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聚合物熔体膜在基体表面上的润湿和铺展行为受铺展系数和Hamaker常数影响。对于不能在基体表面上铺展的聚合物膜,当处于其玻璃化温度以上时,聚合物熔体膜将破裂,出现非连续区域。随着体系处于聚合物玻璃化温度以上时间的延长,非连续部分尺寸不断增长,增长速率与表面张力、聚合物粘度、聚合物液滴在基体表面的平衡接触角等因素有关,平衡后聚合物以液滴的形式在基体表面稳定存在。将带功能端基聚合物加入不能在基体表面上铺展的聚合物中,通过修饰聚合物与基体界面或改变聚合物熔体膜的表面张力,可以使原来不能在基体表面铺展的聚合物保持稳定。本文综述了聚合物熔体膜的铺展和润湿动力学研究进展,并归纳了使聚合物熔体膜稳定的方法。 相似文献
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聚合物接枝纳米颗粒(Polymer grafted nanoparticles,PGNPs)是一类重要的聚合物改性填料。由于表面聚合物链的存在,在一定条件下,PGNPs可以均匀地分散在聚合物基体中,形成"完全相容性"聚合物纳米复合材料。近年来,PGNPs填充聚合物体系的结构-性能关系研究已成为高分子学科的研究热点。本文主要概述了PGNPs的制备及其填充聚合物体系的结构-性能关系。从PGNPs的设计制备、PGNPs在聚合物基体中的分散行为、PGNPs纳米复合体系流变行为和纳米复合材料力学性能4个方面介绍了该领域已经取得的研究进展和现状,并展望该领域今后的发展前景和研究方向。 相似文献
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聚合物基金属复合材料研究进展 总被引:4,自引:0,他引:4
系统评述了聚合物基金属复合材料这一新兴交叉学科的科学范畴、聚合物基体的作用、金属相形态结构、基体与金属两相之间的相互作用。以金属相的形态结构为线索,阐述了该类复合材料在层状复合材料、多层复合材料、纳米复合材料等几个重要方面的形态结构的设计、制备、物性与应用。 相似文献
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具有力刺激响应发光特性的聚合物材料是刺激响应发光材料的重点研究方向,在聚合物力化学、应力检测、聚合物损伤监控、特种包装材料等领域受到了化学家和材料学家的广泛关注。这类材料通常是将具有力刺激响应发光特性的小分子作为发光力敏团,通过化学键合或物理掺杂的方式引入聚合物基体中制备得到。力刺激作用通过聚合物基体传导到发光力敏团,引起发光信号变化,实现力刺激响应发光。本文结合发光力敏团的力刺激响应发光原理和力刺激响应发光聚合物的制备方法,对力刺激响应发光聚合物进行了综述,期望对力刺激响应发光聚合物的研发设计和实际应用提供借鉴。 相似文献
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尼龙6/高岭土界面相互作用对其复合材料力学性能和流变行为的影响 总被引:4,自引:2,他引:4
<正> 无机填料填充复合材料的性能,除了依赖于聚合物基体和填料固有的内在性质外,很大程度上依赖于它们之间的界面性质。因此,研究聚合物/填料界面相互作用,对合理地设计具有优良性能的复合材料具有十分重要的意义。 目前,还很难对粉末填料与聚合物基体之间界面相互作用进行定量的研究,而且关于这方面的报道也较少。本文利用接触角法测定了高岭土填料和尼龙6基体的表面自由能、界面张力、粘附功等热力学参数,对高岭土与尼龙6之间界面相互作用与复合材料力学性能、流变行为的关系进行了分析和探讨。 相似文献
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以共聚型氯醇橡胶(ECO)为基体, 通过在基体中溶解不同浓度的LiCF3SO3制备了一系列聚合物电解质. 利用差示扫描量热技术(DSC)研究了该体系锂盐浓度对聚合物电解质玻璃化转变温度的影响, 用傅里叶变换红外光谱(FTIR)研究了体系内锂盐与聚合物基体的相互作用. 结果表明, 在相同锂盐浓度下, ECO基聚合物电解质的室温离子电导率比传统的聚环氧乙烷(PEO)基聚合物电解质提高了2个数量级, 并且体系电导率在升降温循环测试中没有弛豫现象产生. 这是由于ECO基体的非结晶性所致. 相似文献
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Arthi Jayaraman 《Journal of polymer science. Part A, Polymer chemistry》2013,51(7):524-534
Macroscopic properties of polymer nanocomposites depend on the microscopic composite morphology of the constituent nanoparticles and polymer matrix. One way to control the spatial arrangement of the nanoparticles in the polymer matrix is by grafting the nanoparticle surfaces with polymers that can tune the effective interparticle interactions in the polymer matrix. A fundamental understanding of how graft and matrix polymer chemistries and molecular weight, grafting density, and nanoparticle size, and chemistry affect interparticle interactions is needed to design the appropriate polymer ligands to achieve the target morphology. Theory and simulations have proven to be useful tools in this regard due to their ability to link molecular level interactions to the morphology. In this feature article, we present our recent theory and simulation studies of polymer grafted nanoparticles with chemical and physical heterogeneity in grafts to calculate the effective interactions and morphology as a function of chemistry, molecular weights, grafting densities, and so forth. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献
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We demonstrate a complete procedure for simulations of electric field poled polymeric nonlinear optical systems with the purpose to evaluate the macroscopic electro-optic coefficients. The simulations cover the electric field poling effects on the chromophore order at the liquid state, the cooling procedure from the liquid to the solid state in the presence of the poling field, and the back-relaxation of the system after the removal of the field. We use Disperse Red chromophore molecules doped in a poly(methyl methacrylate) matrix for a numerical demonstration of the total procedure. On the basis of the simulation results, the polymer mobility and the static properties of the dopant chromophores are derived. In the liquid state, the chromophore molecules are closer to the side chains than to the backbones of the polymer matrix, and after the simulated annealing, the polymer matrix tends to be closely packed, leading to a significant change in the polymer structure around the chromophore molecules. Besides predicting the absolute macroscopic electro-optic coefficient values, the results are used to derive the microscopic origin of these values in terms of geometric and electronic structure, loading, poling, and back-relaxation effects, thereby aiding to establish design principles for optimum guest-host configurations. 相似文献
