离子液体中丙烯腈三元共聚的研究

采用离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)为溶剂,进行了丙烯腈(AN)、丙烯酸甲酯(MA)、衣康酸(ITA)的自由基三元共聚反应的研究。讨论了总单体浓度、引发剂含量、聚合时间、MA含量、ITA含量对共聚物相对分子质量和转化率的影响。结果表明:以离子液体[BMIM]BF4为溶剂,AN、MA和ITA可发生三元共聚,聚合物相对分子质量可达10万以上;且MA的含量可以很低直至为0,对聚合物相对分子质量影响不大;以离子液体为溶剂的共聚物的化学结构与以NaSCN水溶液为溶剂的聚合物的结构相似。     

聚丙烯腈/离子液体体系研究进展

综述了丙烯腈(AN)在离子液体中的均聚共聚、聚丙烯腈(PAN)在离子液体中的溶解机理、溶液特性以及纺丝成形的研究进展。指出以离子液体为溶剂的AN均聚和共聚反应具有反应快,聚合物相对分子质量分布窄的特点,离子液体是PAN溶解的良好溶剂;PAN/离子液体体系随温度降低呈现出可逆物理凝胶特征,PAN/离子液体具有良好的可纺性,采用干喷湿纺、静电纺丝和增塑纺丝,已制备出各种纤维;建议应进一步加强对离子液体在PAN的聚合、溶解及纺丝成形方面的研究。     

丙烯腈在离子液体中的三元共聚反应

以离子液体1-丁基-3-甲基咪唑硼酸盐([BMIM]BF4)为溶剂,研究了丙烯腈、甲基丙烯酸甲酯和衣康酸在离子液体中的自由基共聚反应。研究结果表明:衣康酸对共聚物的相对分子质量影响很大;离子液体中的共聚产物的化学结构与常规NaSCN水溶液中的聚合产物的结构基本相同,但立构规整性略低。     

丙烯酸甲酯对聚丙烯腈原丝及预氧丝结构和性能的影响

通过控制单体配比,采用丙烯酸甲酯（MA）与丙烯腈（AN）,衣康酸（IA）自由基溶液共降,以偶氮二异丁腈为引发剂在溶剂二甲基亚砚中合成了聚丙烯腈原丝纺丝溶液,并纺制了碳纤维前驱体聚丙烯腈原丝,通过IR,DSC,密度等分析手段,讨论了第二单体MA对共聚反应及聚丙烯腈原丝结构和性能及预氧化纤维的影响。实验证明：随着丙烯酸甲酯含量的增加,最后所得到的纺丝液的粘均分子量,固含量,特性粘度以及转化率都在提高,但当MA达到一定值后又降低了,MA并不是激活而是阻碍环化,与IA促进环化是矛盾的,在IA和MA之间一定有一个最好的匹配比,经过实践证明,MA质量分数为3%-4时最有利于环化和促进预氧化稳定。     

N-甲基-N＇-（2-羟基-3-乙酰氧基丙基）咪唑盐离子液体的合成

离子液体作为一种新型的绿色溶剂和催化剂已引起了化学家们的极大关注。以乙酸钠和环氧氯丙烷为起始原料首先合成了乙酸缩水甘油酯,并优化筛选了乙酸缩水甘油酯的合成条件;再与无机酸质子化的N-甲基咪唑反应,制备了四个N-甲基-N’-（2-羟基-3-乙酰氧基丙基）咪唑盐新型离子液体。采用^1HNMR,IR和UV对新型离子液体的结构进行了表征。测定了新型离子液体的电导率及与常用有机溶剂之间的溶解性能。优化筛选试验结果表明,乙酸缩水甘油酯最佳的合成条件为：乙酸钠与环氧氯丙烷的摩尔投料比为1：1.5,甲苯作溶剂,四丁基溴化铵为催化剂,回流反应7h。     

