Methyl phenol cyclic silicone (MPCS) and methyl phenyl diethoxy silane (MPDS) are important materials for production of addition-cured liquid silicone rubber.The one step Grignard method was used to synthesize MPDS and the orthogonal test method was applied to optimize the process.The maximum MPDS yield of 60.2% was obtained under molar ratio of magnesium/ methyl triethoxy silane/chlorobenzene of 1/1.5/1.25,reaction time of 2.5 h and reaction temperature of 95℃.The hydrolysis and pyrolysis methods were used to synthesize MPCS and the single factor method was applied to optimize the process.The maximum MPCS yield of 72% was achieved with DBS/MPDS mass ratio of 4% and fractional addition of MPDS at 95℃.The products were characterized by infrared spectrometer and the results showed that the peaks appeared on the IR spectra were basically in agreement with those of MPDS and MPCS, respectively.
Orthogonal experiment method was used to investigate the effects of NiSO4·6H2O 、NaH2PO2·H2O、C3H6O2、H3BO3、pH and temperature on electroless Ni-P plating on quartz optical fiber surface when the combination extent between Ni-P thin film and fiber surface and Ni-P deposition rate were taken as the two objuctive functions.The optimal values of the six factors above were determined as: 35 g·L-1,32 g·L-1,20 mL·L-1,28 g·L-1,pH 5 and 84 ℃,respectively.The effect of coarsening time on film quarlity was also studied.SEM,SM,ICP and XRD were used to characterize and analyze the morphology,composition and structure of Ni-P film,respectively.The results showed that the Ni-P film deposited under the selected pretreatment conditions and the optimal electroless plating conditions has qualified properties with smoother and lucent surface,good combining force and without falling off after thermal shock test.
The osmosis was introduced in electroless plating process for simultaneous deposition of Pd-Ag in this experiment.A ceramic supported Pd/Ag inorganic composite membrane with thickness of 8 μm and compositions of 76.4Pd-23.6Ag(at.%) was prepared.More attention was focused on the effects of osmosis on the deposition speed,compositions,surface structure properties of the simultaneously deposited Pd-Ag alloy top layer by electroless plating.The experiment shows that the introduction of osmosis into electroless plating can increase the co-deposition speed,improve the densification and increase the combination extent of the film,but does not obviously influence its compositions.The hydrogen permeability coefficient and H 2/N 2 separation factor of the film are 3.07×10 -12 moL·cm/cm 2·s·pa 0.5 and 4 000 at 350 ℃ and 0.3 MPa, respectively.
Electroplating method was used to prepare a thick nickel layer on the Ni-P coating deposited on the surface of quartz optical fiber.The effects of the concentrations of nickel sulfate and sodium dodecyl sulfate and current density on the nickel deposition rate and coating quality were mainly investigated and the their suitable values were determined.The rare earth of lanthanum oxide(La2O3) with mass concentration of 1.5g·L-1 was added into the Watt electroplating bath to improve the electroplating effect.Scanning Electron Microscopy and Stereomicroscope were employed to characterize and analyze the surface morphology of the prepared thick Ni layer.The results showed that the addition of rare earth La2O3 in Watt bath reduced the metal grain size and improved the densification of the metal layer and made the sample(thickness of about 800μm) have high hardness,strong adhesion,low resistivity,high density and good solderability.
Microwave-Assisted Hydro Distillation (MAHD) and conventional Hydro Distillation (HD) are compared and evaluated in terms of extraction time, extraction yield, chemical composition, quality of the essential oil and operation consumption. Experiments results manifest that MAHD has no obvious advantage over traditional HD for the extraction of Dwarfed Cinnamomum Camphora var. Linaolifera Fujita (D-CCLF) twigs. Extraction of essential oils from D-CCLF leaves with MAHD is superior with regard to extraction time (37.5 min vs. 120 min), extraction yield (1.73 vs. 1.71%) and operation cost (0.21 k Wh/g of essential oil vs. 0.67 kWh/g of essential oil). The chemical composition and quality of the extracted essential oils by using the two methods are quite similar to each other, indicating that the utilization of microwave irradiation would not cause an adverse influence on them. Therefore, MAHD is a fast and energy-saving method for the essential oils extraction of D-CCLF leaves.
Taking the typical three-tube co-current ammonia synthesis reactor in a middle-size ammonia synthesis plant of our country as an example, the mathematical models of the reactor were employed to simulate the reactor operation calculation. The calculated sensitive parameters of inlet temperature, outlet temperature, inlet vacant velocity and outlet ammonia molar fraction of the catalyst bed and the daily ammonia output can be compared with those measured in industrial production to simply and quickly determine the catalyst active (coefficients) during different production periods,which has an important significance to instruct industrial (ammonia) production and ammonia synthesis reactor design.
The study on producting iron oxide from mother solution containing ferrons chloride is reported.This article discusses that the Fe 2O 3 percentage and oil absorbancy of iron oxide and gain size of FeCO 3,α-FeOOH,α-Fe 2O 3 are changed with different operation parameters ,and also discusses the speed rate of oxiding reaction.
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