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Active fiber composites are electromechanical actuators based on piezo-ceramic fibers, which are embedded in a polymer matrix. The fibers are electrically contacted through so-called interdigitated electrodes (IDEs). State-of-the-art metallic IDEs only contact the fibers at two small sections of their circumference at the top and bottom of the composite ply, respectively. This paper presents an original technique to manufacture IDEs made of a conducting polymer (polypyrrole/p-toluene sulfonic acid), where the polymer electrodes contact the fibers around their whole circumference. The necessary process steps are discussed, namely design of the master electrodes and electrochemical polymer growth with and without fibers. Processing issues are discussed and solutions are suggested. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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《高分子科学杂志,C辑:聚合物评论》2013,53(1):53-85
Abstract Polymer modeling plays a vital role in industrial product and process development. Polymer modeling is an integral component of the research and development paradigm at The Dow Chemical Company. The integrated multidisciplinary and multiscale modeling paradigm implemented at Dow is reviewed first in this article. Overviews are then provided of polymer modeling performed in the context of seven different Dow projects, namely: mechanical properties of thermoplastic polymers; polymer/clay nanocomposites; polyol templating; flow induced crystallization and polymer process modeling; polymer design via high‐throughput modeling; linear, branched, and/or network chain architectures; and water vapor transport in a polymer matrix composite. 相似文献
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The key factors in the design of nanocomposites include obtaining a good adhesion between components and homogeneous dispersion of the nanoadditive in the polymer matrix. Direct mixing of graphene with polymers which are then processed by melt compounding method results in strong tendency of nanoadditive to agglomerate. The article presents a new approach to obtaining poly(vinylidene fluoride)/graphene (PVDF/rGO) nanocomposites in the form of fibers. This method is characterized by the use of graphene oxide (GO) dispersed in the plasticizer instead of graphene. The combination of the fibers forming process with simultaneous reduction of GO to rGO allowed the authors to obtain nanocomposites with graphene homogeneously dispersed in the polymer matrix. Moreover, addition of graphene resulted in formation of β-phase in the nanocomposites, which is characteristic for PVDF and responsible for pyroelectric and piezoelectric properties of this polymer. 相似文献
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Shin-ichi Hirano Toshinobu Yogo Wataru Sakamoto Seiji Yamada Tomoyuki Nakamura Tomoe Yamammto Hiroyuki Ukai Kouichi Banno Tomoko Nakafuku Yukari Ando 《Journal of Sol-Gel Science and Technology》2003,26(1-3):35-41
Nano sized crystalline particles/polymer hybrids were synthesized form designed metal-organic precursors. The newly developed method is composed of the synthesis of organic matrix by polymerization and the in situ nucleation and growth of crystalline oxide particles in the organic matrix below 100°C. The design of metal-organic precursor modified with polymerizable ligand and the selection of reaction conditions does influence the size and crystallinity of ceramic particles in organic matrix. The nano-sized magnetic particle/polymer hybrid exhibits the interesting feature of superparamagnetism and quantum size effect. The crystalline particles of BaTiO3/, PbTiO3/, and KNbO3/polymer hybrids behave to be dielectric and show the typical electro-rheological behavior. 相似文献
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Connor P. Callaway Joel H. Bombile Walker Mask Sean M. Ryno Chad Risko 《Journal of polymer science. Part A, Polymer chemistry》2022,60(3):559-568
