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1.
Within the framework of fractal analysis and percolation theory, an alternative model of reinforcement of filled polymers
is offered. Practically, this model can be used only to describe the reinforcement of nanocomposites, because, according to
the treatment considered, a pronounced reinforcement can be reached only at ratios of filler particle diameter to the statistical
segment length of about 10 and less. A theoretical calculation showed a good qualitative and quantitative agreement with experiments.
The type of reinforcement mechanism of composites is determined by the type of the space (fractal or Euclidean) in which the
structure of the polymeric matrix is formed.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 6, pp. 797–802, November–Decem ber, 2006. 相似文献
2.
Ying‐Hung So Pamela Foster Jang‐Hi Im Philip Garrou Jack Hetzner Edmund Stark Kayla Baranek 《Journal of polymer science. Part A, Polymer chemistry》2006,44(5):1591-1599
Divinylsiloxane‐bisbenzocyclobutene (DVS‐bisBCB) polymer has very low dielectric constant and dissipation factor, good thermal stability, and high chemical resistance. The fracture toughness of the thermoset polymer is moderate due to its high crosslink density. A thermoplastic elastomer, polystyrene–polybutadiene–polystyrene triblock copolymer, was incorporated into the matrix to enhance its toughness. The cured thermoset matrix showed different morphology when the elastomer was added to the B‐staged prepolymer or when the elastomer was B‐staged with the DVS‐bisBCB monomer. Small and uniformly distributed elastomer domains were detected by transmission electron micrographs (TEM) in the former case, but TEM did not detect a separate domain in the latter case. A high percentage of the polystyrene–polybutadiene–polystyrene triblock copolymer could be incorporated into the DVS‐bisBCB thermoset matrix by B‐staging the triblock copolymer with the BCB monomer. The elastomer increased the fracture toughness of DVS‐bisBCB polymer as indicated by enhanced elongation at break and increased K1c values obtained by the modified edge‐lift‐off test. Elastomer modified DVS‐bisBCB maintained excellent electrical properties, high Tg and good thermal stability, but showed higher coefficient of linear thermal expansion values. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1591–1599, 2006 相似文献
3.
Osamu Sangen Singo Masuda Hidehiko Nakano Kazusige Yamana Kenichi Sasaki Naoki Ikeda 《Journal of polymer science. Part A, Polymer chemistry》1992,30(6):1171-1175
A new synthetic pathway of A–B–A tri-block copolyether which is composed of a hydrophilic poly(oxyethylene) unit as an A part and a hydrophobic poly(oxy-2-methyl-trimethylene) unit as a B part is proposed. Telechelic α-tosyl-ω-tosyloxypoly(oxy-2-methyl-trimethylene) derived from tosylation of poly(oxy-2-methyl-trimethylene glycol) (PMTG) was allowed to react with poly(ethylene glycol) (PEG) in the presence of sodium hydroxide. Tg of the resulting A–B–A tri-block copolyether (PEMG) (M?n = 1600) was ?72°C and its specific gravity [D415] was 1.055. 相似文献
4.
Electrically conductive heterogeneous binary polymer blends based on ethylene-propylene-diene-monomer (EPDM) and polyaniline (PAni) were prepared in a Haake Rheocord 90 rheometer, coupled with an internal mixer (counter rotating cam rotors) using different amounts of PAni doped with dodecylbenzenosulfonic acid (DBSA). Blends were crosslinked using two methods: (i) phenolic resin (SP-1045) as crosslinking agent and (ii) electron beam irradiation. The last method avoids the interference of the acid dopant in the crosslinking process and produces blends with higher conductivity. 相似文献
5.
交联助剂对PPC/NBR弹性体结构和性能的影响 总被引:2,自引:1,他引:2
研究了马来酸酐(MA)及异氰脲酸三烯丙酯(TAIC)对聚丙撑碳酸酯/丁腈橡胶共混弹性体结构和性能的影响,发出加入MA或TAIC能有效地改善交联网络;加入适量MA能显著改善共混弹性体热氧老化稳定性;加入TAIC使共混弹性体具有优良的高弹特性和力学性能。 相似文献
6.
The distribution coefficients of oil and curing agent in PP/EPDM TPV were calculated by measuring the melting point of the PP phase using differential scanning calorimetry (DSC). The PP/EPDM TPV was prepared by using a twin screw extruder and a peroxide curing agent was used. The peroxide induces the degradation of PP, resulting in the decrease of Tm. The oil in PP phase also decreases the Tm. Based on the Tm difference among pure PP and PP/EPDM TPV before and after extraction by cylcohexane, the calculated oil distribution coefficient is 0.537. The addition sequence of PP, oil, and curing agent has a significant effect on the Tm and the calculated curing agent distribution coefficient is 0.52. Both of the coefficients are less than 1. Based on the calculation of the two coefficients, a rationale design of thermoplastic vulcanizate (TPV) can be made by proper control of raw materials, addition sequence, and processing parameters. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
7.
It is well known that, with respect to the director, nematic elastomers can be macroscopically aligned by uniaxial mechanical fields. Extending this method to a chiral smectic C elastomer, depending on the experimental set-up either smectic layer orientation or director orientation parallel to the stress axis occurs. In order to align the director and the smectic layers a biaxial mechanical field (e.g. shear field) consistent with the phase symmetry has to be used to achieve a macroscopically uniform orientation of the untwisted smectic C* structure. 相似文献
8.
基于介电弹性体的软机器在柔性机器人、能量收集、柔性电子等领域有着广泛的应用.传统的介电弹性器件由不透明的流体碳膏电极或其他硬材料制作的电子导体来驱动.可拉伸透明离子导体作为电极驱动介电弹性体时,两种软材料互相结合,为软机器提供了一种独特的实现方式.论文综述了离子导体驱动的介电弹性体软机器的近期研究进展,展望了未来的研究方向和存在的问题. 相似文献
9.
10.
We investigated the structure-property relationship of nematic liquid crystalline elastomer (LCE) actuators obtained from a series of nematic side-on monomers. The liquid crystalline acrylate monomers were designed and synthesized with different tail lengths. Combining a soft lithography technique with photo-polymerization/photo-crosslinking of aligned nematic liquid crystalline monomers and crosslinkers, nematic LCE micropillars were obtained, based on the new monomers. Through microscopic observation, influence of some structural parameters on the thermo-mechanical behavior of the micropillars was investigated. The thermo-mechanical behavior of the LCEs showed a close correlation with to the tail length of the monomer and the spacer length of the crosslinker. 相似文献