巯基硅溶胶对改性亚麻籽油紫外光固化反应活性的影响

用溶胶-凝胶法制备了新型的多功能巯基硅氧烷溶胶;用亚麻籽油和环戊二烯合成了可光聚合的改性亚麻籽油低聚物(NLO),并用红外光谱(FT-IR)表征了其结构。用光-差示扫描热分析(Photo-DSC)和在线红外(RT-IR)对NLO、巯基硅氧烷的紫外光固化体系的光聚合反应活性及可光聚合官能团的转化率进行了动力学研究。结果表明:巯基硅氧烷能大大提高NLO的自由基聚合速率,环烯键对硫醇十分敏感,巯基硅氧烷溶胶兼具光引发剂和交联剂的作用。

Comparison of Fe^(2+) oxidation by Acidithiobacillus ferrooxidans in rotating-drum and stirred-tank reactors

Fe2＋ oxidation by Acidithiobacillus ferrooxidans（At.ferrooxidans） under different solid contents by adding inert Al2O3 powder was examined in rotating-drum and stirred-tank reactors.The results show that the bioactivity of At.ferrooxidans in the stirred-tank is higher than that in the rotating-drum in the absence of Al2O3 powder,but the biooxidation rate of Fe2＋ decreases markedly from 0.23 g/（L·h） to 0.025 g/（L·h） with increasing the content of Al2O3 powder from 0 to 50%（mass fraction） in the stirred-tank probably due to the deactivation of At.ferrooxidans resulting from the collision and friction of solid particles.The increase in Al2O3 content has a little adverse effect on the bioactivity of At.ferrooxidans in the rotating-drum due to different mixing mechanisms of the two reactors.The biooxidation rate of Fe2＋ in the rotating-drum is higher than that in the stirred-tank at the same content of Al2O3 powder,especially at high solid content.The higher bioactivity of At.ferrooxidans can be maintained for allowing high solid content in the rotating-drum reactor,but its application potential still needs to be verified further by the sulfide bioleaching for the property differences of Al2O3 powder and sulfide minerals.

Kinetic study on carbothermic reduction of ilmenite with activated carbon

The carbothermic reduction of Panzhihua ilmenite with various additions of activated carbon was investigated byisothermal experiments over the temperature range of1373to1773K in the argon atmosphere.According to the reaction kineticsrecorded by the infrared gas analyzer,it was found that the amount of carbon addition had little influence on the reaction rates atvarious temperatures except1473K.When the reaction temperature was above the eutectic temperature of1427K of Fe?C binarysystem,part of carbon would dissolve into Fe to form a liquid phase,which made the liquid Fe as a diffusion channel of carbon todiffuse to the reaction interface.The carbothermic reduction above1573K obeyed the shrinking-core model.The mass fraction ofTiC could be determined by the standard addition technique.

Selective Removal of Nitrogen-Containing Heterocyclic Compounds from Transportation Diesel Fuels with Reactive Adsorbent

This paper presents a new selective adsorbent to remove nitrogen-containing heterocyclic compounds from model and commercial transportation diesel fuels based on characteristic reaction designed to occur in the pores of substrate.This reactive adsorbent is composed of formaldehyde,phosphotungstic acid and Santa Barbara USA(SBA)-15.The experiment was based on assumed hydroxymethylation reaction of nitrogen-containing heterocyclic compounds with formaldehyde using phosphotungstic acid as catalyst in batch and fixed-bed systems.The nitrogen concentration in the model fuel was 237.33 ng.μl-1,carbazole and toluene were used as model nitrogen-containing heterocyclic compound and solvent,respectively.The effectiveness of reactive adsorbent for removal of nitrogen-containing heterocyclic compounds from commercial 0# diesel fuel containing 224.86 ng.μl-1 nitrogen was examined in a fixed-bed reactor at 70 ℃.The results showed that nitrogen in the model fuel was very low and the nitrogen concentration in the commercial diesel reduced to 2.44 ng.μl-1.The demand for transportation fuel with ultra-low nitrogen is satisfied.

Preparation of SO_4^(2-)/TiO_2-MoO_3 Solid Superacid and Its Catalytic Activity in Acetalation and Ketalation

SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The optimum conditions were also found, that is, the mass ratio of MoO3 used in the compound is 25%, the calcination temperature 450℃, and the soaked consistency of H2SO4 is 0.5mol.L^-1. Then it was applied in the catalytic synthesis of six similar important ketals and acetals as catalyst and revealed high catalytic activity. Under the condition that the molar ratio of aldehyde/ketone to glycol was 1:1.5, the mass ratio of the catalyst to the reactants was 0.5% and the reaction time 1.0 h, the yield of ketals and acetals reached up to 63.2%. The catalyst can be easily recovered and reused.

二茂铁甲酸封端不饱和聚酯的固化及热性能研究

以乙二醇、反丁烯二酸为原料合成的不饱和聚酯作为主链,二茂铁甲酸(FCA)作为封端剂,合成了含二茂铁基的不饱和聚酯(RFc),采用红外光谱对产物结构进行了表征。采用DSC及TGA研究了不同二茂铁甲酸含量对不饱和聚酯树脂固化性能和热稳定性的影响。结果表明,随着二茂铁甲酸含量的增加,RFc树脂固化反应活性减弱,热稳定性下降。其最高放热峰温度在171～173℃,且具有比较宽的加工温度范围(152～195℃),符合模塑料固化工艺要求。树脂的耐热性较好,初始热分解温度约为340℃,N2气氛下600℃残炭率可达19.76%。