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接枝改性木纤维对聚氯乙烯/木纤维复合材料力学性能的影响 总被引:4,自引:0,他引:4
接枝改性木纤维对聚氯乙烯/木纤维复合材料力学性能的影响廖兵,黄玉惠,赵树录,林果,丛广民(中国科学院广州化学研究所广州510650)关键词木纤维,聚氯乙烯/木纤维复合材料,接枝木纤维可作塑料的增强填料,但它与塑料的界面亲合性差,须进行改性,改善表面亲... 相似文献
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稀土元素表面处理对玻璃纤维填充金属—塑料多层复合材料冲击磨损性能的影响 总被引:3,自引:0,他引:3
金属 塑料多层复合材料由钢背、烧结多孔青铜中间层和聚四氟乙烯 (PTFE)与填料混合物组成的表层复合而成 ,具有金属和塑料原有的优良性能 ,如高的机械性能、低的热膨胀系数和低的摩擦系数、良好的导热性和优异的减磨性[1~ 3 ] 。众所周知 ,玻璃纤维可用来提高PTFE复合材料的力学性能[4~ 6 ] 。纤维与基体之间的界面结合力起着控制聚合物复合材料力学性能的重要作用 ,并主要受纤维表面处理的影响[7~ 9] 。Watanabe[10 ] 认为只填充玻璃纤维的PTFE复合材料在水中的磨损大于其它复合材料 ,玻璃纤维易受磨损且细碎的玻… 相似文献
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评价了热致液晶高聚物作为高性能成型材料的特点。综述了由增强性的热致液晶高聚物和热塑料聚合物基体组成的原位复合材料及其制备、结构和性能。也讨论了今后研究这一塑料增强新途径时要注意的诱导取向和相容性。 相似文献
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工程塑料近二十年进展 总被引:2,自引:0,他引:2
叙述了通用工程塑料、特种工程塑料、聚烯烃复合材料及合金和ABS过去二十年进展,重点讨论了工程塑料单体新技术及新单体/新聚合物、聚合物增韧核——壳结构理论、纳米复合材料、反应器合金、长纤维增强热塑性塑料(LFT)、工程塑料回收及产业动态。 相似文献
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Adsorption of methylene blue onto jute fiber carbon: kinetics and equilibrium studies 总被引:5,自引:0,他引:5
Senthilkumaar S Varadarajan PR Porkodi K Subbhuraam CV 《Journal of colloid and interface science》2005,284(1):78-82
Jute fiber obtained from the stem of a plant was used to prepare activated carbon using phosphoric acid. Feasibility of employing this jute fiber activated carbon (JFC) for the removal of Methylene blue (MB) from aqueous solution was investigated. The adsorption of MB on JFC has found to dependent on contact time, MB concentration and pH. Experimental result follows Langmuir isotherm model and the capacity was found to be 225.64 mg/g. The optimum pH for the MB removal was found to be 5-10. The kinetic data obtained at different concentrations have been analyzed using a pseudo-first-order, pseudo-second-order equation, intraparticle diffusion and Elovich equation. Among the kinetic models studied, the intraparticle diffusion was the best applicable model to describe the adsorption of MB onto JFC. 相似文献
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Prafulla K. Sahoo Pradeep K. Rana Nandalal Deb Sarkar Anusmita Sahoo Sarat K. Swain 《Journal of polymer science. Part A, Polymer chemistry》2003,41(17):2696-2703
Jute fiber (Corchorus capsularis, JRC‐321 variety), an environmentally and ecologically friendly product, was chemically modified by the cooking alkaline sulfite process to unbleached and bleached pulps, which were further modified via graft copolymerization with acrylamide monomer with a complex initiating system: CuSO4/glycine/KHSO5. The above samples were characterized and morphologically analyzed by IR, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and X‐ray diffraction. The biodegradability and superabsorbency of the samples were also evaluated for their novel commercial importance as jute‐based superabsorbents. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2696–2703, 2003 相似文献
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Haydaruzzaman Ruhul A. Khan Mubarak A. Khan A.H. Khan M.A. Hossain 《Radiation Physics and Chemistry》2009,78(11):986-993
Jute fabrics-reinforced polypropylene (PP) composites (50% fiber) were prepared by compression molding. Composites were fabricated with non-irradiated jute fabrics/non-irradiated PP (C-0), non-irradiated jute fabrics/irradiated PP (C-1), irradiated jute fabrics/non-irradiated PP (C-2) and irradiated jute fabrics/irradiated PP (C-3). It was found that C-3 composite performed the best mechanical properties over other composites. Total radiation dose varied from 250–1000 krad and composites made of using 500 krad showed the best results. The optimized values (C-3 composites) for tensile strength (TS), bending strength (BS) and impact strength (IS) were found to be 63 MPa, 73 MPa and 2.93 kJ/m2, respectively. 相似文献
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Rigid polyurethane foams based on liquefied bagasse and reinforced with jute fibre were prepared. The effects of preparation conditions were investigated using a paper cup with a small horizontal section area as a mould. They were reflected in the foam height, which acted as a sensitive indicator. Density gradient existed in the foam rise direction and decreased from the bottom to top. Although the amount of blowing agent water was fixed, the foam height increased with stirring time after the addition of diphenyl methane diisocyanate, the isocyanate index and the catalyst content. This was partly due to the released heat that also contributed to the foam expansion. The relative intensity of the C─N stretching band at 1510 cm−1 and the N─H out-of-plane bending band at 1527 cm−1 in the FTIR spectrum reflected isocyanate reactions, which had a close relationship with the crosslink density. The normalized compressive strength was essentially attributed to the combined effects of the crosslink density and the thickness of cell walls and struts. Jute fibre enhanced the compressive strength only slightly due to poor interfacial adhesion between some fibres and the matrix. 相似文献
