苯乙烯制造技术的研究及工业化前景

介绍了乙苯催化脱氢制苯乙烯催化剂及其工艺的发展概况 ,对有工业化前景的新工艺进行了探讨。发现开发低温节能型催化剂是催化脱氢法未来的发展方向 ,Smart工艺和乙苯氧化脱氢工艺是值得推荐的具有发展前途的苯乙烯制造新技术。

β-Cyclodextrin Promoted Oxidation of Cinnamaldehyde to Natural Benzaldehyde in Water

A facile and efficient procedure has been developed systematically for the oxidative cleavage of cinna-maldehyde to benzaldehyde by sodium hypochlorite with water as the only solvent in the presence of β-cyclodextrin （abbreviated as β-CD）. Different factors influencing cinnamaldehyde oxidation e.g. reaction temperature, the amount of catalyst and oxidant, have been investigated. The yield of benzaldehyde reaches 76% under the optimum conditions （333 K, 4 h, molar ratio of cinnamaldehyde to β-CD is 1：1）. Furthermore, a feasible reaction mecha-nism including the formation of benzaldehyde and the two main byproducts （phenylacetaldehyde and epoxide of cinnamaldehyde） has been proposed.

Hydrogen-bonding Interaction of 1,2,3-triazine-waters Complexes

Density functional theory B3LYP method with 6-31＋＋G＊＊ basis was used to optimize the geometries of the ground states for 1,2,3-triazine-（H2O）n（n=1,2,3） complexes. All calculations indicate that the 1,2,3- triazine-water complexes in the ground states have strong hydrogen-bonding interaction, and the complex having a N… .H-O hydrogen bond and a chain of water molecules which is terminated by a O. … .H-C hydrogen bond is the most stable. The H-O stretching modes of complexes are red-shifted relative to that of the monomer. In addition, the Natural bond orbit （NBO） analysis indicates that the intermolecular charge transfer between 1,2,3-triazine and water is 0.0222e, 0.0261e and 0.0273e for the most stable 1：1, 1：2 and 1：3 complexes, respectively. The first singlet （n, π＊） vertical excitation energy of the monomer 1,2,3-triazine and the hydrogen-bonding complexes of 1,2,3-triazine-（H2O）n were investigated by time-dependent density functional theory.

Study on the prediction of visible absorption maxima of azobenzene compounds

The geometries of azobenzene compounds are optimized with B3LYP/6-311G* method, and analyzed with nature bond orbital, then their visible absorption maxima are calculated with TD-DFT method and ZINDO/S method respectively. The results agree well with the observed values. It was found that for the calculation of visible absorption using ZINDO/S method could rapidly yield better results by adjusting OWFπ-π (the relationship between π-π overlap weighting factor) value than by the TD-DFT method. The method of regression showing the linear relationship between OWFπ-π and BLN-N (nitrogen-nitrogen bond lengths) as OWFπ-π=?8.1537+6.5638BLN-N, can be explained in terms of quantum theory, and also be used for prediction of visible absorption maxima of other azobenzne dyes in the same series. This study on molecules’ orbital geometry indicates that their visible ab- sorption maxima correspond to the electron transition from HOMO (the highest occupied molecular orbital) to LUMO (the lowest unoccupied molecular orbital).

Hydroxylation of phenol with hydrogen peroxide catalyzed by Fe- and AIFe-Bentonite

The paper described pillarisations of natural bentonite from Pacitan East Java of Indonesia by using AI and Fe. Intercalation process by using surfactant molecule has also been carried out. Natural bentonite was intercalated with HDTMA-Br （hexadecyltrimethylammonium-bromide） 1, 5% solution before pillared with AI and Fe metal to give HDTMA-bentonite forms. The ratio of bentonite and intercalating agent or pillaring agent was 1 gr/50 mL. The mixture was agitated, and then the solid phase was washed with distilled water. Then it was dried and calcined at 450℃ for 4 hours. Their catalytic activity and selectivity were studied for phenol hydroxylation using tlzOz （30%）. The reaction condition of this reaction was as follows： ratio of phenol/ H202 = 1：1 （molar ratio）, concentration of phenol = 1 M, reaction temperature was 60℃, and ratio of catalyst/phenol was 1：10. The products were hydroquinone and cathecol.

Experimental Investigation on Promoting Effect of Composite Promoting Agents on Natural Gas Hydrate Formation

An experiment on effects of composite promoting agents composed of surfactants and liquid hydrocarbons on hydrate formation was conducted and the hydrate formation temperature,pressure,induction time and rate in the presence of different composite promoting agent packages were measured.The surfactants used covered sodium dodecyl sulfate(SDS),sodium dodecyl benzene sulfonate(SDBS) and 2-octyl sodium dodecyl sulfate(GC20S),and the liquid hydrocarbon additives utilized included cyclopentane(CP) and methyl cyclohexane(MCH).It appeared that all these combinations of composite promoting agents could promote hydrate formation.The type II hydrate formation conditions using composite promoting agents composed of CP and GC20S were the mildest and the induction time was the shortest;whereas the type H hydrates formation conditions using composite promoting agents composed of MCH and GC20S were the mildest and the induction time was also the shortest.