丙烯腈与衣康酸在混合溶剂中的共聚合研究

以二甲基亚砜(DMSO)和二甲基乙酰胺(DMAc)为混合溶剂,研究了丙烯腈(AN)与衣康酸(IA)的自由基共聚反应,通过红外光谱和元素分析仪等对聚合物的化学结构和组成进行了分析,并研究了DMAc的含量对单体转化率、相对分子质量及其分布的影响。结果表明:DMSO/DMAc混合溶剂所得聚丙烯腈(PAN)的化学结构与DMSO单一溶剂所得一致;随着DMAc含量的增加,PAN相对分子质量减小,相对分子质量分布逐渐增大;当DMAc溶剂质量分数小于5%时,单体转化率与使用DMSO单一溶剂时相当,且聚合物重均相对分子质量大于1.1×105,相对分子质量分布也较窄(小于3.0);DMAc的加入大大降低了PAN原液的黏度,且在低剪切速率下溶液接近牛顿流体;在DMSO中加入少量的DMAc作为混合溶剂进行PAN共聚合反应,可以减缓环化反应的作用。     

烷基链长对咪唑类离子液体-甲醇体系局部组成的影响

在全浓度范围内测定了3种离子液体-甲醇体系,即1-乙基-3-甲基咪唑四氟硼酸盐-甲醇体系、1-丁基- 3-甲基咪唑四氟硼酸盐-甲醇体系和1-己基-3-甲基咪唑四氟硼酸盐-甲醇体系的核磁共振氢谱（1H NMR）,运用局部组成模型对离子液体和甲醇的化学位移进行关联,得到了表征溶液内部微观环境的局部摩尔分数,分析了烷基链长对咪唑类离子液体-甲醇体系局部组成的影响。结果表明在这3种离子液体-甲醇体系中,离子液体的局部组成与宏观组成差异性非常小,甲醇分子在侧链越长的咪唑类离子液体中越倾向于自身缔合。     

纤维二糖在离子液体1-丁基-3-甲基咪唑氯盐中的结构动力学特性

开展分子动力学模拟探索不同压力条件下纤维素的基本结构单元--纤维二糖在离子液体1-丁基-3-甲基咪唑氯盐（[C₄mim]Cl）中的结构动力学特征。研究结果表明,高压环境使二糖分子内氢键网络结构瓦解,二糖与阴阳离子间相互作用增强,形成溶质-溶剂间氢键。借助空间分布函数得到常压及高压环境下二糖分子周围溶剂层分布特征,并通过径向分布函数定量考察了纤维二糖/离子液体体系分子间与分子内的氢键特征,为在化学键水平上认识纤维素在离子液体中溶解机制提供必要的理论基础。     

离子液体一步法催化合成4-乙酰胺基苯亚磺酸

离子液体作为一类同时具备优良溶剂性能与催化活性的新兴绿色催化剂,在各类反应当中有着广泛的应用。开发了以乙酰苯胺和SO₂为原料,采用离子液体一步法催化原料亚磺化反应合成4-乙酰胺基苯亚磺酸的新工艺,其中离子液体在反应过程中同时作为溶剂与催化剂。考察了多种离子液体一步法合成4-乙酰胺基苯亚磺酸,确定三乙胺盐酸盐/AlCl₃为最适宜离子液体,并进一步考察了三乙胺盐酸盐/AlCl₃自身物质的量配比、反应温度和反应时间等条件对其催化性能的影响;同时探讨了离子液体在反应中真正起催化作用的活性组分是[Al₂Cl₇]^-。离子液体一步法催化合成4-乙酰胺基苯亚磺酸最适宜反应条件为：反应温度为90℃、反应时间为4 h、n（三乙胺盐酸盐）：n（AlCl₃）=0.55：1.00（记为0.55Et₃NHCl/AlCl₃）。在最适宜反应条件下,液相收率达到89.55%。通过IR、LC-MS和¹H NMR等分析对产物结构进行了鉴定。     

丙烯腈与衣糠酸在混合溶剂中沉淀共聚合

采用丙烯腈（AN）与衣糠酸（IA）自由基共聚合，以偶氮二异丁腈（AIBN）为引发剂，在二甲基亚砜（DMSO）与H2O的混合溶剂中合成聚丙烯腈（PAN），讨论了反应温度、引发剂质量分数、DMSO与H2O配比、单体质量分数、IA质量分数对转化率的影响。     

Structure of coal hydrogenation products obtained in the presence of oil and coal paste-forming agents

The structure parameters of hydrogenation products were analyzed in relation to the composition of oil and coal (intrinsic) paste-forming agents used in the process of coal hydrogenation under a low pressure of hydrogen (6–10 MPa). It was found that the structure characteristics of liquefaction products essentially differed at close values of the structure unsaturation parameter δ; this was likely due to a difference in the material composition of solvents (other than aromatic structures).     

