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11.
Laura Fedele Francesco Pernechele Sergio Bobbo Mauro Scattolini Roman Stryjek 《Fluid Phase Equilibria》2009
In this paper, solubility measurements of CO2 in pure pentaerythritol tetraoctanoate (PEC8) between 273 and 343 K are presented. The experiments were performed according to the static, synthetic method. The data are represented using the Peng–Robinson equation of state with the Huron–Vidal mixing rules and the UNIQUAC equation for the excess Gibbs Energy (gE) at infinite pressure. This system shows immiscibility in liquid phase, with lower critical end point (LCEP) at T = 268 ± 0.1 K and xCO2=0.98±0.001 and upper critical end point (UCEP) at the critical point of pure CO2. 相似文献
12.
Characterization of electron-beam-modified surface coated clay fillers and their influence on physical properties of rubbers 总被引:3,自引:0,他引:3
Sudip Ray Anil K. Bhowmick K. S. S. Sarma A. B. Majali V. K. Tikku 《Radiation Physics and Chemistry》2002,65(6):627-640
A novel process of surface modification of clay filler has been developed by coating this with an acrylate monomer, trimethylol propane triacrylate (TMPTA) or a silane coupling agent, triethoxy vinyl silane (TEVS) followed by electron beam irradiation. Characterization of these surface modified fillers has been carried out by Fourier-transform infrared analysis (FTIR), electron spectroscopy for chemical analysis (ESCA), wettability by dynamic wicking method measuring the rise of a liquid through a filler-packed capillary tube and water flotation test, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Presence of the acrylate and the silane coupling agent on the modified fillers has been confirmed from FTIR, ESCA, and EDX studies, which has also been supported by TGA studies. The contact angle measurement by dynamic wicking method suggests improvement in hydrophobicity of the treated fillers, which is supported by water flotation test especially in the case of silanized clay. However, XRD studies demonstrate that the entire modification process does not affect the bulk properties of the fillers. Finally, both unmodified and modified clay fillers have been incorporated in styrene butadiene rubber (SBR) and nitrile rubber (NBR). Rheometric and mechanical properties reveal that there is a definite improvement using these modified fillers specially in the case of silanized clay compared to the control sample, probably due to successful enhancement in interaction between the treated clay and the base polymer. 相似文献
13.
SYNTHESIS AND STRUCTURE OF MACROPOROUS MA-TMPTA COPOLYMERS AND THEIR APPLICATION IN ADSORPTION OF FLAVONOIDS FROM GINKGO LEAVES EXTRACT 总被引:4,自引:0,他引:4
SHI Zuoqing XU Mancai FENG Lili XU Mingcheng SHI Rongfu FAN Yunge HE Binglin 《Chinese Journal of Reactive Polymers》2000,(1)
1 INTRODUCTIONAdsorption by macroporous polymeric adsorbents is one of tile important methods inpurification of ginkgo leaves extract ill. Amberlite XAD-7, a macroporous polymeric adsorbentbased on methyl methacrylate - trimethylolpropane triacrylate copolymer, was reported to use inadsorptive purification of ginkgo leaves extract and other natural products containing flavonoidsfi.3]. Interaction between the adsorbent and flavonoids is based on hydrogen bonding between theester carbonyl-… 相似文献
14.
Photoinitiated crosslinking of EPDM/inorganic filler blends and characterization of related properties 总被引:1,自引:0,他引:1
<正>Photoinitiated crosslinking of ethylene-propylene-diene terpolymer(EPDM) blends filled with calcium carbonate, talc and calcined kaolin(CK) in the presence of benzil dimethyl ketal as photoinitiator and trimethylolpropane triacrylate as crosslinker and their related properties have been studied by different analytical methods.The results from gel content and heat extension determination show that the efficiency of photocrosslinking of EPDM increases with increasing the content of diene and its molecular weight.The EPDM blends with 100 phr different inorganic fillers can be photocrosslinked to gel content of above 60%by 5 s UV-irradiation under optimum conditions.Under the same conditions of irradiation,the orders of photocrosslinking rate and final gel content are EPDM/CaCO_3EPDM/talcEPDM/CK.The data from thermogravimetric analysis,dynamic mechanical thermal analysis,electrical properties,mechanical tests and scanning electron microscopy show that UV irradiation crosslinking apparently enhances the thermal stability,mechanical properties and electrical properties of the photocrosslinked EPDM/inorganic filler samples.Although the attenuated total-reflection FTIR data show that inorganic fillers can promote the surface photo-oxidation of EPDM/inorganic filler samples with increasing the irradiation time,the above related properties of the photocrosslinked EPDM blends irradiated within 5 s are enough to satisfy many applications in the cable industry. 相似文献
15.
