2,2',2'-Terpyridine-Catalyzed Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide under Solvent-Free Conditions

An efficient coupling reaction of epoxides with CO₂ affording cyclic carbonates with the use of 2,2'',2''''-terpyridine as catalyst under solvent-free conditions has been developed.     

Recent Development of Biobased Epoxy Resins: A Review

Currently, the utilization of renewable resources for sustainable technology is in the renown of consumer as well as industrial attention, especially, chemical industries because of their availability, low cost, credentials toward environmental issues such as lower ecotoxicity, CO₂ footprints, and inbuilt biodegradability. These natural properties are being taken advantage of in research and development, with vegetable oil-, furan-, lignin-, rosin-,vanillin-, and itaconic acid-derived biobased epoxy resin being used in various applications including paints, coatings, adhesives, and biomedicine. The present review mainly focuses on the utilization of natural resources for the synthesis of biobased epoxy and its curing agents.     

Synthesis and Characterization of Polyethylene Glycol Diesters from Estolides Containing Epoxides and Diols

Estolides from oleic acid, 12-hydroxystearic acid, and methyl ricinoleate were synthesized and converted to polyethylene glycol (PEG) diesters. Oleic estolide was synthesized from oleic acid as a homo-oligomeric material using perchloric acid in 68.8% yield and an estolide number (EN) value of 1.29. Estolides from 12-hydroxystearic acid were homo-oligomers made by heating under vacuum at 150 °C for 24 hours to give a quantitative yield of estolide with an EN value of 2.55. Oleic acid-based estolides and 12-hydroxystearic acid-based estolide were esterified with PEG-200 diol to form PEG 200 diesters. Ricinoleate estolides was capped with lauric acid or 12-hydroxystearic estolide by reacting methyl ricinoleate with the corresponding fatty acids at 150 °C using tin(II) octoate as a catalyst. The corresponding estolides were transesterified with PEG-200 diol to form the diesters. The residual olefin of ricinoleate was then epoxidized and underwent ring opening hydrolysis to form the corresponding diol. NMR spectroscopy (¹H, ¹³C, distortionless enhancement by polarization transfer, heteronuclear single quantum correlation, heteronuclear multiple bond correlation, and correlated spectroscopy) was used to characterize the products.     

环氧基多孔磁性复合微球的制备及性质

以聚醚为致孔剂,通过悬浮聚合法制备了表面带有环氧基的多孔磁性复合微球。用红外光谱(FTIR)、扫描电子显微镜(SEM)、磁强计(VSM)、压汞法等对其进行了表征,考察了分散剂质量分数对多孔磁性微球性能的影响。结果表明,该微球粒径为35～50μm,表面有不规则孔道,w(Fe3O4)≈15.8%,饱和磁化强度8.98 emu/g。水相中w(PVA)由1.5%升至3%时,微球平均粒径由130μm变为40μm,而平均孔径亦由144 nm降为39 nm。     

Salen-Al/季铵盐催化体系催化生物基原料制备大豆油环碳酸酯研究

合成制备了4种不同席夫碱金属配合物(Salen-Al),利用红外(IR)、紫外(UV)、核磁(1HNMR)、元素分析(EA)、离子含量(ICP)等对其表征。筛选催化活性较高的Salen-Al与季铵盐进行复配形成二元催化体系,催化环氧大豆油和CO2合成制备大豆油环碳酸酯。利用红外,核磁对产物进行表征分析。同时考察了二元催化体系下环氧大豆油与CO2合成大豆油环碳酸酯的反应温度、压力、复配比等因素。研究表明,在温度为120℃、压力2 MPa条件下,Salen-Al与季铵盐摩尔比1∶1时有较高的催化效率,反应8 h转化率高达76.8%,对比单组份催化时有明显的提高。     

Synthesis and Physical Properties of Tallow-Oleic Estolide 2-Ethylhexyl Esters

Tallow-oleic estolide 2-ethylhexyl (2-EH) esters were synthesized in a perchloric acid catalyzed one-pot process from industrial 90% oleic and tallow fatty acids at various ratios, while varying the ratio of tallow and oleic fatty acids, with the esterification process incorporated into an in situ second step to provide a functional fluid. Their viscosities ranged 57–80 cSt at 40 °C and 10.8–14.0 cSt at 100 °C with viscosity index (VI) 169–185. The 100% tallow estolide 2-EH ester had modest low-temperature properties (pour point = −15 °C and cloud point = −14 °C), while the 50:50 mixture of oleic and tallow fatty acids produced an estolide that had better low-temperature properties (pour point = −21 °C and cloud point = −21 °C) without a large negative effect on the oxidative stability. The oxidative stability increased as the amount of saturation increased (rotating pressurized vessel oxidation test (RPVOT) × 165–274 min). The tallow-oleic estolide 2-EH esters have shown remarkably low evaporative losses of only 1% loss compared to a 15–17% loss for commercial materials of similar viscosity grade. Along with expected good biodegradability, these tallow-oleic estolide 2-EH esters had acceptable properties that should provide a specialty niche. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Regioselective Organocatalytic Formation of Carbamates from Substituted Cyclic Carbonates

