, elongation and Young＇s modulus were influenced by the ratio between TPA and OLLA in the final copolyesters. Hydrolytic degradation results demonstrated that the incorporation of biodegradable lactate moieties into the aromatic polyester could efficiently improve hydrolytic degradability of the copolymer even though it still had many aromatic units in the main chains.

关键词： Aliphatic/aromatic copolyesters Direct melt polycondensation Biodegradable

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