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821.
Leila Ahmadian-Alam Vahid Haddadi-Asl Hossein Roghani-Mamaqani Leila Hatami Mehdi Salami-Kalajahi 《Journal of Polymer Research》2012,19(1):9773-12
Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) was employed to synthesize
well-defined poly (styrene-co-butyl acrylate)/clay nanocomposites. Dodecyltrimethylammonium bromide (DDTMAB) and Vinylbenzyltrimethylammonium
chloride (VBTMAC) surfactants were used as clay modifier. The classical surfactant is used to expand the interlayer gallery
of montmorillonite; however, double bond of reactive modifier participates in chain propagation process and forms clay-attached
polymer chains. Subsequently synthesis of attached and free poly (styrene-co-butyl acrylate) chains and their composition
was confirmed by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR). Narrow distribution of nanocomposites molecular weight was confirmed by gel permeation chromatography (GPC). Partially
exfoliated clay layers in the copolymer matrix were revealed by X-ray diffraction (XRD) and transmission electron microscopy
(TEM). Thermal properties of the nanocomposites were evaluated by differential scanning calorimetry (DSC) and thermogravimetric
analysis (TGA). Thermal decomposition of the nanocomposites was hindered in the presence of nanoclay. Dynamic mechanical thermal
analysis (DMTA) results show that addition of nanoclay was also resulted in enhanced storage modulus (E′) in comparison with
the neat copolymer. Lower glass transition temperature of nanocomposites was displayed by DSC. 相似文献
822.
Alireza Khataee Amirreza Khataee Mehrangiz Fathinia Behrouz Vahid Sang W. Joo 《Journal of Industrial and Engineering Chemistry》2013,19(6):1890-1894
To well describe the photoassisted-electrochemical process for treatment of the contaminated water, a new kinetic model was established based on the intrinsic reactions of the process. The kinetic model correlated apparent kinetic constants to operational parameters including applied current, initial dye concentration and flow rate. Degradation experiments were carried out with boron-doped diamond (BDD) anode and carbon nanotubes–polytetrafluoroethylene (CNTs–PTFE) cathode. The proposed kinetic model was validated by the experiments of C.I. Acid Blue 92 degradation in aqueous solution. The goodness of fitting (R2 = 0.96) demonstrated that the new model could describe both the kinetics and the hydrodynamics of the photo-electrochemical system. 相似文献
823.
Mojgan Hashemzehi Vahid Pirouzfar Hamed Nayebzadeh Chia-Hung Su 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2022,97(1):111-119
In this research, the modeling of Cu0.4Zn0.6Al2O4 catalysts performance and optimizing of esterification reactions were considered by the central composite design (RSM) response method. The main independent parameters of temperature, the ratio of alcohol to oil, the amount of catalyst and time duration have been considered for setting the esterification process. To access the maximum activity in the esterification process, the optimum conditions are estimated at 10.42 the molar ratio of alcohol to oil, 2.98 wt.% for the amount of catalyst at the temperature of 163.37 °C and within 4.15 hrs. Under these conditions, the conversion will be above 97.94%. These conditions have been applied to adjust the process of transesterification of waste cooking oil. The reusability of the Cu0.4Zn0.6Al2O4 nanocatalyst in the esterification reaction was investigated in this study. Employed statistical techniques and developed models can be employed as a useful tool for design, prediction, and optimization of the biodiesel production process with effective performance for various industrial applications. © 2021 Society of Chemical Industry (SCI). 相似文献
824.
Vahid Sendijarevic Aisa Sendijarevic Kurt C. Frisch Paul Reulen 《Polymer Composites》1996,17(2):180-186
Polyoxazolidone composites were prepared from polymeric isocyanate (PAPI 901) and epoxides (Epon 828 and DEN 431) in the presence of an oxazolidone-forming catalyst, triphenylantimony iodide. The effects of isocyanate to epoxide equivalent ratio, type of epoxide, and amount of fiberglass reinforcement on the composite properties were studied as well as the effects of post-curing temperature and time. Increasing the fiberglass content of the polyoxazolidone composites resulted in an improvement of the thermal and mechanical strength properties. The heat deflection temperature of all polyoxazolidones was > 250°C. The retention of the tensile strength at 150°C was excellent, ∼90% or higher. Polyoxazolidone composites based on DEN 431 at 1.2 isocyanate to epoxide equivalent ratio with 70 wt.% of fiberglass and post-cured at 150°C for 48 h exhibited the best properties. According to the results of DMA, TMA and DSC, the maximum operating temperature for polyoxazolidone composites is around 200°C. The TGA data showed that the decomposition temperature was ∼330°C. 相似文献
825.
In this study, the possibility of simultaneous acid‐demineralization and enzymatic desizing of cotton fabric in acidic conditions (pH 2) by using industrial acid stable enzymes has been investigated. Acid‐demineralization is necessary to remove undesired cationic metals and earth alkalis. Our experiments showed that by use of a mixture of two appropriate enzymes, a glucoamylase (Multifect GA 10L) and an α‐amylase (Optisize Next) in a solution of citric acid and presence of a chelating agent, enzymatic desizing, and acid‐demineralization can be successfully carried out at the same time. Therefore, two processes of pretreatment were integrated into a single process, which can effectively reduce time and costs for textile industry. 相似文献