Controllable ring‐opening polymerization of trimethylene carbonate catalyzed by aliphatic tertiary amines in the presence of benzyl alcohol or F127

With the increased awareness of avoiding residue metals, the field of organocatalysts is attracting more attention. Aliphatic tertiary amines, such as triethylamine (TEA), N, N, N, N‐tetramethylethylenediamine (TMEDA) and 1,1,4,7,7‐pentamethyldiethylenetriamine (PMDTA), have low boiling points which allow their easy elimination after a chemical reaction. Here, we used these aliphatic tertiary amines to catalyze ring‐opening polymerizations (ROPs) of trimethylene carbonate (TMC). In the presence of benzyl alcohol, the catalytic activities of the tertiary amines were in the order of TEA < TMEDA < PMDTA. Correlation between the molecular weight of polycarbonates and monomer conversions was linear, suggesting the polymerization was controlled. The polymerization pathway was presumed to follow an alcohol‐activated mechanism according to the end‐group fidelity determined using ¹H NMR spectroscopy. The ROP of TMC was also successfully initiated by PEO₉₉‐PPO₆₅‐PEO₉₉ (F127) under the catalysis of the tertiary amines, producing well‐defined PTMC_n‐F127‐PTMC_n copolymers with narrow dispersity ( ca 1.2) and with thermosensitive properties in aqueous solution. Furthermore, copolymerizations of TMC with acryloyl‐containing cyclic carbonate were catalyzed by the tertiary amines in the presence of F127. No crosslinking reactions were detected. Our results demonstrate that the aliphatic tertiary amines have the potential to catalyze TMC homo‐ or copolymerization featuring controllable structure and composition under mild conditions. Copyright © 2012 Society of Chemical Industry     

Well‐Defined Functional Linear Aliphatic Diblock Copolyethers: A Versatile Linear Aliphatic Polyether Platform for Selective Functionalizations and Various Nanostructures

Low‐temperature anionic ring‐opening homopolymerizations and copolymerizations of two glycidol derivatives (allyl glycidyl ether (AGE) and ethoxyethyl glycidyl ether (EEGE)) are studied using a metal‐free catalyst system, 3‐phenyl‐1‐propanol (PPA) (an initiator) and 1‐tert‐butyl‐4,4,4‐tris(dimethylamino)‐2,2‐bis[tris‐(dimethylamino)phosphoranylidenamino]‐2Λ⁵,4Λ⁵‐catenadi(phosphazene) (t‐Bu‐P₄) (a promoter) in order to obtain well‐defined functional linear polyethers and diblock copolymers. With the aid of the catalyst system, AGE is found to successfully undergo anionic ring‐opening polymerization (ROP) even at room temperature (low reaction temperature) without any side reactions, producing well‐defined linear AGE‐homopolymer in a unimodal narrow molecular weight distribution. Under the same conditions, EEGE also undergoes polymerization, producing a linear EEGE‐homopolymer in a unimodal narrow molecular‐weight distribution. In this case, however, a side reaction (i.e., chain‐transfer reaction) is found to occur at low levels during the early stages of polymerization. The chemical properties of the monomers in the context of the homopolymerization reactions are considered in the design of a protocol used to synthesize well‐defined linear diblock copolyethers with a variety of compositions. The approach, anionic polymerization via the sequential step feed of AGE and EEGE as the first and second monomers, is found to be free from side reactions at room temperature. Each block of the obtained linear diblock copolymers undergoes selective deprotection to permit further chemical modification for selective functionalization. In addition, thermal properties and structures of the polymers and their post‐modification products are examined. Overall, this study demonstrates that a low‐temperature metal‐free anionic ROP using the PPA/t‐Bu‐P₄ catalyst system is suitable for the production of well‐defined linear AGE‐homopolymers and their diblock copolymers with the EEGE monomer, which are versatile and selectively functionalizable linear aliphatic polyether platforms for a variety of post‐modifications, nanostructures, and their applications.     

Application of LS-SVM strategy to estimate H2S loading capacity in different ionic liquids and alkanolamines

Favorable properties of aqueous solutions are improved with the addition of different materials for separation of hydrogen sulfide (H₂S). Also, equilibrium data and available equations for solubility estimation of this gas are only valid for specific solutions and limited ranges of temperature and pressure. In this regard, a machine learning model based on Support vector machine (SVM) algorithm is proposed and developed with mixtures containing different amines and ionic liquids to predict H₂S solubility over wide ranges of temperature (298–434.5 K), pressure (13–9319 kPa), overall mass concentration (3.82–100%) and mixture's apparent molecular weight (18.39–556.17 g/mol). The accuracy of the performance of this network was evaluated by regression analysis on calculated and experimental data, which had not been used in network training.     

