玉米生物基化工醇高沸点组分分离研究

生物基化工醇生产过程中产生的高沸点组分GC-MS分析。分离出22个峰,鉴定14个组分,主要为长链二元醇(38.43%)和环状二元醇(57.43%)。探讨了减压蒸馏和分子蒸馏分离高沸点组分。结果表明,减压蒸馏和分子蒸馏可实现生物化工醇高沸点组分分段分离。     

采用超临界CO_2萃取-分子蒸馏技术对云产玫瑰油的提取分离及GC-TOFMS分析

采用超临界CO_2萃取技术提取云产玫瑰油,然后用分子蒸馏技术对所得的萃取物进行精制分离,得到高品质的玫瑰油。然后用气相色谱-飞行时间质谱(GC-TOFMS)分析鉴定超临界萃取-分子蒸馏技术提取的玫瑰油成分,用峰面积归一法计算各个组分相对含量。从超临界CO_2萃取和分子蒸馏物中分别分离鉴定出51种和44种成分。主要香气成分及其相对质量分数为香茅醇(34.34%)、橙花醇(16.68%)、香叶醇(2.32%)和芳樟醇(3.14%)。通过超临界CO_2萃取-分子蒸馏技术对云产玫瑰油进行提取分离及成分研究,为国产玫瑰资源的进一步开发利用提供了依据。     

分子蒸馏分离超临界CO2萃取的米槁精油及其成分分析

为了更好地研究米槁精油的化学成分,用分子蒸馏分离超临界CO2流体萃取的米槁精油,通过改变蒸馏温度和压力,共得到12个馏分。用GC-MS分析其化学成分,共鉴定出98个化学成分,在其馏分中首次检测出朱栾倍半萜、榧叶醇等44个新组分。与传统的蒸馏和柱层析分离方法相比,分子蒸馏技术具有分离快、不破坏其化学组成、没有组分流失的优点,是分离米槁精油组分的有效方法。该文报道工作的新颖性,已为贵州省科学技术情报研究所2007年4月30日出具的第200752001178号《科技查新报告》所证实。     

分子蒸馏分离三辛胺与十氢萘工艺研究

有机胺萃取剂三辛胺和稀释剂十氢萘的高效低成本分离是含钙废液与CO2反应-萃取-结晶耦合技术工程化应用的重要环节.文中选用分子蒸馏技术分离热解工段热解液三辛胺与十氢萘的混合物,考察了刮膜器转速、蒸馏温度、系统压力和进料流量等因素对重组分残余十氢萘质量分数的影响,并通过正交试验对单因素条件进行优化,获得最优工艺条件为蒸馏温...     

玉米化工醇副产物树脂C中有用组分的分离研究

提出了一种玉米化工醇副产物树脂C中有用组分的分离新工艺,经二、三元混合醇分离、山梨醇分离、有机酸分离等步骤得到有用组分。确定二、三元混合醇分离优化工艺为:蒸馏温度290℃、蒸馏时间40 min,二、三元混合醇收率为29.46%;山梨醇分离优化工艺为:加水量250 mL、蒸馏时间50 min,山梨醇收率为14.30%;有机酸分离优化工艺为:1 mol.L-1盐酸加量250 mL、蒸馏时间40 min,甲酸和乙酸的收率分别为3.82%和9.28%。树脂C中有效组分的总收率为56.86%。     

生物油组分分离与化学品提取的研究进展

生物质在高温无氧条件下热解可以生成富含高附加值化学品和燃油成分的生物油。有效分离技术和高效提取手段的发展是生物油质量提升的关键。基于此,本文在介绍生物油性质与生物质快速热解工艺的同时,对目前国内外的生物油分离技术如蒸馏、液-液萃取、柱色谱、超临界萃取、膜分离等进行了较为详细的分析和评述。常规蒸馏和溶剂萃取等技术,工艺成熟、操作简单,但存在生物油的热敏性差、萃取剂回收难度大和污染严重等问题;分子蒸馏技术分离过程安全环保,但工艺复杂,设备成本高;超临界萃取和膜分离等技术安全环保,技术成熟,具有较大的潜力。文章还综述了目前生物油中具有高附加值的组分和单一化学品的分离提取研究进展,为生物油的有效分离和高效利用提供了理论参考,也为未来生物油分离技术的发展提供了研发方向。     

生物油的性质及其分离研究进展

综述了蒸馏、萃取、层析、膜分离、超临界萃取等技术在生物油分离方面的研究进展情况。介绍了常减压蒸馏主要用于生物油的粗分,且受到生物油热敏性的限制;分子蒸馏在生物油的分离方面具有一定的优势。溶剂萃取存在着萃取剂与被萃组分分离困难的缺点,且萃取选择性较差;选择或设计具有特定结构的化合物与生物油中的某种或某些组分作用,进而将其萃取分离是未来的一个研究方向;色谱分离可以高效地将生物油的主要成分分离出来,但吸附量小,适合于生物油成分的定量分析和高附加值化合物的提取与纯化。超临界CO2萃取可有效地克服生物油的热敏性,无需反萃,具有潜在的开发优势。开展生物油分离的基础性研究和多种技术的集成化是未来的重要研究方向。     

