共查询到20条相似文献,搜索用时 31 毫秒
1.
Ying‐Ling Liu Chia‐Yun Hsieh 《Journal of polymer science. Part A, Polymer chemistry》2006,44(2):905-913
Crosslinked polymeric materials, which exhibit thermal remendability and removability through Diels–Alder (DA) and retro‐DA reactions, were obtained from using multifunctional maleimide and furan compounds as monomers. The synthesized monomers possess low melting points and good solubility in organo solvents to show excellent processing properties. The performance of DA and retro‐DA reactions were demonstrated with DSC and FTIR measurements. High performance of thermal remendablility and removability of the crosslinked materials were observed with SEM and solvent tests. These materials were applicable in advanced encapsulants and structural materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 905–913, 2006 相似文献
2.
Gang He Valeriy V. Ginzburg Anna C. Balazs 《Journal of Polymer Science.Polymer Physics》2006,44(17):2389-2403
Nanoparticle additives provide a means of imparting the desired electrical, optical, or mechanical properties to a polymeric matrix. The difficulty faced in creating these composites is determining the optimal conditions for forming a thermodynamically stable mixture, where the particles will not phase separate from the matrix material. This challenge is even more daunting when the polymeric matrix is itself a multicomponent mixture, as is often the case in advanced materials. Ideally, the nanoparticles would not only contribute the needed physical properties, but also stabilize the mixture so that the entire system forms a single‐phase system. In this study, we use a free energy expression for a binary blend that contains nanoparticles and take the interaction parameters between the different species to be independent variables. Thus, the particles can have distinct enthalpic interactions with each of the polymeric components. Using this expression, we determine the conditions under which the mixture forms a stable, single‐phase material. In particular, we isolate how variations in the system's parameters (e.g., polymer composition, particle volume fraction, particle size, interaction energies) affect the phase diagrams. The findings provide guidelines for creating effective formulations and can allow researchers to understand how choices made in the nature of the components affect the overall macroscopic properties. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2389–2403, 2006 相似文献
3.
Yuan Fang Li Chen Su Chen 《Journal of polymer science. Part A, Polymer chemistry》2009,47(4):1136-1147
We report on a new strategy for fabricating well‐defined POSS‐based polymeric materials with and without solvent by frontal polymerization (FP) at ambient pressure. First, we functionalize polyhedral oligomeric silsesquioxane (POSS) with isophorone diisocyanate (IPDI). With these functionalized POSS‐containing isocyanate groups, POSS can be easily incorporated into a poly(N‐methylolacrylamide) (PNMA) matrix via FP in situ. Constant velocity FP is observed without significant bulk polymerization. The morphology and thermal properties of POSS‐based hybrid polymers prepared via FP are comparatively investigated on the basis of scanning electronic microscopy (SEM) and thermogravimetric analysis (TGA). Results show that the as‐prepared POSS‐based polymeric materials exhibit a higher glass transition temperature than that of pure PNMA, ascribing to modified POSS well‐dispersed in these hybrid polymers. Also, the products with different microstructures display different thermal properties. The pure PNMA exhibits a featureless morphology, whereas a hierarchical morphology is obtained for the POSS‐based polymeric materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1136–1147, 2009 相似文献
4.
Céline Calvino Laura Neumann Christoph Weder Stephen Schrettl 《Journal of polymer science. Part A, Polymer chemistry》2017,55(4):640-652
Mechanochromic materials respond to mechanical stimuli with a change of their optical properties. Such materials are of interest for many technological applications and support fundamental research as they help improving the understanding of stress transfer in polymeric objects and aid in the identification of the processes that lead to mechanical failure. In this highlight, different approaches are discussed that permit the design of polymeric materials, which signal mechanical stresses through a chromic response. This highlight emphasizes materials that exhibit mechanically induced changes of their intrinsic absorption or emission properties. These responses almost exclusively originate from changes of molecular structure, conformational rearrangements, or disruption of intermolecular interactions. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 640–652 相似文献
5.
Environmentally benign atom transfer radical polymerization: Towards “green” processes and materials
Nicolay V. Tsarevsky Krzysztof Matyjaszewski 《Journal of polymer science. Part A, Polymer chemistry》2006,44(17):5098-5112
Atom transfer radical polymerization (ATRP) is a metal complex-catalyzed method of controlled radical polymerization that has been successfully employed to prepare a multitude of well-defined functional polymeric materials. The environmental aspects of ATRP that are reviewed in this work include (i) methods for catalyst removal and its potential further recycling, (ii) development of active ATRP catalysts that can be used at low concentration, (iii) conducting ATRP in environmentally friendly media (water, supercritical carbon dioxide, and ionic liquids), and (iv) application of ATRP to the production of advanced materials such as self-plasticized poly(vinyl chloride) and (bio)degradable polymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5098–5112, 2006 相似文献
6.