J. Bretagne F. Epaillard A. Richard 《Journal of polymer science. Part A, Polymer chemistry》1992,30(2):323-328
The F and CF2–CF2+ excited states have been detected by emission spectroscopy in CF4RF plasmas used for TMPTA polymerization. These excited states are related through electron collision to F and CF2 ground states. The temporal variation of the F and CF2–CF2+ radiative states near the substrate reveals that the F atoms disappear first by incorporation in the monomer during the polymerization phase and, then, by a third body recombination process enhanced by the polymer surface. The CF2–CF2+ radiative states are varying as the inverse of the F states indicating a strong destruction mechanism of CF2 radicals by F atoms. 相似文献
16.
Antonio Razzouk Ilham Mokbel Josefa García Josefa Fernandez Nizar Msakni Jacques Jose 《Fluid Phase Equilibria》2007,260(2):248-261
Vapor pressures of four pure pentaerythritol esters, PE, pentaerythritol tetrapentanoate, pentaerythritol tetraheptanoate, pentaerythritol tetranonanoate and pentaerythritol tetra 2-ethylhexanoate were measured between 334 and 476 K in a recently developed gas saturation apparatus. The experimental vapor pressure values for the four polyolesters range from 5.6 × 10−5 Pa to 0.94 Pa. These data together with density values were used to determined SAFT and PC-SAFT characteristic parameters. The linearity of molecular parameters for both models with the molecular weight permits to interpolate and extrapolate these parameters for pentaerythritol ester with linear chains. For pentaerythritol esters with ethyl-alkanoic chains, the parameters of SAFT and PC-SAFT have been estimated assuming that the slope of these straight lines is the same for PEs with linear chains that for PE with branched chains. This procedure was used to predict density of commercial POEs, estimating the molecular weight when it is not available from the viscosity at 313.15 K. PC-SAFT gives better performances than SAFT to predict density data for these four compounds at high pressures and for other PEs at atmospheric pressure. Furthermore, characteristic parameters for Soave-Redlich-Kwong and Peng Robinson EoSs were also estimated from the experimental vapor pressures and literature density values. 相似文献
17.
季戊四醇四硝酸酯晶体能带结构和起爆机理的DFT研究 总被引:4,自引:0,他引:4
对季戊四醇四硝酸酯(PETN)晶体进行DFT-B3LYP计算,求得其晶格能为-1.000eV,与实验值相近.前沿能带平坦,表明分子轨道能态受分子晶体场的影响较小.硝基O原子的较大贡献和酯O原子的较小贡献共同组成价带上沿态密度,而空带下沿则由硝基O和硝基N原子共同组成,说明-NO2基易于接受电子.O-C键的重叠布居数明显比所有其它键的小,加之O-C键鞍点偏离其中点0.022nm,表明该键易于优先异裂起爆.由重叠布居数可知,分子间O…H存在较小的相互作用,[110]方向的撞击将使O…H距离靠近,因而相互作用加强,还使O-C键上的电子向O原子转移,并大大减小该键的重叠布居数,因而促进了该键的异裂. 相似文献
18.
19.
Summary A rapid and convenient method for the full O-alkylation of pentaerythritol was investigated. The method involves an alkyl
halide in a polar aprotic solvent, in the presence of sodium hydroxide. The optimal reaction conditions were studied for methyl
iodide, ethyl iodide and bromide, n-propyl bromide and n-butyl bromide. Methyl and propyl derivatives were quantitatively
obtained in a short reaction time. The method was applied for the gas chromatographic—mass spectrometric analysis of a commerical
pentaerythritol sample. 相似文献
20.
Neutralized flame retardant phosphorus agent: Facile synthesis, reaction to fire in PP and synergy with zinc borate 总被引:1,自引:0,他引:1
A neutralized intumescent fire retardant (NIFR) has been synthesized in “one step and one pot” using a simple, novel and safe protocol. The fire retardant efficiency of the NIFR in polypropylene (PP) has been evaluated using usual fire testing methods. The results show that the NIFR is very effective. Moreover, we demonstrate that zinc borate exhibits a synergistic effect on fire retardant properties and apparently prevents migration of the additives through the polymer matrix. 相似文献