生物油分离技术的研究进展

生物质是唯一可储存的、能实现CO2零排放的清洁可再生资源。通过快速热解将其转化为液态生物油是生物质利用的一种高效途径。生物油通过精制改性可制备生物柴油,而从中分离出高价值化学品是实现生物油快速商业化的方法。生物油的分离具有重要意义,本文综述了近年来用蒸馏、萃取、柱层析、分子蒸馏和超临界萃取方法分离生物油的研究进展及生物油中不同组分的化学用途。总结了生物油分离技术存在的主要问题,并展望了生物油分离研究的发展方向。     

玉米化工醇重组分中有机羧酸络合萃取过程

采用络合萃取技术,以磷酸三丁酯(TBP)为络合剂进行玉米化工醇重组分络合萃取有机羧酸过程研究。探讨了萃取剂浓度、稀释剂的选择、萃取时间、油水比(O/W)、釜残液酸度、萃取级数对萃取平衡常数(D)的影响。结果表明,经四级萃取后,玉米化工醇重组分中有机酸萃取率可达90.7%。     

模拟生物油分子蒸馏的响应面法工况优化

分子蒸馏是一种高效的生物油分离技术。本文应用刮膜式分子蒸馏装置,对模拟生物油在不同蒸馏温度、蒸馏压力和进料速率下的分离特性进行了研究,考察不同因素对族类化合物蒸出特性的影响。随后采用响应面分析法对模拟生物油分子蒸馏进行了计算机模拟,考察多种因素对分子蒸馏的交叉影响。通过ANOVA分析,模型的F值为21.25,表明模型是显著的。并以目标物酸醛酮在馏分中的质量分数为响应值得到最佳工况：蒸馏温度69.83℃,蒸馏压力1498.31Pa,进料速率5.54mL/min,此时轻质馏分中酸醛酮的质量分数为39.12%。最后在此工况下开展了模拟生物油的验证实验,结果显示馏分中目标物的质量分数为38.96%,与响应面模型吻合良好。模拟生物油经过分子蒸馏后酸醛酮的质量分数由28.50%提升至38.96%,同时酚类的质量分数由37.50%降低到25.14%。     

Polyether polyols as GPC calibration standards for determination of molecular weight distribution of polyether polyols

Average molecular weights (M_n, M_w and M_p) are important characteristics of oligomers and polymers, and therefore there is a need to have a precise and reliable determination method. A gel permeation chromatography (GPC) coupled with a single refractive index detector was used to determine the molecular weight distributions of commercial polyether polyols calibrated against a series of polyether polyols with known molecular weights and low polydispersity. Results of these GPC analyses were compared to the ones calibrated against the commercially available polystyrene (PS) standards. The number‐average molecular weights (M_n) obtained with GPC using polyether polyols calibration were closer to the theoretical values than the M_n obtained using PS as calibration standards. Hence, these GPC analyses using polyether polyols as calibration standards can provide reliable determination of molecular weight distribution of polyether polyols and can be potentially applied to natural oil‐based polyols, including palm oil‐based polyols. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42698.     

Seed oil based polyester polyols for coatings

The hydroformylation of seed oil based fatty acid methyl esters leads to aldehyde intermediates that can be hydrogenated to give novel seed oil based monomers. In this study, the seed oil based monomers were polymerized with low molecular weight diols to produce novel aliphatic polyester polyols with very low viscosities. The seed oil polyester polyols provide environmentally friendly (green) coating formulations with low volatile organic compound emissions which lead to coatings with superior physical properties, such as exceptional hydrolytic resistance and flexibility. From these polyester polyols, waterborne polyurethane dispersions were also developed with excellent stability resulting in coatings with superior physical properties (i.e., good toughness and abrasion resistance), and exceptional hydrolytic and acid resistance.     

Polyester polyols and polyurethanes from ricinoleic acid

Triols of molecular weights (MWs) 1000–4000, suitable for flexible foams, were prepared by transesterification of methyl esters of ricinoleic acid with trimethylol propane. These polyols were noncrystallizing, relatively low‐viscosity liquids. They were reacted with diphenylmethane diisocyanate (MDI) to obtain elastomers having glass transition temperatures below ?60°C. Polymer networks from high‐MW polyols exhibited relatively high sol fractions suggesting that some cyclization occurred during polyol preparation. The low Shore hardness, relatively low strength and modest elongation of the elastomers were attributed to the specific structure of polyricinoleic chains and the presence of dangling chains, serving as plasticizers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

The physical and mechanical properties of polyurethanes from oleic acid polyols

Three different polyester polyols, with various oleic acid content, were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40, and Alk65, in which 28, 40, and 65 represent the percentage of oleic acid of the polyol formulations. These polyester polyols were reacted with aromatic diisocyanate [toluene diisocyanate (TDI)] to form PUR coatings. The acid value, hydroxyl value, molecular weight, and viscosity of the polyols have been determined. The reaction between the polyols and TDI was studied by Fourier Transform Infrared spectroscopy and X‐ray diffraction (XRD). The effects of varying NCO/OH ratio and oleic acid content of polyols on physical and mechanical properties of PUR films were studied. XRD results indicate that the samples are amorphous. PURs, made with Alk28, have the best mechanical properties followed by Alk40 and Alk65. The mechanical properties of the samples have increased as the NCO/OH ratio was increased from 1.2 to 1.6. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Use of gas-liquid chromatography in the analysis of rigid polyurethane foam polyols