Ravin Narain Abdelghani Housni Lynsay Lane 《Journal of polymer science. Part A, Polymer chemistry》2006,44(22):6558-6568
We report here the successful functionalization of single‐walled carbon nanotubes with bioinspired sugar and phosphocholine polymeric structures via surface‐initiated atom transfer radical polymerization. The surface‐polymer‐coated carbon nanotubes have been systematically analyzed by Raman, infrared, ultraviolet–visible, and nuclear magnetic resonance spectroscopy and high‐resolution transmission electron microscopy, which give strong evidence of successful functionalization. The successful aqueous dispersion of the functionalized carbon nanotubes also indicates that functionalization has been achieved. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6558–6568, 2006 相似文献
7.
Liyun Yu Anne Ladegaard Skov Hussein M. Etmimi Peter E. Mallon Alex Adronov Michael A. Brook 《Journal of polymer science. Part A, Polymer chemistry》2016,54(15):2379-2385
While graphene or graphene oxide can make significant improvements in the properties of a wide variety of polymeric materials, their incorporation can be challenged by incompatibility with the polymeric matrix. The modification of graphene oxide with silicones or silanes using the Piers‐Rubinsztajn reaction improves dispersibility in nonpolar materials, including organic solvents and silicone pre‐elastomers. A high loading (up to 10 wt %) of modified graphene oxide in silicone elastomers could be achieved, which resulted in enhanced mechanical performance and reduced gas permeability. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2379–2385 相似文献
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Shiro Kobayashi Hiroshi Uyama 《Journal of polymer science. Part A, Polymer chemistry》2002,40(2):192-209
Topics concerning the cationic ring‐opening polymerization of cyclic imino ethers and functional material production based on the resulting polymers are reviewed. Cyclic imino ethers are readily subjected to isomerization polymerization via cationic initiators. Mechanistic studies have provided a new concept, electrophilic polymerization. Double isomerization polymerization and no‐catalyst alternating copolymerization are interesting examples that show characteristics of the ring opening of cyclic imino ethers. The living polymerization of these monomers affords precisely controlled polymeric materials. Through the use of the unique properties of the product polymers, various functional polymeric materials, such as polymeric nonionic surfactants, compatibilizers, hydrogels, stabilizers for dispersion polymerization, biocatalyst modifiers, and supramolecular assemblies, have been developed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 192–209, 2002 相似文献
10.
Alexander Alexeev Rolf Verberg Anna C. Balazs 《Journal of polymer science. Part A, Polymer chemistry》2006,44(18):2667-2678
We discuss a novel method for capturing the dynamic coupling between a fluid and an elastic solid, the so-called fluid–structure interaction. This method integrates a lattice Boltzmann model to capture the fluid dynamics with a lattice spring model to capture the micromechanics of the solid phase. We then examine the fluid-driven motion of microcapsules, which are modeled as fluid-filled, elastic shells, along a corrugated substrate. We show that the ability of the capsules to navigate along the surface depends critically on capsule's elastic modulus. In particular, we illustrate how this substrate can be utilized to design a device for sorting microcapsules by their mechanical properties. These results apply not only to polymeric microcapsules, but also describe the interaction between the substrate and certain biological cells (e.g., leukocytes and other cells with cytoskeletons). Hence, by isolating species of a certain stiffness, the device could be highly useful for applications in biotechnology and tissue engineering or in the quality control of fabricated microcapsules. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2667–2678, 2006 相似文献
11.
Timothy J. White 《Journal of Polymer Science.Polymer Physics》2012,50(13):877-880
Light can wirelessly direct functional responses in photoresponsive polymeric materials and composites. The intensity, phase, and polarization of light can be spatially modulated into complex patterns with holography (intensity or polarization) or masking (intensity or phase). Deriving from these foundational properties of light, photoresponsive macromolecular systems exhibit exceeding potential to yield rapid and highly engineered macroscopic as well as spatially selectable mechanically adaptive responses useful as soft actuators or topographical surfaces in aerospace, automotive, and biomedical applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献
12.
