CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 11
·1564-1574
·
IF 1.42
Li Ming,Zhang Li-fen,Tao Mei-xia,Cheng Zhen-ping,Zhu Xiu-lin
In this work, a fluorescent monomer 2-(9-carbazolyl) ethyl vinyl ether (CEVE) was synthesized in our lab, and its photo-induced living cationic copolymerization behavior with isobutyl vinyl ether (IBVE) was investigated in detail using diphenyliodonium chloride (DPICl)/2,2-dimethoxy-2-phenylacetophenone (DMPA) and zinc bromide (ZnBr 2 ) initiating system in dichloromethane solution at 5 °C, −5 °C, and −15 °C, respectively. The living nature of this copolymerization system was confirmed by adding fresh comonomer method after the copolymerization almost finished. In addition, the obtained fluorescent copolymer poly(IBVE- co -CEVE) has a low glass transition temperature ( T
g ), below −10 °C.
研究领域:
高分子化学
·
功能高分子
·
光响应材料
·
聚合反应机理
·
荧光材料
✓ 已验证
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 10
·2284
·
IF 3.426
Rui Huang,Jinshui Yao,Qiuhong Mu,Dan Peng,Hui Zhao,Zhizhou Yang
Silicone resin is a high-temperature resistant material with excellent performance. The improvement of its thermal stability has always been the pursuit of researchers. In this paper, a sequence of silicone resins containing trifluorovinyl ether groups were prepared by the co-hydrolysis-polycondensation of methyl alkoxysilane monomers and {4-[trifluorovinyl(oxygen)]phenyl}methyldiethoxysilane. The structures of the silicone resins were characterized by FT-IR and1H NMR. The curing process of them was studied by DSC and FT-IR spectra, and results showed that the curing of the resins included the condensation of the Si-OH groups and the [2 + 2] cyclodimerization reaction of the TFVE groups, which converted to perfluorocyclobutane structure after curing. The thermal stability and thermal degradation behavior of them was studied by TGA and FT-IR spectra. Compared with the pure methyl silicone resin, silicone resins containing TFVE groups showed better thermal stability under both N2and air atmosphere. Their hydrophobic properties were characterized by contact angle test. Results showed that PFCB structure also improved the hydrophobicity of the silicone resin.Keywords:silicone resin;trifluorovinyl ether group;thermal stability;degradation
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Qingyu Liao,Dong Chen,Xianhong Zhang,Yuhong Ma,Changwen Zhao,Wantai Yang
A facile synthetic route was developed to prepare a surface-grafted brush layer of poly(vinyl ethers) (PVEs) directly by a radical mechanism, with the “naked” Li+ acting as a catalyst. Density functional theory calculations suggested that complexation of naked Li+ to VEs significantly reduced the highest unoccupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap from 5.08 to 0.68 eV, providing a better prospect for electron transfer. The structure, morphology, and surface properties of grafted polymer layers were characterized using attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and dynamic water contact angle (DCA). Moreover, ellipsometry data indicated that the thickness of the polymer brushes was in the range of 20–60 nm, which corresponds to the grafting densities of 0.65–1.15 chain/nm2, and DCA decreased from 84.4 to 45.3°. Most importantly, no hydrolysis was observed for the modified surface after 30 days of exposure to phosphate-buffered saline solution, 0.1 mol/L NaOH(eq) and 0.1 mol/L HCl(eq), demonstrating excellent hydrolysis resistance with long service life. In addition, as a proof of concept, the side hydroxyl groups of grafted PVEs provide active sites for efficient fixation of bioactive molecules, e.g., glycosaminoglycan and serum protein.
研究领域:
高分子化学
·
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 31
·
IF 1.768
Yan Yang,Funian Mo,Yangyang Chen,Yingyi Liu,Shaojun Chen,Jiandong Zuo
Researchers are actively developing shape memory polymers (SMPs) for smart biomaterials. This paper reports a new SMP system synthesized from biocompatible 2-(dimethylamino) ethyl methacrylate (DMAEMA), butyl acrylate (BA) and tri(ethylene glycol) divinyl ether (TDE). Preliminary results show that the DMAEMA-co-BA-co-TDE copolymers form micelles in aqueous solution due to chemical crosslinking and hydrophobicity. The micelle size decreased with the increase in the BA content since the hydrophobicity of copolymers increases with the increase of BA content. The resulting polymer films contain–N(CH 3 ) 2 functional groups for further biomaterial applications. The thermal stability of DMAEMA-co-BA-co-TDE copolymers is determined by the DMAEMA structure and content. Moreover, the copolymers form micro-phase-separated structures containing a reversible amorphous soft phase, and the storage moduli decreases significantly around T g . Therefore, good thermal-induced shape memory effects are achieved in the DMAEMA-co-BA-co-TDE copolymers by adjusting the BA content. This work proposes a new strategy for designing smart biomaterials using a biocompatible monomer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42312.