液态环氧树脂自动加压凝胶技术与配方设计

液态环氧树脂自动压力凝胶（APG技术），是国外七十年代初发展的环氧树脂快速成型工艺技术。近年来．我国的电力变压器业界从国外引进了APG技术的整套设备、配方和配套化工材料，使我国环氧树脂整体绝缘结构的品质有了大幅度的提高。APG技术可应用于薄绝缘结构（不含填料）和厚绝缘结构。当前已在我国主要的开关厂和变压器业界得到广泛的应用。     

Effect of composition on morphology structure and cell affinity of poly(caprolactone‐co‐glycolide)‐co‐poly(ethylene glycol) microspheres

Poly(caprolactone‐co‐glycolide)‐co‐poly(ethylene gylcol) copolymers (PCEG) with various composition were synthesized by copolymerization of GA, CL, and PEG. PCEG microspheres were fabricated by oil‐in‐water (o/w) emulsion and solvent‐evaporation technique. Effect of chemical composition on hydrophilicity, crystallinity, and degradation of the PCEG was investigated. It was demonstrated that morphology structure of the microspheres was greatly influenced by chemical composition and hydrophilicity of the PCEG polymer. PCEG microspheres could change from a smooth structure to a regular porous structure and an irregular structure. Moreover, the pore size of them increased with increment of PEG content and length. Cell attachment and growth on the PCEG microspheres were evaluated by using mouse NIH 3T3 fibroblasts as model cells in vitro. The result showed that the PCEG microspheres with large porous structure were more favorable for cell attachment and growth. Thus the PCEG microspheres with rapid degradation rate and large porous structure possess potential use as injectable scaffolds in tissue engineering. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42861.     

Synthesis of nylon 6-g-poly(ethylene glycol) copolymer and its compatibilizing effect in nylon 6/poly(ethylene glycol) blends

Summary A graft copolymer of poly(ethylene glycol) onto nylon 6 was prepared by two-step reactions; poly(ethylene glycol) (PEG) was chlorinated with thionyl chloride in carbon tetrachloride and the chlorinated PEG was then grafted onto nylon 6 by reacting each other with triethylamine and tin chloride in o-chlorophenol. Blends were also prepared from the graft copolymer with nylon 6 or PEG. The thermal properties and crystalline structure of the graft copolymer and the blends were studied using differential scanning calorimeter and X-ray diffractometer. It was found that the grafting of PEG onto nylon 6 changed the crystal structure of nylon 6. It was observed that compatibilization of the nylon 6/PEG blend of 50/50 composition by weight was achieved in the presence of the graft copolymer.     

癸基萘磺酸盐表面活性剂的组成-界面张力关系

该文采用廉价易得的萘和α-癸烯为原料,以氯铝酸离子液体催化Friedel-Crafts烷基化反应,合成了中间体癸基萘(DN),再经磺化与中和反应合成了结构明确、组成可调的驱油用阴离子型表面活性剂复合癸基萘磺酸钠(DNS)。中间体DN通过FTIR和1HNMR进行结构表征,产品DNS采用HPLC-MS分析组成,并测得其克拉夫特点小于0℃。测定了DNS对正构烷烃模拟油相的界面性能,结果表明,DNS1-1和DNS3均可在较低表面活性剂质量分数(0.25%～0.4%)下将油水界面张力降低至10-3mN/m数量级,并且具有良好的耐盐性,不同批次DNS1-1产品均能维持组成基本不变并稳定地重现组成相关的超低界面张力。     

The effect of hydrothermal pretreatment on the structure and fast pyrolysis behaviors of ShengLi lignite