Andrew P. Abbott Nick Brooks Wayne Eltringham A. Robert Hillman Eric G. Hope 《Journal of Polymer Science.Polymer Physics》2006,44(7):1072-1083
The infusion of difluoromethane (HFC 32) and CO2 into polystyrene and polyethylene has been characterized using a quartz crystal microbalance technique over a range of temperatures and pressures. The results were adequately modeled by Flory‐Huggins theory. Significant plasticization was observed in the polymeric materials and it is shown that manipulation of the experimental temperature, pressure, and rate of depressurisation can cause significant changes in the morphology of the samples. It is demonstrated for the first time how rate constant data for the kinetics of gas sorption can be extracted quickly and easily from in situ quartz crystal microbalance measurements. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1072–1083, 2006 相似文献
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Ji Won Hwang Kyung Nam Kim Joon Hyun Nam Hyun Wook Jung Jung Kwon Oh 《Journal of polymer science. Part A, Polymer chemistry》2014,52(21):3060-3068
Photo‐induced thiol‐ene crosslinked polymeric networks have been extensively explored in constructing a variety of new materials with enhanced mechanical properties for optical, biomedical, and sensing applications. Toward the broad applications, however, tunable mechanical properties are greatly desired. Here, an effective approach utilizing high‐molecular‐weight methacrylate copolymers having pendant thiol and vinyl groups (MCPsh and MCPenes) to modulate thermal and mechanical properties of photo‐induced thiol‐ene crosslinked materials is reported. The MCP copolymers are synthesized by an industrially friendly polymerization method, followed by post‐modification including either a facile coupling reaction or reductive cleavage. Upon UV irradiation, thiol‐ene reactive blends of MCPsh and MCPenes yield highly crosslinked materials through the formation of flexible sulfide linkages. These polysulfide‐crosslinked materials based on rigid MCP backbones exhibit enhanced mechanical properties. Further, their thermal and mechanical properties are tuned by modulating monomer compositions of MCPs as well as varying numbers of pendant SH or vinyl groups (i.e., extent of crosslinking densities). This approach is versatile and effective for development of high performance polymeric materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3060–3068 相似文献
15.
Ton Loontjens 《Journal of polymer science. Part A, Polymer chemistry》2003,41(21):3198-3205
New enabling chemistries have been developed to produce novel well‐defined polymeric materials through the additions of small amounts of reactive functional compounds to standard polymers during regular processing steps. We found that carbonyl biscaprolactam and its derivatives couple polymer chains in a strictly linear fashion. The requirements for fast and well‐controlled coupling reactions, a prerequisite to apply this modular concept, were met. The breakthrough to produce a wide variety of novel polymers came when we found that many building blocks, provided with functional groups and blocked isocyanate groups, could be made on the basis of this chemistry. Blocked isocyanate groups are very suitable coupling units to fix desired functions onto polymer backbones. In one example, antifouling coatings were prepared by introducing fluorine groups. In another case, blocked isocyanate functional acrylates were built into a polyacrylate to make self‐crosslinkable coatings. In another illustration, the concept was demonstrated by a novel route to prepare polyrotaxanes from rotaxane monomers provided with blocked isocyanates as polymerizable stopper groups. These reactive functional compounds gave, in a controlled manner, polymeric materials with substantially improved properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3198–3205, 2003 相似文献
16.
Ying‐Ling Liu Gung‐Pei Chang 《Journal of polymer science. Part A, Polymer chemistry》2006,44(6):1869-1876
Epoxy/polyhedral oligometric silsesquioxane (POSS) hybrid materials, containing 50 wt % POSS and exhibiting good homogeneity, were obtained in a two‐step preparation. Monoamine‐functionalized POSS was first reacted with diglycidyl ether of bisphenol A to form an epoxy POSS precursor, which was then cured. Curing agents such as 4,4′‐diaminodiphenylmethane, dicyandiamide (DICY), and diethylphosphite (DEP) were used for the synthesis of the epoxy–POSS hybrid materials. The use of small‐molecule curing agents, such as DICY and DEP, efficiently avoided macrophase separations and enhanced the thermal properties of the hybrid materials. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1869–1876, 2006 相似文献
17.
