萃取精馏分离三甲氧基硅烷和甲醇的模拟和优化

运用Aspen Plus对萃取精馏分离三甲氧基硅烷和甲醇进行了模拟研究。采用芳烃作溶剂,通过和传统的对二甲苯溶剂对比,发现异丙苯和均三甲苯作溶剂具有很好的节能效果,且均三甲苯效果十分显著。在均三甲苯作溶剂的基础上,分析了溶剂比、塔板数、进料位置、回流比等条件对分离效果的影响,并对参数进行优化。确定了最优的操作条件为萃取精馏塔共24块理论板,混合物进料位置为第15块塔板,溶剂进料位置为第11块板,溶剂比为0.4,回流比为0.6。溶剂回收塔共12块理论板,进料位置为第5块塔板,回流比为2.3。在此条件下,三甲氧基硅烷和甲醇的产品的质量分数均能达到99.6%。     

固相萃取-电感耦合等离子体质谱法测定钢铁冶炼工业废水中铊

准确测定钢铁冶炼工业废水中铊,对钢铁冶炼排出的工业废水进行源头监测和控制铊污染具有重要意义。因钢铁冶炼工业废水盐分较高且铊含量较低,基体效应较为显著,故实验以γ-氨乙基氨丙基三甲氧基硅烷(KH792)改性纳米二氧化硅材料作为吸附剂,用固相萃取技术对铊离子进行分离富集,以2.0 μg/L ¹⁰³Rh作为内标,²⁰⁵Tl作为检测对象,建立了电感耦合等离子体质谱法(ICP-MS)测定钢铁冶炼工业废水中铊的方法。优化后的固相萃取条件如下:吸附pH值为8.5,吸附时间为15 min,样品体积为40 mL,吸附速率为1.5 mL/min,用5.0 mL 1.0 mol/L硝酸以0.5 mL/min的速率进行洗脱,富集倍数为8。在优化的实验条件下,在铊的质量浓度为0.10~10.0 μg/L范围内,以铊质量浓度为横坐标,铊信号强度与铑内标元素强度的比值为纵坐标,绘制校准曲线,其线性相关系数为0.999 9。检出限为0.002 3 μg/L,定量限为0.007 7 μg/L。将实验方法应用于钢铁冶炼工业废水中铊的测定,结果的相对标准偏差(RSD,n=7)为0.55%~2.8%,加标回收率为93%～101%。将实验方法应用于模拟钢铁冶炼工业废水中铊的测定,测定值与理论值基本一致。     

甲基三氯硅烷的综合利用

简述了甲基三氯硅烷在甲基三甲氧基硅烷、甲基三乙氧基硅烷、甲基三乙氧然硅烷、甲基硅树脂、甲基苯基硅树脂、甲基硅酸钠等有机硅产品制备中的应用,以及这些有机硅产品的用途。     

Polybenzoxazine containing polysilsesquioxane: Preparation and thermal properties

Benzoxazine bearing trimethoxylsilane (BA‐b) was successfully synthesized via Mannich condensation among phenol, paraformaldehyde, and γ‐aminopropyltrimethoxysilane. The hydrolysis and condensation of the BA‐b catalyzed by hydrochloric acid can afford a soluble polysilsesquioxane bearing benzoxazine groups (denoted PSSQ‐b). By initiating the cocuring reaction of PSSQ‐b with difunctional benzoxazine of bisphenol A (BA‐a), the inorganic–organic hybrids of polybenzoxazine with polysilsesquioxane were prepared. The hybrids displayed enhanced T_g's in comparison with the control polybenzoxazine. In terms of initial decomposition temperature (T_d) and char and ceramic yields, the hybrids exhibited improved thermal stability as shown by thermogravimetric analysis (TGA). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 927–936, 2006     

Influence of POSS modifier on NLO properties of the hybrid materials

The sol-gel-based nonlinear optical (NOL) mate-rials can be divided into two classes: (1) the guest-host-doped systems and (2) the chromophore boned tomain-chain hybrids[1, 2]. The intrinsic problems in thefirst class are the weak interactions between guest andhost parts. This issue can be solved by linking NLO-ac-tive organic chromophores to the inorganic matrix (thesecond class). One of the various methods to fabricatethis class of the NLO hybrid materials is when the de-sired chromophor…     

Nano-indentation profiles of intrinsic hardness and modulus of films based on silsesquioxane modified with titanium tetrabutoxide

This study is to analyze the influence of the modifier, 5 -25 wt % titanium tetrabutoxide (TBO),on the hardness and elastic modulus of the films based on SSO deriving from hydrolytic condensation of (3-glycidoxypropyl) trimethoxysilane (GPMS) and vinyltrimethoxysilane (VMS), by the continuous stiffness measurement (CSM) technique of an instrumented-indentation testing (ⅡT) device. Films were synthesized by adding the stoichiometric amount of ethylenediamine (EDA) and benzoyl proxide (BPO) to SSO solutions in ethanol, dip-coating over glass substrates, and curing using an appropriate thermal cycle. Intrinsic values of hardness and elastic modulus were determined with the average values in “plateau region” from “four-layer”explanation. And the brittle index of the modified coating systems was analyzed.     

有机高分子絮凝剂P(DMDAAC-VTMS)和P(DMDAAC-AM-VTMS)的合成及絮凝性能研究

采用水溶液自由基聚合方式,用复合引发剂引发聚合,得到了P（DMDAAC-VTMS）和P（DMDAAC-AM-VTMS）;探讨了BTMS的投料比对聚合物的特性粘度和水溶性的影响;并对这两种絮凝剂的除浊和脱色性能做了初步研究。实验中发现;VTMS的引入使P（DMDAAC-VTMS）和P（DMDAAC-AM-VYMS）的特性粘度分别比PDMDAAC和P（DMDAAC-AM）的特性粘度略微增大,但其水溶性变差;在絮凝性能方面,P（DMDAAC-VTMS）和P（DMDAAC-AM-VTMS）的除浊和脱色性能分别较PDMDAAC和P（DMDAAC-AM）有了提高。     

Proton Conductive Membranes from Covalently Cross-Linked Poly(Acrylate)/Silica Interpenetrating Networks

The preparation of hybrid proton conductive membranes that comprise of covalently linked interpenetrating polymer and inorganic networks is reported. The hybrid membranes are synthesized via simultaneous photo-initiated polymerization and sol–gel processing. The simultaneous processing permeates fabrication of the membranes that comprises covalently cross-linked polymeric and inorganic networks. The membranes are characterized by attenuated total reflectance-Fourier transform infrared spectroscopy, scaning electron microsopy, thermogravimetric analysis, differential scanning calorimetry, in order to confirm their chemical composition, structure, and morphology. An addition of 3-methacryloxypropyl trimethoxysilane into the sol–gel composition allows the formation of covalent linkages between polymeric and inorganic networks, which facilitates a uniform distribution of the molecular components across the fabricated membranes. The incorporation of the silica network leads to an increase in water retention and proton conductivity of hybrid membranes as compared to their purely polymeric analogues.