A highly regioselective catalytic approach has been developed towards carbamates derived from cyclic organic carbonates by reaction of the latter with amine reagents under organocatalytic control. For various combinations of carbonate and amine substrates, an organocatalyst (TBD: 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene) was used to increase the reaction kinetics while exerting excellent regioselective control. The current method is the first general approach towards the control over the regioselectivity of this reaction using a wide variety of easily accessed substituted organic carbonates.

     

季膦盐离子液体／卤化锌催化CO2环加成反应

制备了一种由氯化锌和三己基十四烷基季膦盐离子液体组成的Lewis酸／碱复合催化体系,将其用于CO2与环氧烷烃的环加成反应,表现出高催化活性。系统地考察了反应温度、反应压力、反应时间及催化剂组成的影响,结果表明,以[（C6H13）3P（C14H29）]Br／ZnCl2（物质的量之比为2：1）为催化剂,在CO2压力为2MPa,反应温度为100℃,反应15rain条件下,碳酸丙烯酯收率达到95％。研究表明该催化体系也适用于CO2与其他环氧化物的环加成反应。最后提出了该催化体系的反应机理。     

Synthesis and Properties of New Cleavable Cationic Surfactants Containing Carbonate Groups

A novel series of cleavable alkyltrimethylammonium surfactants with different hydrocarbon chain lengths (C8–16) were synthesized. A carbonate break site inserted between the polar head and the hydrocarbon chain makes these compounds hydrolyzable. The reagents used are renewable, (bio)degradable, or reusable. The hydrolysis of these cleavable surfactants will lead to the generation of fatty alcohols and choline, which is an essential biological nutrient. The surface activities in aqueous solution of the synthesized carbonates fulfill the requirement of being good surfactants. In addition, the cleavable compounds containing n-decyl and n-dodecyl chains showed similar or higher antimicrobial activities when compared to a non-cleavable analog.     

双酚-S酯液晶环氧树脂的的合成与表征

以乙二醇单烯丙基醚（AHEE）、对羟基苯甲酸乙酯和双酚-S（BPS）为原料,经酯化和氧化的方法合成了4,4’-二[4-（2,3-环氧丙氧基乙氧基）]苯甲酸双酚-S酯（p—BPSDEB）环氧液晶化合物,用FTIRR、^1H NMR、DSC和偏光显微镜对液晶化合物进行了表征。证明该化合物为近晶型液晶,其熔点是106℃。     

端环碳酸酯基聚醚的合成

采用端环氧基聚醚与二氧化碳为原料,在高温、高压、催化剂的条件下,将环氧基转化为五元环碳酸酯基。讨论了催化剂类型、温度、压力对反应转化率的影响,并通过红外光谱、核磁共振氢谱等方法对端环碳酸酯基聚醚进行结构表征。结果表明,当采用十六烷基三甲基溴化铵为催化剂,温度为120℃,体系压力为2.5 MPa时,环氧基的转化率能够达到90%以上。     

超临界二氧化碳萃取器萃取分离香茅油

本文介绍了利用现有１５０Ｌ高压釜（压力２０ＭＰａ）改造的超临界二氧化碳萃取器萃取分离香茅油,探讨了压力、温度、时间对萃取分离效果的影响。结果表明,采用超临界二氧化碳萃取器萃取分离香茅油时应选择一个适宜的压力、温度和萃取时间,产品的色、香味、纯度均优于常规的减压蒸馏法。     

硅胶负载酸性离子液体催化CO_2环加成反应

制备了4种硅胶负载酸性离子液体,将其作为催化剂用于环氧烷烃和CO2的环加成反应,表现出高催化活性。系统地考察了不同负载离子液体的催化性能、反应压力、反应温度、反应时间和催化剂用量的影响,结果表明,硅胶负载的酸性离子液体在该环加成反应中具有良好的催化活性,环氧丙烷转化率均大于95%。在以[Smim]HSO4(0.5 g)作为催化剂时,碳酸丙烯酯的选择性为最大值90.6%。使用该催化剂0.5 g,以2.5 m L环氧丙烷(PO)作为反应物,在CO2压力1 MPa,反应温度140℃,反应5 h的条件下,环氧丙烷的转化率为96.3%。循环使用6次后,活性没有明显降低。提出了可能的反应机理。     