Matthew Laskoski Dawn D. Dominguez Teddy M. Keller 《Journal of polymer science. Part A, Polymer chemistry》2006,44(15):4559-4565
New multiple aromatic ether containing oligomeric cyanate ester resins have been synthesized using a modified Ullmann reaction. The oligomeric monomers were prepared by reacting resorcinol and 1,3‐ or 1,4‐dibromobenzene in the presence of potassium carbonate and a catalytic amount of a copper(I) complex in a N,N‐dimethylformamide/toluene mixture. The hydroxyl terminated intermediates were end‐capped with the cyanate moiety by reaction with cyanogen bromide in the presence of triethylamine in dry acetone. The oligomeric cyanate ester monomers are liquid at room temperature, which enhance their processability to polymeric networks. The thermo‐oxidative properties were determined for the new cyanate ester polymers as well as their storage modulus. The length of the aromatic ether spacer between the terminal cyanate ester groups was varied to investigate the effect of changing the spacer length on the properties of the material. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4559–4565, 2006 相似文献
18.
New soybean oil‐styrene‐divinylbenzene thermosetting copolymers. III. Tensile stress–strain behavior
The tensile stress–strain behavior and fracture properties of some new soybean oil based polymeric materials were investigated at room temperature. These materials were prepared by the cationic copolymerization of regular soybean oil, low saturation soybean oil (LoSatSoy oil), or conjugated LoSatSoy oil with styrene and the diene comonomers divinylbenzene, norbornadiene, or dicyclopentadiene in a process initiated by boron trifluoride diethyl etherate (BF3 · OEt2) or related modified initiators. These new polymeric materials exhibited tensile stress–strain behavior ranging from soft rubbers through ductile to relatively brittle plastics. The Young's moduli of these polymers varied from 3 to 615 MPa, the ultimate tensile strengths varied from 0.3 to 21 MPa, and the elongation at break varied from 1.6 to 300%. These properties are obviously related to their crosslink densities. The conjugated LoSatSoy oil polymers had higher mechanical properties than the corresponding LoSatSoy oil and regular soybean oil polymers with the same stoichiometry. Some conjugated LoSatSoy oil polymers with appropriate stoichiometries showed yielding behavior in the tensile test process. A variety of new polymer materials can thus be prepared by varying the stoichiometry, the type of soybean oil, and the crosslinking agent. These soybean oil based polymers possessed mechanical properties comparable to those of commercially available rubbery materials and conventional plastics and thus may serve as replacements in many applications. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 60–77, 2001 相似文献
19.
Ian Manners 《Journal of polymer science. Part A, Polymer chemistry》2002,40(2):179-191
Inorganic polymers are relatively unexplored because the efficient formation of macromolecular chains from atoms of transition metals and main group elements has presented a synthetic challenge. Nevertheless, these materials offer exciting opportunities for accessing properties that are significantly different from and which therefore complement those available with the well‐established organic systems. Inorganic block copolymers are of particular interest for the generation of functional, nanoscale supramolecular architectures and hierarchical assemblies using self‐assembly processes. This article focuses on research in my group over the past decade, which has targeted the development of new and controlled routes to inorganic polymers and their subsequent use in forming supramolecular materials as well as studies of their properties and applications. The use of ring‐opening polymerization (ROP) and transition‐metal‐catalyzed polycondensation approaches are illustrated. Controlled ROP procedures have been developed that allow access to polyferrocene block copolymers that self‐assemble into interesting nanoscopic architectures such as cylinders and superstructures such as flowers. The future prospects for inorganic polymer science are discussed, and a growing emphasis on the study of supramolecular inorganic polymeric materials is predicted. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 179–191, 2002 相似文献
20.
《Journal of Polymer Science.Polymer Physics》2018,56(5):414-428
Nanoindentation is a widely used technique to characterize the mechanical properties of polymeric materials at the nanoscale. Extreme surface stiffening has been reported for soft polymers such as poly(dimethylsiloxane) (PDMS) rubber. Our recent work [J. Polym. Sci. Part B Polym. Phys. 2017 , 55, 30–38] provided a quantitative model which demonstrates such extreme stiffening can be associated with experimental artifacts, for example, error in surface detection. In this work, we have further investigated the effect of surface detection error on the determination of mechanical properties by varying the sample modulus, instrument surface detection criterion, and probe geometry. We have examined materials having Young's moduli from ∼2 MPa (PDMS) to 3 GPa (polystyrene) using two different nanoindentation instruments (G200 and TI 950) which implement different surface detection methods. The results show that surface detection error can lead to apparent large stiffening. The errors are lower for the stiffer materials, but can still be significant if care is not taken to establish the range of the surface detection error in a particular experimental situation. We have also examined the effect of pressure beneath the probe on the nanoindentation‐determined modulus of polystyrene with different probe geometries. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 414–428 相似文献