Grafted Deproteinized Natural Rubber as an Impact Modifier in Styrene-Methyl Methacrylate Copolymer Sheet

This research was studied to prepare styrene-methyl methacrylate copolymer sheet （S-co-MMA sheet） by using DPNR （deproteinized natural rubber） as an impact modifier. The DPNR was prepared by adding SDS （sodium dodecyl sulfate） into the HANR （high-ammoniated natural rubber latex） and followed by centrifugation. It was found that DPNR was successfully prepared with the lowest nitrogeneous content about 0.034±0.01% w/w by adding SDS for 1.00 phr and centrifugation at 12,000 rpm. Then DPNR was grafted with styrene and methyl methacrylate （DPNR-g-S/MMA） obtained by emulsion polymerization. The effects of DPNR-g-S/MMA were studied by varied the amount of SDS and redox initiator. From this result the grafting efficiency DPNR-g-S/MMA was higher than that of NR-g-S/MMA. The DPNR-g-S/MMA was used as an impact modifier in S-co-MMA sheet. Furthermore, the appropriate quantities of styrene monomer and DPNR-g-S/MMA were also investigated. While DPNR-g-S/MMA was used as impact modifier in S-co-MMA sheet, the result was shown DPNR-g-S/MMA improve impact strength of S-co-MMA sheet. Scanning electron micrographs of S-co-MMA sheet with DPNR-g-S/MMA was found the smooth fracture surface. Thus impact strength of S-co-MMA/gDPNR sheet was high and physical properties of S-co-MMA/gDPNR sheet could be able to be accepted in industry. Concisely, DPNR-g-S/MMA can be used as an impact modifier in S-co-MMA sheet.

Improving the Abrasion Resistance of ＂Green＂ Tyre Compounds

Since the introduction of＂green tyres＂ in the early 90＇s, the use of silica as a reinforcing filler, along with a silane coupling agent, has spread and grown worldwide. The greatest advantage of using silica over carbon black as reinforcing filler in a tyre tread compound is that a lower rolling resistance is achieved, while maintaining good wet traction. However, a previous study has shown that the wear resistance of a silica filled ENR （epoxidised natural rubber） compound was not as high as those of conventional OESBR （oil extended styrene butadiene rubber） and NR/BR compounds used in passenger car and truck tyre treads. In this work, with the aim of improving abrasion resistance, the effect of blending BR （butadiene rubber） into a silica filled ENR compound was studied. Blends with 0 to 30 phr BR were prepared in a Polylab Haake internal mixer. The rheological properties of the compounds were measured using a Mooney viscometer and oscillating-disc rheometer. The hardness, tensile strength and DIN abrasion resistance were also measured. The results showed that the ENR/silica compound properties such as tensile strength and hardness were as good as those of the conventional compounds. However, the most important finding was that abrasion resistance increased significantly with BR content, exceeding that of the conventional compound at BR： ENR ratios of greater than 20：80.

Good dispersion of hydrophilic nanoscale silica in rubber matrix and the effects on rubber nanocomposites

Using the industrial technologies of rubber latex irradiation,preparation of nanoscale silica(SiO2) slurry,mixing irradiated rubber latex with SiO2 slurry,and the spray drying,we have prepared the ultrafine fully-vulcanized powder carboxyl styrene-butadiene rubber(UFPCSBR)/SiO2 nanocompound powder,in which the SiO2 particles and UFPCSBR particles are isolated and stuck each other.When the UFPCSBR/SiO2 nanocompound powder is mixed with crude rubber,the UFPCSBR particles are dispersed well in rubber matrix because of their good compatibility,then the SiO2 particles are also dispersed well in rubber matrix because of the carrier nature of the UFPCSBR particles during the mixing procedure,and the novel rubber/UFPCSBR/SiO2 nanocomposites are fabricated.Compared with the rubber composites prepared by mixing the crude rubber with the UFPCSBR powder and SiO2 powder one after the other,the novel UFPCSBR/SiO2 nanocompound modified rubber/UFPCSBR/SiO2 nanocomposites have better abrasion resistance,higher tensile strength and tear strength,and lower heat build-up data.Noteworthily,the tanδ-temperature curve of the novel rubber/UFPCSBR/SiO2 nanocomposites has the second tanδ peak due to the newly generated boundary layer surrounding the SiO2 particles,increasing the tanδ values in the temperature range of 0-20℃,which is very important to the research of green tyre tread.

Natural plant-derived 3,4-dihydroxybenzaldehyde ameliorates reproductive damage of male mice

In the present study,we studied the effects of 3,4-dihydroxybenzaldehyde,derived from Salvia miltiorrhiza Bunge,on mouse sperm survival and sperm membrane integrity in vitro and on mouse reproductive damage induced by cyclophosphamide in vivo.3,4-Dihydroxybenzaldehyde(0.01,0.1,and 1 mg/m L)improved sperm survival rate and sperm membrane integrity in separated mouse sperm(all P<0.05).In cyclophosphamide-treated male mice(60 mg/kg/d through intraperitoneal injection for 5 d),3,4-dihydroxybenzaldehyde(40 mg/kg/d through intragastric gavage for 35 d)increased the testis index,epididymis index,and sperm nuclear maturity(all P<0.05).3,4-Dihydroxybenzaldehyde also improved testis morphology characterized by orderly arranged layers of spermatogenic cells,numbers of sperm in the lumen,normal mesenchymal cells,and close and tidy arrangement of the seminiferous tubules.3,4-Dihydroxybenzaldehyde also increased testicular superoxide dismutase activity and elevated DJ-1 expression.In addition,it decreased the expression of ICAM-1 and enhanced the expressions of VCAM-1,PEDF,VEGF,and PPARγ.These findings indicated that 3,4-dihydroxybenzaldehyde increased mouse sperm survival and sperm membrane integrity in vitro and reduced mouse reproductive damage induced by cyclophosphamide via DJ-1 and other targets in vivo.3,4-Dihydroxybenzaldehyde might thus be useful for treating male reproductive damage and antineoplastic cyclophosphamide-induced reproductive toxicity.