大豆油与CO2合成五元环状碳酸酯

采用天然可再生资源大豆油的环氧化产物(ESBO)和CO2为原料,以碘化钠和N,N-二甲基甲酰胺为催化体系,通过环加成反应合成了五元环状碳酸酯(CSBO)。考察了不同碱金属卤化物及不同溶剂的催化效果,证明碱金属卤化物碘化钠和N,N-二甲基甲酰胺为一种高效催化体系。进一步测试温度对反应的影响,证明合适的反应温度为120℃。用红外光谱,核磁共振氢谱,黏度计,凝胶色谱,热分析对产物进行了结构分析,表明以碘化钠和N,N-二甲基甲酰胺为催化剂,温度120℃,CO2压力1MPa,反应时间20h的条件下,环氧大豆油的转化率可达90.4%。     

含苯环侧基三元共聚PI的合成及其表征

以4,4’-二胺基二苯醚(ODA)、2,2’-双[3-苯基-4(4-氨基苯氧基)苯基]丙烷(BPAPOPP)和均苯四甲酸酐(PMDA)为单体,采用溶液共缩聚方法合成了一系列共聚聚酰亚胺(PI)薄膜;采用傅里叶红外光谱仪(FTIR)、差示扫描量热仪(DSC)等分析了PI薄膜的结构和性能。结果表明:随着高聚物中柔性体系含量的增加,PI薄膜的热学性能和力学性能都有一定程度降低;但其加工性能得到了改善。     

On the application of supercritical fluid extraction to the deacidification of olive oils

A recent suggestion on the applicability of supercritical fluid extraction to the deacidification of olive oils of high acid content was based on solubility data in clear disagreement with the results of other authors. In this work, we measured the solubilities of substances chosen for their importance in that extraction process, namely pure glycerol trioleate, the most abundant triglyceride in olive oil, and of a husk oil with a high acid content. Our results agree well with some of the previous reports on this subject. These seem to be a trustworthy data base, but more results are needed for a definite conclusion about the technical feasibility of the process.     

Synthesis of silver-polystyrene nanocomposite particles using water in supercritical carbon dioxide medium and its antimicrobial activity

A novel method based on ex situ dispersion of silver nanoparticles within the monomers and subsequent emulsion polymerization using water-in-sc-CO₂ medium is introduced in this paper. Silver nanoparticles were synthesized by chemical reduction of silver nitrate using sodium borohydrate as a reducing agent and polydimethylsiloxane (PDMS) as a stabilizer in the water-in-sc-CO₂ medium. The stable dispersion of silver nanoparticles was added slowly during the polymerization of styrene in the water-in-sc-CO₂ maintaining the temperature at 70 °C and pressure at 20.68 MPa, respectively. The silver nanoparticles encapsulated within polymer particles were characterized by UV-visible spectroscopy, XRD, TGA, SEM and TEM. The silver/polystyrene nanocomposite particles exhibited antimicrobial activity against a number of bacteria. The current work represents a simple, reproducible and universal way to prepare a variety of metal-polymer nanocomposite particles.     

葵花籽油基多元醇的合成与表征

以葵花籽油为原料,在冰醋酸和过氧化氢的共同作用下进行环氧化,制备葵花籽油基环氧化产物(SOEP);再以氢氧化锂为催化剂与二乙醇胺发生环氧开环反应,制备得到葵花籽油基多元醇(SOPOL)。探讨了反应温度和时间、冰醋酸/过氧化氢摩尔比对SOEP和SOPOL性能的影响,并采用核磁共振表征了SOEP和产物SOPOL的结构。结果表明,制备SOEP较为理想的反应温度为65℃,反应时间为10 h,葵花籽油(以双键计)、冰醋酸与过氧化氢的摩尔比为1∶2∶4;在135℃进行环氧基开环反应制备的SOPOL羟值可达到176 mgKOH/g,平均官能度为4.2。该SOPOL可替代传统石油基多元醇合成生物基聚氨酯树脂。     

碱性树脂催化合成生物质五元环状碳酸酯

生物质材料环氧大豆油和CO2在碱性树脂D201的催化下,通过环加成反应生成五元环状碳酸酯。近一步对D201树脂进行改造和改性,得到系列新型碱性树脂催化剂,考察了温度、时间、催化剂种类等因素对反应的影响。结果表明,制备的碱性树脂催化剂的催化活性均高于D201树脂,其中以碘离子改进型碱性树脂催化剂的催化活性最高,在反应温度为120℃、反应时间为12 h的条件下,可使环氧大豆油的转化率达到90%以上。