The structure and composition of coal determine its fast pyrolysis characteristics,and the study of the relationship between them can play an important role in the efficient and clean utilization of coal.So,in this work,hydrothermal pretreatment was used to artificially change the structure and composition of ShengLi (SL) lignite,which was used to investigate the influence of structural changes on pyrolysis.The physicochemical structure and composition of samples were characterized by X-ray diffraction,specific surface area and porosity analyzer,solid-state 13C nuclear magnetic resonance,Fourier transform infrared spectroscopy,and elemental analyzer.Pyrolysis experiments were carried out in a powder-particle fluidized bed reactor,and the distribution and composition of the pyrolysis products were ana-lyzed.The gasification activity of char was investigated by thermogravimetric analysis with a CO2 atmo-sphere.The results show that hydrothermal pretreatment (HTP) can destroy the cross-linking structure of SL lignite,and affect its aromaticity,pore structure,functional group,and carbon structure to change the distribution and composition of pyrolysis products of SL lignite,especially the composition of tar.Finally,the structure-activity relationship between the structure,composition,and pyrolysis characteristics of coal was comprehensively studied.     

The effect of mixed diluent on the porous structure of crosslinked PMMA beads

Summary In this work copolymer beads, based on MMA (methyl methacrylate) and EGDM (ethylene glycol dimethacrylate), were prepared by suspension polymerization. A mixed solvent, composed of two different solvents, namely toluene and cyclohexane, was used as the diluent in the polymerization medium. The porous structure of the beads was found to be affected by the solvent composition used to dissolve the monomers initially. It was observed that the porosity and pore size increased gradually with the increase of cyclohexane content of the solvent composition. It was also detected that the pore radii changed from 2–10 nm to 700–1000 nm as the cyclohexane content of the diluent changed from nil to 100 % (v/v) respectively. These results indicate that pore size of the copolymer beads is a function of solvent composition. Received: 10 January 1999/Revised version: 15 February 2000/Accepted: 1 March 2000     

贵州大方县百纳村高岭土的理化及工艺性能研究

从矿山采集代表性的高岭土样品,球磨并过80目筛备用。利用X射线荧光光谱仪(XRF)、X射线衍射仪(XRD)、综合热分析仪(DTA-TG)、场发射扫描电子显微镜(FE-SEM)和透射电子显微镜(TEM)对高岭土的化学成分、矿物组成、理化性质与微观形貌进行了表征,并详细考察了其多项工艺性能指标。结果表明:该高岭土的主要矿物组成为多水高岭石(84.77wt%)和绿脱石(1.33wt%),具有典型的六方管状结构,管直径在十几到几十个纳米不等,管长约为几百纳米。该高岭土可塑性较好,阳离子交换容量值很高,流动性和触变性小,干燥收缩大,干燥强度较低。由于该高岭土样品的Fe2O3(0.43wt%)含量低,从而具有较高的烧成白度,1250℃下烧成样品的白度为70.8%。     

Effect of dialcohols on properties of poly(ethylene 2,6‐naphthalate) copolymers

Properties of poly(ethylene 2,6‐naphthalate) (PEN) and its copolymers containing diethylene glycol (DEG), propanediol (PD), butanediol (BD), and bisphenol A ethoxylate (BSA) were investigated. The copolymer composition was determined by ¹H‐NMR spectroscopy. It has a higher value than the feed composition due to the high volatility of ethylene glycol (EG). The melting temperature of the copolymers was gradually depressed with the increase of dialcohol in the composition. The complex viscosity of the copolymers did not depend on the molecular weight, but on the chemical structure. The complex viscosity of the copolymers containing 3 mol % of DEG, BD, and 5 mol % of BD was lower than that of PEN, and the mechanical properties were similar with the value of PEN. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2900–2905, 1999     

铝表面电化学陶瓷成膜技术及其研究进展

介绍了铝及其合金表面采用电化学陶瓷成膜技术制备无机非金属膜的工艺。采用扫描电镜、电子能谱、X射线衍射和X射线光电子能谱等方法分析DECF膜层的组成成分、结构、表面形貌。探讨了膜层性能的影响因素和成膜机理，同时对比了EDCF技术与常规阳极氧化技术。EDCF技术具有创新性，是一项有很好应用前景的铝表面处理技术。