离去基团法制备端氨基聚醚的研究进展

通过对端氨基聚醚的概述，介绍了离去基团法制备端氨基聚醚的合成方法和研究情况，并且对离去基团法制备端氨基聚醚的研究方向进行了探讨，以推广端氨基聚醚的应用。     

A Study on Glutaric Acid Extraction by Tridodecylamine: Equilibria and Models

The extraction of glutaric acid was studied using tridodecyl amine (TDA) with respect to the functional groups of the diluent. The diluents studied were 1‐octanol (alcohol), methyl isobuthyl ketone, MIBK (ketone), and toluene (aromatic hydrocarbon) and these were used to dilute the TDA. The experimental results of batch extraction experiments are reported as distribution coefficients, D_C, loading factors, Z, and extraction efficiency, E. All measurements were carried out at 298.15 K. The results of the liquid‐liquid equilibrium measurements are correlated by a linear solvation energy relationship (LSER) model that takes into account physical interactions and modified Freundlich and Langmuir equations. The experimental results are compared with model results.     

深层水平井双聚胺基钻井液技术研究与应用

针对大庆油田深层致密气埋藏深,储层砾岩、火山岩裂缝发育,水敏性强,钻井过程中易发生漏失、垮塌、缩径及高温钻井液性能变差等复杂,且深层水平井钻进会带来摩阻、携岩和储层污染及使用油基钻井液存在成本高、后期环保压力大等难题,在分析总结前人研究成果及经验基础上,从致密气藏地质特征及深层水平井钻井难点出发,明确了钻井液技术对策,通过开展聚胺和聚醚多元醇"双聚"抑制、封堵防塌剂的研究,配合自主研制的新型高效随钻封堵材料,研发出一套适合于深层致密气藏水平井施工的双聚胺基钻井液技术。室内研究及现场应用表明,该钻井液具有较强的封堵防塌、井眼清洁和润滑防卡能力,抗温达180℃以上,有效地解决了深层水平井漏失、垮塌、携屑、润滑问题和储层保护问题,保证了深层水平井的顺利施工,创造了大庆油田深层水平井钻井周期最短(109d),井深最深(5048 m),水平段最长(969.22 m),井底温度最高(180℃)等几项新纪录,完全满足了徐家围子地区深层致密气藏的钻探需求,为深层水平井安全、快速、高效钻井提供了技术保障。     

胺液中N-甲基二乙醇胺含量的测定

由于天然气净化厂脱硫胺液中含有甘醇类降解产物,二甘醇（DEG）和三甘醇（TEG）难于准确称量,以DEG或TEG为内标物的毛细管气相色谱法测定胺液中MDEA的含量时,会产生较大的误差。为避免这种影响,建立了以甲苯为内标物的毛细管气相色谱测定法：选用美国Agilent HP-50+毛细管柱来分析胺液中甲基二乙醇胺（MDE）的含量;定量方法为内标法;对三甘醇（TEG）和甲苯进行分析对比,最终选用甲苯作为内标物;使用MINITAB 15.1处理实验数据。实验结果表明：MDEA和甲苯出峰稳定,重复性好;方法回收率为99%~101%,相对标准偏差<2%。该法精密度和准确度较高,不仅可用于天然气净化厂胺液中MDEA含量的测定,而且对同类胺液的MDEA含量测定研究也有一定的借鉴作用。     

纸浆废液接枝共聚脂肪族减水剂的试验研究

对由纸浆废液制备的木质素磺酸盐与脂肪族减水剂接枝共聚合成木聚脂肪族减水剂进行了试验研究.通过红外光谱分析对减水剂分子共聚反应进行表征,按照单因素法进行工艺优化,确定了最佳合成工艺参数.性能测试结果表明,制得的木聚脂肪族减水剂具有良好的分散性和保塑性,综合性能优于脂肪族减水剂和物理复配减水剂.     

Organochlorine Formation in Tertiary Amine Catalyzed Pulp Bleaching

An oxygen delignified eucalyptus kraft pulp was bleached by applying a catalytic amount of a tertiary amine, 1,4-diazabicyclo[2,2,2]octane, and hypochlorous acid at varying pH, temperature, and time. The bleaching filtrate was analyzed for chloroform and AOX and the pulp for residual lignin, hexenuronic acid, and OX. In comparison with chlorine dioxide bleaching, the novel catalytic bleaching (pH < 6) generated only traces of chloroform and low contents of AOX and OX. Separate catalytic oxidations of authentic hexenuronic acid showed that it was a major precursor of chloroform. The results demonstrate a practical way to reduce organochlorine formation in pulp bleaching and provide new understanding on the reaction pathways that yield chloroform.