The technology for preparation of sodium polyacrylate with molecular weight at 4000 is as following: the dose of catalyzer is at 8.8%, the concentration of initiator is 5.2%, the concentration of monomer is 38.7% by the total weight of reactant and the reaction temperature can be controlled at 30-40℃.
The complex shape green body of hexagonal boron nitride obtained by Gel-Casting forming technology is studied in this paper, it is focused on effect of organic monomer content and proportion on colloid character, collide gelling behavior of slurry added initiator, effect of activator on gel gelling performance, effect of monomer and initiator content on green body gelling character as well as.
A new environmentally friendly catalyst, H4SiW12O40-polyaniline (PAn), was prepared, and n-butyraldehyde 1,2-propanediol acetal was synthesized from n-butyraldehyde and 1,2-propanediol in the presence of H4SiW12O40-PAn.
The influence factors of the synthesis were discussed, and the best reaction conditions were found: the molar ratio of n-butyraldehyde to 1,2-propanediol is 1:1.5, the amount of catalyst used is 1.2% of feed stock, and the reaction time is 1.0 h.
H4SiW12O40-PAn is an excellent catalyst for synthesizing n-butyraldehyde 1,2-propanediol acetal, and the yield can reach more than 95.2%.
The partial intermediate products were absorbed on TiO2 surface, which resulted in catalyst deactivation.
But when it was irradiated under UV illumination or solar irradiation for some time, the catalyst could be reused without loss of catalytic activity.
Based on the polymer and plastic analogy, the annual market for products that carry nano-components, including all computer chips, half of pharmaceuticals and half of chemical catalysts, will reach $1 trillion by 2015.
The results showed that the catalyst had higher catalytic performance than common hydrogenation catalysts.
The conversion of CNB could reach 99.9%, and the dechlorination of chloroaniline (CAN) was less than 1.9% when catalyzed by Pt-Sn-B/CNTs and more than 8.0% when catalyzed by common hydrogenation catalysts.
Exploitation of rare earth catalysts in polymer syntheses
The studies over forty years on rare earth catalysts in polymer syntheses of diene, alkyne, alkylene oxide, thiirane, carbon dioxide copolymerization, lactide, caprolactone, cyclic carbonate and so forth in China have been reviewed.
Thermomechanical instability in steady operating regime of continuous-flow chemical reactor with fixed catalyzer bed
A continuous-flow chemical reactor with fixed bed is a vessel filled with a porous catalyzer through which a liquid or gaseous reagent mixture is filtered.
Acetylene and hydrogen were used in the CVD process with Fe-catalyzer at 700°C under 250 Pa.
The growth properties of the CNT array film can be achieved by controlling the structure of the template, the particle size of Fe-catalyzer, the temperature in the reactor, the flow ratio and the deposition time.
A new C60 derivative-hydroxylated fullerene epoxide [C60 (OH)x(O)y] was prepared by the reaction of C60 benzene solution with aqueous NaOH and H2O2 in the presence of tetrabutylammonium hydroxide (TBAH) as the catalyzer.
The spectra indicate that the energy transfer takes place from the triplet excited state of MLCT (metal-to-ligand charge transfer) state for Sr2CeO4 (sensitizer) to the rare earth ions (activator).
In conclusion, all results indicate that BeDREB1 and BeDREB2 genes isolated from treated Bermuda grass are new members of the DREB transcription activator family, which may play very important roles in signal transduction related to stresses.
Reporter gene assays show that ZNF322 is a potential transcriptional activator.
A fragment of Penicillium canescens genomic DNA carrying the xlnR gene coding for a translational activator of xylanolytic genes was isolated.
canescens major secreted enzymes-β-galactosidase and α-L-arabinofuranosidase-appeared weakly dependent on the translational activator xlnR.