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81.
Muquan Yang Jun Mao Wei Nie Zhixin Dong Dapeng Wang Ziliang Zhao Xiangling Ji 《Journal of polymer science. Part A, Polymer chemistry》2012,50(10):2075-2083
We present herein a mild and rapid method to create diblock copolymer brushes on a silicon surface via photoinitiated “thiol‐ene” click reaction. The silicon surface was modified with 3‐mercaptopropyltrimethoxysilane (MPTMS) self‐assembled monolayer. Then, a mixture of divinyl‐terminated polydimethylsiloxane (PDMS) and photoinitiator was spin‐coated on the MPTMS surface and exposed to UV‐light. Thereafter, a mixture of thiol‐terminated polyethylene glycol (PEG) and photoinitiator were spin‐coated on the vinyl‐terminated PDMS‐treated surface, and the sequent photopolymerization was carried out under UV‐irradiation. The MPTMS, PDMS, and PEG layers were carefully identified by X‐ray photoelectron spectroscopy, atomic force microscopy, ellipsometry, and water contact angle measurements. The thickness of the polydimethylsiloxane‐block‐poly(ethylene glycol) (PDMS‐b‐PEG) diblock copolymer brush could be controlled by the irradiation time. The responsive behavior of diblock copolymer brushes treated in different solvents was also discussed. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
82.
Miao Hong San‐Rong Liu Bai‐Xiang Li Yue‐Sheng Li 《Journal of polymer science. Part A, Polymer chemistry》2012,50(12):2499-2506
A series of functional polyethylenes have been simply and efficiently synthesized via the combination of regioselective ethylene/5‐vinyl‐2‐norbornene (VNB) copolymerization using [PhNC(CF3)CHCO(Ph)]2TiCl2 catalyst and following ultraviolet light initiated thiol‐ene click reaction. On treatment of ethylene/VNB copolymer with different thiols including mercaptoethanol, 1‐thioglycerol, methyl mercaptoacetate, methyl mercaptopropionate, 2‐mercaptoethylamine, mercaptoacetic acid, and mercaptopropanoic acid, various polar groups have been successfully introduced into the polyethylene. Except 2‐mercaptoethylamine, the functionalizations are quite efficient with the degree of functionalization higher than 94%, which is independent of thiol structure and double bond content. The content of polar group in functional polyethylene can be tuned in a wide range of 0–30 mol %. Gel permeation chromatography profiles indicate all functional polyethylenes that have very high molecular weights (160–336 kg/mol) with homogeneous formation. Besides, systematic investigation of the influence of vinyl type and thiol structure on reactivity has been also carried out. By treatment of mercaptoethanol with different copolymers (ethylene/VNB, ethylene/5‐ethylidene‐2‐norbornene, and ethylene/dicyclopentadiene copolymer), the order of vinyl reactivity can be summarized as terminal > internal > cyclic double bond. For different thiols, the reactivity has the sequence of SHCH2COOH > SHCH2COOCH3 > SHCH2CH2COOH > SHCH2CH2COOCH3 > SHCH2CH(OH)CH2OH > SHCH2CH2OH > SHCH2CH2NH2, which is depended on the solubility and the electron‐withdrawing inductive effect of polar group. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
83.
Dnyaneshwar V. Palaskar Aurélie Boyer Eric Cloutet Jean‐François Le Meins Benoit Gadenne Carine Alfos Céline Farcet Henri Cramail 《Journal of polymer science. Part A, Polymer chemistry》2012,50(9):1766-1782
A series of novel fatty acid‐based diols were designed and synthesized from sunflower and ricin oils using optimized chemical reactions and purifications. These diols were categorized in two different types: (i) fatty acid‐based monoester containing diols (FAmE‐1 to FAmE‐6) and (ii) fatty acid‐based diester containing diols (FAdE‐1 to FAdE‐8). Their synthesis involved a series of reactions such as transesterification, epoxidation, ring opening of epoxide, and thiol‐ene additions. Analyses of these new fatty acid‐based diols were performed by HPLC/GC and NMR spectroscopy. The latter were then demonstrated as polyurethane (PU) precursors in the bulk polymerization with isophorone diisocyanate in the presence of dibutyl tin dilaurate as a catalyst. The effects of the diol nature and purity on the PU synthesis and properties were investigated. The structural characterization of the different PUs was carried out by means of FTIR, 1H NMR, and 1H DOSY NMR spectroscopy. The thermomechanical and rheological properties of these new PUs were found dependent on the chemical structure and purity of the diol building block. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
84.