The design of polymer-based organic semiconductors that offer mechanical deformability while maintaining efficient semiconducting characteristics remains a significant challenge. Recent synthetic efforts have incorporated small alkyl segments directly into otherwise π-conjugated polymer backbones to enhance processability, mechanical deformability, and other properties. The resulting polymers can be used as stand-alone materials or as matrix polymers in complementary semiconducting polymer blends offering reasonable charge-carrier transport properties, thermal healing, and deformability. Here, a family of diketopyrrolopyrrole-tetrathiophene variants is explored via large-scale atomistic molecular dynamics simulations to examine the effect of alkyl segments incorporated into the polymer backbone on the polymer structure, dynamics, and thermal properties. Longer alkyl segments lead to polymer chains that are more flexible, compact, and mobile, with lower glass transition temperatures for the condensed phase. 相似文献
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Shen J Liu J Gao Y Cao D Zhang L 《Langmuir : the ACS journal of surfaces and colloids》2011,27(24):15213-15222
By focusing on the grafted nanoparticles (NPs) embedded in polymer melts, a detailed coarse-grained molecular dynamics simulation is adopted to investigate the effects of the grafting density, the length of the matrix and grafted chains on the dispersion of the NPs. We have employed visualization snapshots, radial distribution functions (RDFs), the interaction energy between NPs, the number of neighbor NPs, and the conformation of the brush chains to clearly analyze the dispersion state of the grafted NPs. Our simulated results generally indicate that the dispersion of the NPs is controlled by both the excluded volume of the grafted NPs and the interface between the brushes and the matrix. It is found that increasing grafting density or grafted chain length leads to better dispersion, owing to larger excluded volume; however, increasing the length of the matrix chains leads to aggregation of NPs, attributed to both a progressive loss of the interface between the brushes and the matrix and the overlap between brushes of different NPs, intrinsically driven by entropy. Meanwhile, it is found that there exists an optimum grafting density (σ(c)) for the dispersion of the NPs, which roughly obeys the following mathematical relation: σ(c) is proportional to N(m)(K)/N(g)(L), where K, L > 0 and N(m) and N(g) represent the length of the matrix and grafted chain length, respectively. Considering the practical situation that the grafted brushes and the matrix polymer are mostly not chemically identical, we also studied the effect of the compatibility between the brushes and the matrix polymer by taking into account the attraction between the grafted chains and the matrix chains. In general, our comprehensive simulation results are believed to guide the design and preparation of high-performance polymer nanocomposites with good or even tailored dispersion of NPs. 相似文献
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For organic-inorganic composite materials, the spatial dispersion of inorganic fillers in the organic matrix is of great significance for designing and manufacturing high-performance composite materials. To improve the understanding of the micro-physical mechanism of the filler-reinforced polymer matrix, we studied the relationship between filler network structure and macro-mechanical properties of silicone rubber by using fluorescent labeling technology and three-dimensional (3D) visualization imaging. The experimental results showed that a good filler network structure in the polymer matrix can more effectively dissipate external mechanical energy, which generate a visible mechanical strengthening effect. Additionally, this visualization method truly reflects the macrodispersion of the filler and the evolution of the filler network structure under dynamic stress due to its non-invasive and intuitive characteristics, which provides new theoretical guidance for the design of high-performance composites. 相似文献