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Shaik Inayath Basha Dr. Md. Abdul Aziz Prof. M. Maslehuddin Prof. Shamsad Ahmad 《化学:亚洲杂志》2021,16(23):3914-3930
Jute stick, one of the most commonly and abundantly available agricultural waste product, was converted to a value-added submicron/nano jute carbon by using pyrolysis and high-energy ball milling techniques. The submicron/nano jute carbon was characterized using FE-SEM, TEM, EDS, XRD, XPS and Raman spectroscopy. The anticorrosive performance of the submicron/nano jute carbon was investigated through electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and salt spray techniques, on mild steel plates coated with a mixture of epoxy resin and the submicron/nano jute carbon. The electrochemical impedance of the steel coated with the composite coating was two orders of magnitudes higher than that of the specimen coated with neat epoxy. Consequently, the corrosion rate of specimens coated with composite coating was 13–20 times higher than that of steel coated with neat epoxy coating. The salt spray results also indicate an improvement in the corrosion resistance performance of the composite coating compared to the neat epoxy. The uniform distribution of the submicron/nano jute carbon particles in the epoxy resin improved the denseness of the composite coating by acting as a barrier against the diffusion of chloride, moisture, and oxygen, thus, improving the corrosion resistance of the developed coating. 相似文献
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Baljinder K. Kandola S. Ilker Mistik Wiwat Pornwannachai A. Richard Horrocks 《Molecules (Basel, Switzerland)》2021,26(15)
Biocomposites comprising a combination of natural fibres and bio-based polymers are good alternatives to those produced from synthetic components in terms of sustainability and environmental issues. However, it is well known that water or aqueous chemical solutions affect natural polymers/fibres more than the respective synthetic components. In this study the effects of water, salt water, acidic and alkali solutions ageing on water uptake, mechanical properties and flammability of natural fibre-reinforced polypropylene (PP) and poly(lactic acid) (PLA) composites were compared. Jute, sisal and wool fibre- reinforced PP and PLA composites were prepared using a novel, patented nonwoven technology followed by the hot press method. The prepared composites were aged in water and chemical solutions for up to 3 week periods. Water absorption, flexural properties and the thermal and flammability performances of the composites were investigated before and after ageing each process. The effect of post-ageing drying on the retention of mechanical and flammability properties has also been studied. A linear relationship between irreversible flexural modulus reduction and water adsorption/desorption was observed. The aqueous chemical solutions caused further but minor effects in terms of moisture sorption and flexural modulus changes. PLA composites were affected more than the respective PP composites, because of their hydrolytic sensitivity. From thermal analytical results, these changes in PP composites could be attributed to ageing effects on fibres, whereas in PLA composite changes related to both those of fibres present and of the polymer. Ageing however, had no adverse effect on the flammability of the composites. 相似文献
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介绍了几种薄层色谱展开方法,包括中途展开、接力展开、多维接力展开、改进二维展开等,还介绍了一种简单的下行展开的操作方式以及关键部件的制作方法。 相似文献
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本文通过研究肼感染显影动力学,对肼感染显影的显影速度及其活化能进行测试和计算,籍以讨论有关肼感染显影过程的机理。实验结果表明:肼感染显影的早期是直接显影,活化能低;后期是灰化成核显影,活化能高;而低曝光量潜影核无灰化成核显影,活化能较高。高反差、短趾部的形成原因是由于显影加速和显影抑制的竞争结果。 相似文献
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Stephan Küppers 《Accreditation and quality assurance》1997,2(7):338-341
The analytical chemists in process development in the pharmaceutical industry have to solve the difficult problem of producing
high quality methods for purity determination and assay within a short time without a clear definition of the substance to
be analyzed. Therefore the quality management is very difficult. The ideal situation would be that every method is validated
before use. This is not possible because this would delay the development process. A process-type quality development approach
with an estimation type fast validation (measurement uncertainty) is therefore suggested. The quality management process consists
of the estimation of measurement uncertainty for early project status. Statistical process control (SPC) is started directly
after measurement uncertainty estimation and a classical validation for the end of the project. By this approach a process
is defined that allows a fast and cost-efficient way of supporting the development process with the appropriate quality at
the end of the process and provides the transparency needed in the development process. The procedure presented tries to solve
the problem of the parallelism between the two development processes (chemical and analytical development) by speeding up
the analytical development process initially.
Received: 25 March 1997 · Accepted: 17 May 1997 相似文献