Zhixian Xu Suyun Jie Bo‐Geng Li 《Journal of polymer science. Part A, Polymer chemistry》2014,52(22):3205-3212
Well‐defined diblock copolymers of linear polyethylene (PE) and poly(dimethylsiloxane) (PDMS) have been synthesized through a facile route combining the thiol‐ene click chemistry of vinyl‐terminated polyethylene (PE‐ene) and the sequential esterification reaction. The resulting diblock copolymers are characterized by 1H NMR, FT‐IR, DSC, TGA, and TEM. In addition, the PE‐b‐PDMS diblock copolymers have been evaluated as compatibilizers in the blends of high‐density polyethylene (HDPE) and silicone oil. The morphological analysis and mechanical properties demonstrate that the compatibilized blends with low loading concentration of PE‐b‐PDMS display significant improvements in modulus of elasticity and elongation at break as compared to the uncompatibilized binary blends. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3205–3212 相似文献
85.
86.
Andrew J. Guenthner David M. Hess Jessica J. Cash 《Journal of Polymer Science.Polymer Physics》2010,48(4):396-410
The morphology of sparse filament networks formed during photopolymerization‐induced phase separation of mixtures of NOA81 (a UV‐curable thiol‐ene adhesive) in mixed cosolvents consisting of water, diglyme, and polyethers of varying molecular weight was investigated as a function of the molecular weight and relative amount of the polyethers used. During photopolymerization (50 mW/cm?2 of 365 nm radiation for 60 s) of solutions containing 5 wt % NOA81 and a total oligo‐ether or polyether to water ratio of 8:1 by weight, viscoelastic phase separation produced a sparse network of interconnected NOA81 filaments. During the subsequent evaporation and/or solidification of the solvents, the network compacted significantly via a collapse process that was curtailed by increasing both the weight fraction and molecular weight of the nonvolatile polyether. The influence of mass and momentum transport processes on the collapse of the phase‐separated network and the resultant final morphology was determined with the aid of dimensional analysis, leading to the identification of sedimentation and compaction driven by the motion of the interface as key factors. The networks exhibiting the least collapse combine a high level of interconnectivity and specific surface area with a low occupied volume fraction while being fabricated via a simple, template‐free process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 396–410, 2010 相似文献
87.
Zhiyun Li Pengshan Zhang Wei Lu Lun Peng Yun Zhao Gaojian Chen 《Macromolecular rapid communications》2016,37(18):1513-1519
Effectively detecting pH changes plays a critical role in exploring cellular functions and determining physiological and pathological processes. A novel ratiometric pH probe based on a glycopolymer, armored with properties of serum‐stability, tumor‐targeting, and pH monitoring, is designed. Random copolymers of 2‐(methacrylamido) glucopyranose and fluorescein O‐methacrylate are first synthesized by reversible addition fragmentation chain transfer polymerization. Acryloxyethyl thiocarbamoyl rhodamine B is then attached to the polymer chain to prepare ratiometric fluorescent pH probes via a thiol‐ene reaction. The synthesized polymeric probes are characterized by NMR, gel permeation chromatography, UV–vis spectroscopy, and transmission electron microscopy, and the fluorescence responses are examined in phosphate buffer at different pHs. The cytotoxicity and confocal imaging experiments of the probes are detected using HeLa cells, demonstrating a low toxicity and superior biocompatibility for detecting pH changes in bioapplications.
88.
A combination of a thiol‐Michael addition reaction and a free radical mediated thiol–ene reaction is employed as a facile and efficient approach to carbosiloxane dendrimer synthesis. For the first time, carbosiloxane dendrimers are constructed rapidly by an orthogonal click strategy without protection/deprotection procedures. The chemoselectivity of these two thiol–ene click reactions leads to a design of a new monomer containing both electron‐deficient carbon–carbon double bonds and unconjugated carbon–carbon double bonds. Siloxane bonds are introduced as the linker between these two kinds of carbon–carbon double bonds. Starting from a bifunctional thiol core, the dendrimers are constructed by iterative thiol–ene click reactions under different but both mild reaction conditions. After simple purification steps the fifth dendrimer with 54 peripheral functional groups is obtained with an excellent overall yield in a single day. Furthermore, a strong blue glow is observed when the dendrimer is excited by a UV lamp.
89.
Matthew J. Kade Daniel J. Burke Craig J. Hawker 《Journal of polymer science. Part A, Polymer chemistry》2010,48(4):743-750
As a tribute to Professor Charlie Hoyle, we take the opportunity to review the impact of thiol‐ene chemistry on polymer and materials science over the past 5 years. During this time, a renaissance in thiol‐ene chemistry has occurred with recent progress demonstrating its unique advantages when compared with traditional coupling and functionalization strategies. Additionally, the robust nature of thiol‐ene chemistry allows for the preparation of well‐defined materials with few structural limitations and synthetic requirements. To illustrate these features, the utility of thiol‐ene reactions for network formation, polymer functionalization, dendrimer synthesis, and the decoration of three‐dimensional objects is discussed. Also, the development of the closely related thiol‐yne chemistry is described. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 743–750, 2010 相似文献