Detailed characterization of the low molecular weight polyols used as intermediates in rigid polyurethane foam production has not been feasible to date. Gas-liquid chromatography of the trimethylsilyl ether derivatives of the polyols now offers a more complete picture of polyol composition, particularly with regard to the molecular weight distribution. The data may be interpreted on a semiquantitative basis. The study of processing variables in polyol manufacture, detection of impurities and analysis of unknown polyols or those based on mixed initiators may all be facilitated by use of this GLC technique.     

Moisture-cured polyurethane based on polyester and polycarbonate polyols

Moisture-cured polyurethanes were prepared by reacting toluene diisocyanate and sebacic acid-based hydroxy esters such as ethylene glycol sebacate, propylene glycol sebacate, diethylene glycol sebacate, and polyester polyols such as poly(ethylene glycol sebacate), poly(propylene glycol sebacate), poly(diethylene glycol sebacate), and poly(butane diol sebacate). The effect of molecular weight of the esters on film properties and the catalytic effect of 3–5% triethylamine, triethanolamine, and 2-diethylaminoethanol on curing of such films were investigated. Polyurethanes were also prepared using a blend of poly(butane diol carbonate) polyol with polyester polyols. Best polyurethane compositions were obtained when sebacic acid-based polyester polyols were blended with poly(butane diol carbonate) polyol in the ratio of 3:2. These polyurethanes show good tensile strength (120–215 kg/cm²) and elongation (340–460%) properties, having high melting points (247–268°C) and good resistance to solvents and chemicals. Moreover, they are colorless and transparent.     

Hyperbranched polyols from hydroformylated methyl soyate

Hydroformylation of methyl soyate produces a mixture of fatty acid methyl esters with zero, one, two, and three hydroxyl groups, the major component being with two hydoxyls (around 50%). Polymerization of methyl esters of hydroxy fatty acids gives a hyperbranched product with a different content of hydroxyl groups depending on the degree of conversion. Molecular weights can be controlled by controlling the degree of conversion but also using monofunctional components. A range of hyperbranched polyols with acceptable viscosities and functionalities, suitable for flexible applications, was obtained by stopping the reaction at varying degrees of conversion. Monte-Carlo simulation of the polymerization of hydroxylated methyl soyate gave molecular weights and polydispersity which were compared with experimental values. Although hydroxylated methyl soyate contains considerable amounts of mono- and difunctional fatty acids, the system produces a physical gel at the highest conversions. This is due to very high molecular weights and was confirmed by experiments and the simulation. The simulation unexpectedly gave lower molecular weights but wider distribution than the experiments. This discrepancy was explained by the combination of experimental difficulties and possible side reactions leading to higher molecular weights. Functionality of polyols determined from gel points at critical NCO/OH ratios was reasonably close to predictions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

生物质多元醇选择性催化氢解制小分子二元醇研究进展

乙二醇、1,2-/1,3-丙二醇等小分子二元醇在精细和有机化工、生物医药等领域应用广泛。与石化路径相比,以可再生的生物质多元醇（丙三醇、山梨醇/木糖醇）为原料选择性催化氢解制取上述小分子二元醇具有过程简单、绿色高效等显著优势,已成为生物质催化转化的研究热点。本文综述了典型生物质多元醇山梨醇/木糖醇和丙三醇选择性催化氢解为乙二醇、1,2-/1,3-丙二醇等小分子二元醇,重点阐述了丙三醇选择性氢解制1,2-丙二醇、1,3-丙二醇和山梨醇/木糖醇选择性氢解制小分子二元醇的催化剂体系和反应机理,并对该领域的发展前景作了展望,提出开发高效稳定的催化剂体系和工艺是未来的研究重点。     

Self-emulsifiable soybean oil phosphate ester polyols for low-VOC corrosion resistant coatings

A series of soybean oil phosphate ester polyols (SOPEP) was prepared by reaction of fully epoxidized soybean oil with phosphoric acid and simultanoeous hydrolysis in the presence of a polar solvent. The polyols were characterized by determination of acid value, oxirane number, hydroxyl value, molecular weight (GPC), and FTIR spectra. These polyols with varying amounts of acid phosphate groups could be self-emulsified to form aqueous dispersions after neutralization with organic base. These aqueous dispersion showed varying degrees of stability and their appearance ranged from opaque dispersions to translucent to clear solutions. Waterborne coating compositions were prepared using these aqueous dispersions as principal components and their thermally cured film properties were studied. it was found that by careful selection and formulation, SOPEPs can be successfully used for low-VOC waterborne coating formulations. SOPEPs with 3.5% phosphate ester content showed visibly superior corrosion resistance properties.