镁合金磷化工艺及磷化后涂层的性能研究

研究了AZ31镁合金—磷化膜的形成过程、工艺和配方,并推测成膜离子磷酸根和锌离子等主要是在阳极附近结晶成长,进而覆盖合金表面。从而设计了合理的四层防护装饰涂层体系,并对其进行了性能检测。结果显示:涂膜的附着力达到1级,400 h的中性盐雾实验可达2级,说明该涂层体系对镁合金有较好的防护作用,磷化膜可以提高镁合金与有机涂层的结合力与耐腐蚀性。     

环氧树脂灌封器件电镀前处理工艺改进

针对环氧灌封器件表面镀层结合力差的问题,在镀前对环氧树脂灌封体进行喷砂,并将铬酸酐?硫酸体系化学粗化改为等离子粗化.采用改进的前处理工艺后,环氧树脂灌封体表面的镀层厚度、结合力及可靠性均满足宇航型号产品的使用要求.     

Mechanism analysis of solvent selectivity and energy-saving optimization in vapor recompression-assisted extractive distillation for separation of binary azeotrope

Octane and p-xylene are common components in crude gasoline, so their separation process is very important in petroleum industry. The azeotrope and near azeotrope are often separated by extractive distillation in industry, which can realize the recovery and utilization of resources. In this work, the vapor–liquid equilibrium experiment was used to obtain the vapor–liquid equilibrium properties of the difficult separation system, and on this basis, the solvent extraction mechanism was studied. The mechanism of solvent separation plays a guiding role in selecting suitable solvents for industrial separation. The interaction energy, bond length and charge density distribution of p-xylene with solvent are calculated by quantum chemistry method. The quantum chemistry calculation results and experiment results showed that N-formylmorpholine is the best solvent among the alternative solvents in the work. This work provides an effective and complete solvent screening process from phase equilibrium experiments to quantum chemical calculation. An extractive distillation simulation process with N-formylmorpholine as solvent is designed to separate octane and p-xylene. In addition, the feasibility and effectiveness of the intensified vapor recompression assisted extraction distillation are also discussed. In the extractive distillation process, the vapor recompression-assisted extraction distillation process is globally optimal. Compared with basic process, the total annual cost can be reduced by 43.2%. This study provides theoretical guidance for extractive distillation separation technology and solvent selection.     

高分子阻燃剂溴化聚苯乙烯的应用

以高分子溴化聚苯乙烯(BPS)协同三氧化二锑(Sb2O3)作为复合阻燃剂,对聚对苯二甲酸丁二醇酯(PBT)进行改性。研究了复合阻燃剂对PBT的燃烧性能,电性能及力学性能的影响。结果表明,复合阻燃剂BPS/Sb2O3对PBT具有良好的阻燃效果,对其电性能影响很小,少数力学性能有所下降。在PBT中添加BPS/SbO复合阻燃剂的质量分数为20%时,阻燃PBT的垂直燃烧达到FV-0级。     

压制参数对TATB基PBX膨胀特性的影响

对采用不同工艺参数(压力、药温)压制成型的TATB基PBX药柱进行了热循环试验。研究了压制参数对TATB基PBX药柱膨胀特性的影响,并对其影响机理进行了分析。结果表明,在药温恒定(110℃)条件下,增加压制压力,药柱轴向高度的不可逆膨胀增大,而药柱体积的不可逆膨胀却减小;压力恒定(170M Pa)时,降低药温,药柱轴向高度和整体体积的不可逆膨胀都有所减小。分析认为这是由于不同压制参数导致成型过程晶体取向度不同和晶体破碎程度不同所引起的。     

相容剂对PA6/POE力学性能和微观结构影响

转矩流变仪中熔融法制备了苯乙烯(St)和甲基丙烯酸缩水甘油酯(GMA)或甲基丙烯酸羟乙酯(HEMA)分别接枝乙烯-辛烯共聚物(POE),并将接枝物用于聚酰胺6(PA6)增韧改性.结果表明:2种接枝物POE-g-(GMA-co-St)和POE-g-(HEMA-co-St)的最佳反应加工时间分别为8.0 min和10.0 min,二者均能明显改善PA6与POE之间的相容性,但是前者增韧效果更好,其改性共混物力学性能更优.     

磷酸八钙的制备方法与应用

磷酸八钙是骨、齿的主要成分之一,是羟基磷灰石的重要前驱体,具有良好的生物相容性和生物活性,是较好的骨替换材料。本文综述了磷酸八钙合成研究的最新进展,重点介绍和评述了磷酸八钙的合成与制备方法,分析了各种制备方法的特点,并对其在生物医用材料方面的应用进行了阐述。     

Isoparaffin production by aqueous phase processing of sorbitol over the Ni/HZSM-5 catalysts: Effect of the calcination temperature of the catalyst

Ni/HZSM-5 catalysts calcined at different temperatures were used in the isoparaffin production by aqueous phase processing of sorbitol and characterized by N₂ physical adsorption, temperature-programmed reduction (H₂-TPR), temperature-programmed desorption of ammonia (NH₃-TPD) and Raman techniques. The effect of calcination temperature of the catalysts on the catalytic performance for the reaction was investigated. The activity test results indicated that the maximal i-C₆H₁₄ selectivity of 45.4% and the total i-C₆H₁₄ and i-C₅H₁₂ yield of 32.3% were obtained over the catalyst calcined at 500 °C, which exhibited the optimum surface area and pore structure with 100% of the reducibility of Ni species on the surface of HZSM-5. In addition, the amount and the strength distribution of acidic surface sites of the catalyst decreased with the increase of calcination temperature at 500 °C above. All these factors result in an increase in the formation of isoparaffin.     

雷达吸波涂料用混合环氧树脂固化动力学研究

采用傅里叶红外光谱法(FT-IR)和示差扫描量热法(DSC)对雷达吸波涂料用混合型环氧树脂的固化反应历程进行了研究.由温度-升温速率外推法确定了该体系的起始固化温度、峰顶固化温度和终止固化温度为分别为60.55℃、97.0℃和131.79℃,为固化工艺的确定提供了依据;由Kisserger方程求得共聚体系固化反应的表观活化能为65.6kJ/mol;根据Crane理论求得固化反应级数为0.91,接近于1级反应;通过Arrhenius公式求得不同升温速率下固化反应的速率常数K,随着升温速率的升高,K值由0.276增大到0.983,反应速度显著加快.     

热氧处理聚丙烯粉料DSC结晶参数研究

给出了一种采用DSC结晶参数评估聚丙烯回收料降解程度的方法。实验结果表明,随着热氧处理时间的增加,结晶峰温（Tpc）、外推结晶起始温度（Teic）、结晶起始温度（Tic）和结晶热焓（ΔHc）都逐渐下降,且呈现出较好的规律性。可以利用这种规律对聚丙烯回收料的降解程度做定量评估。