研究领域:
高分子化学
·
生物医学材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2022
·Vol. 62
·期 9
·2769-2778
·
IF 2.573
Xiaodong Chen,Xinde Tang,Cuizhen Zhang,Xiao Lu,Haichao Guo,Xuefan Li,Laixue Pang,Yong Yang,Fuying Dong
Polycarboxylate ether superplasticizers (PCEs) with comb-shaped molecular structures have attracted considerable attention in the area of admixtures for construction engineering. However, there are some contradictions in studying the relationship between the molecular structure and property of PCE due to its random structure based on traditional free radical polymerization, which is confused for designing and developing novel PCEs. In this article, a series of reversible addition fragmentation chain transfer (RAFT) polymerization-based polycarboxylate ether superplasticizers (RPCs) were prepared by the copolymerization of acrylic acid (AA) and ethylene-glycol monovinyl polyethylene glycol (EPEG). The chemical structure and composition of RPCs were characterized and their adsorption behavior and dispersion properties were conducted. The results demonstrate that the molecular weights of RPCs do not vary significantly with prolonging reaction time, and the actual monomer ratio in RPCs displays a significant change to the feed one due to the monomer reactivity and conversion at higher reaction temperature, which is different from conventional free radical polymerization. The dispersion and adsorption properties of RPCs to cement were evaluated by slurry fluidity tests and total organic carbon (TOC) experiments. The effect of polymerization temperature and time on the dispersion ability has been systematically studied. The results indicate that the dispersion ability and adsorption capacity of RPCs are closely related to their molecular structures. The dispersion ability of RPCs were enhanced with increasing carboxyl group density in a certain range of monomer molar ratios (≤6:1). This study will provide a new platform for designing and developing high-performance and rational cost-effective superplasticizers with well-defined structure and controlled molecular weight.
研究领域:
材料科学
·
化学工程
·
建筑材料
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Qiong Li,Songqi Ma,Pengyun Li,Binbo Wang,Zhen Yu,Hongzhi Feng,Yanlin Liu,Jin Zhu
Covalent adaptable networks (CANs) represent a transition material combining favorable features of thermosets and thermoplastics. However, it is still a huge challenge to simultaneously achieve fast reprocessability and high performance for CANs. Here, we designed catechol-based acetal CANs to achieve continuous reprocessing without sacrificing thermal and mechanical properties. A small-molecule model study demonstrated the significantly accelerated acetal exchange by neighboring group participation (NGP) of phenolic hydroxyl. Using this internally catalyzed acetal chemistry, a series of CANs with a broad range of properties were simply prepared from bio-based epigallocatechin gallate (EGCG) and tri(ethylene glycol) divinyl ether (TEGVE) via one-step “click” cross-linking without using catalysts or releasing small-molecule byproducts. The dynamic nature of the CANs was confirmed via stress relaxation and multiple recycling methods including extrusion. While the dense cross-link density and high rigidity of the network provided high solvent resistance and mechanical properties. This work provides a promising and practical method to produce fast-reprocessing dynamic covalent polymer networks with dense cross-link density and superior performance.
研究领域:
材料科学
·
聚合物化学
·
可持续材料
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 21
·26276-26304
·
IF 3.056
Xiao Dingtian,Qing Shan,Chen Pengfei,Yu Zhifeng,Xiao Huaqiang,Wang XiaoDing
In this study, a diversified waste recycling system and a green processing technology are proposed. This research not only finds feasible solutions to alleviate environmental problems of plastic pollution and straw burning but also provides new reuse methods for oyster shell waste and hogwash oil. The developed noval biocomposite material is conducive to the green development of express industry. This paper evaluates the performance of materials from many aspects: X-ray computed tomography characterization, fundamental physical properties, mechanical properties, microscopic morphology, SEM morphology, and comprehensive performance of products. Two kinds of products with economic value are found. One is sample 4, which is suitable for making granular products due to its low cost (0.328$/500 g). Another is sample 13, which is suitable for manufacturing green packaging materials due to its excellent mechanical properties (tensile strength 14.15 MPa; elongation at break 12.68%; Young’s modulus 8189.89 MPa). Based on the experimental results, the process of the composite is simulated to study the different strengthening mechanisms of arabic gum and poly(methyl vinyl ether-alt-maleic anhydride). Arabic gum uses chemical reaction and principle of similarity and intermiscibility to fuse with biomass to form homogeneous hybrid in the form of liquid gel. Poly(methyl vinyl ether-alt-maleic anhydride) indirectly adheres filler to the matrix through ring-opening reaction and structural similarity. The new emulsification system caused by arabic gum promotes the arabic gum and nano-fluid coupling cross-linking system to produce a decentralized cross-linked network and inhibit the pernicious molecular chain entanglement.
研究领域:
材料科学
·
环境工程
·
可持续发展
·
复合材料
·
废物管理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2024
·
IF 3.9
Jingwen Yao,Jiaying Tong,Dan Zhao,Dong Chen,Yuhong Ma,Wantai Yang
The reversible addition-fragment chain transfer (RAFT) alternating copolymerization of 2-hydroxyethyl vinyl ether (HEVE) and dimethyl maleate (DMM) is achieved with S -(cyanomethyl) O -ethyl carbonodithioate (CMX) as medaitor and 2,2′-azobis(2-methylpropionitrile) (AIBN) as radical initiator. The effects of monomer concentrations, comonomer feeding ratios, molar ratio of monomer to CMX and solvent on the copolymerization and copolymer structure are systematically investigated. The living feature of the HEVE and DMM copolymerization is demonstrated by the linear increasement of the molecular weights with the monomer conversions, and relatively narrow molecular weight distributions of the copolymers. With dimethyl carbonate as solvent, poly(HEVE- alt -DMM) with M n = 5200 and M w / M n = 1.34 are synthesized at [HEVE]/[DMM]/[CMX]/[AIBN] = 100/100/3/1. The alternating structure of the copolymer is demonstrated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and proton nuclear magnetic resonance spectroscopy ( 1 H NMR). The both α, ω-end groups are mainly originated from the moiety of CMX. To further demonstrate the living feature of the alternating copolymerization, chain extension and block copolymerization are also carried out. With poly(HEVE- alt -DMM) as macro-CTA ( M n = 5200, M w / M n = 1.34), the chain-extension reaction has been successfully realized ( M n = 9600, M w / M n = 1.70), and the block copolymer with vinyl neonanoate as monomer also successfully synthesized ( M n = 9800, M w / M n = 1.42). Graphical
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）