Oxirane Cleavage Kinetics of Epoxidized Soybean Oil by Water and UV‐Polymerized Resin Adhesion Properties

Di‐hydroxylated soybean oil (DSO), a biobased polyol synthesized from epoxidized soybean oil (ESO) could be used to formulate resins for adhesives; however, current DSO synthesis requires harsh reaction conditions that significantly increase both cost and waste generation. In this paper, we investigate the kinetics of oxirane cleavage in ESO to DSO by water and elucidate the role of different process parameters in the reaction rate and optimization of reaction conditions. Our kinetic study showed that ESO oxirane cleavage was a first‐order reaction and that the ESO oxirane cleavage rate was greatly influenced by tetrahydrofuran (THF)/ESO ratio, H₂O/ESO ratio, catalyst content, and temperature. Optimized reaction parameters were THF/ESO of 0.5, H₂O/ESO of 0.25, catalyst content of 1.5 %, and reaction time of 3 h at 25 °C. DSO with hydroxyl value of 242 mg KOH/g was obtained under these conditions. We also characterized the structure, thermal properties, adhesion performance, and viscoelasticity of UV‐polymerized resins based on this DSO. The resin tape exhibited peel adhesion strength of 3.6 N/in., which is comparable to some commercial tapes measured under similar conditions.     

Ring Opening of Epoxidized Soybean Oil with Compounds Containing Two Different Functional Groups

Epoxidized vegetable oils are desirable chemicals due to their eco‐friendly characteristics and their being a major source of many green products. Ring opening is one of the ways to convert these epoxidized oils to some new intermediates. The use of mono‐functional amines, alcohols, acid anhydrides and thioethers for epoxy ring opening has been reported in the literature. In this study, thioglycolic acid (TGA) bearing thiol and carboxylic acid as two different functional groups and methyl ester of thioglycolic acid (TGAME) were used. Currently, there is no reported literature describing epoxy ring opening using chemicals bearing two different functional groups simultaneously. In this way, two new polyols were synthesized, one with TGA (polyol 1) and one with TGAME (polyol 2). FTIR and ¹H‐ and ¹³C‐NMR spectroscopy confirmed that the ring was opened by the carboxylic acid group of TGA, and the thiol group was not involved in the ring opening whereas the ring was opened by the thiol group in the case of TGAME.     

Carbonation of Epoxidized Soybean Oil Improved by the Addition of Water

Carbonated soybean oil was synthesized from epoxidized soybean oil and CO₂ at atmospheric pressure and with tetrabutylammonium bromide (TBABr) as catalyst. Kinetic parameters, i.e., rate constants, activation energy and pre-exponential factors were determined. The effects of catalyst concentration and water content were studied. The reaction followed first-order kinetics with respect to epoxide at 100–140 °C. A steep increase in conversion (ca. 30 %) was obtained by increasing the amount of catalyst from 3 to 5 %. Further increasing the amount of catalyst to 7 % increased the conversion less than 10 %. The reaction proceeded faster when water was added; reaction times with water were ca. 70 % of the reaction times without water. Titration, FTIR and ¹H-NMR analyses indicated ca. 90 % conversion and ca. 88 % selectivity towards the carbonate after 70 h at 120 °C with 5 % mol TBABr and 1:3 molar ratio of water to epoxide.     

Synthesis and Characterization of the Different Soy-Based Polyols by Ring Opening of Epoxidized Soybean Oil with Methanol, 1,2-Ethanediol and 1,2-Propanediol

Three soy-based polyols intended for application in polyurethanes were prepared by ring opening the epoxy groups in epoxidized soybean oil (ESO, 0.385 mol/100 g epoxy rings) with methanol, 1,2-ethanediol and 1,2-propanediol in the presence of tetrafluoroboric acid catalyst. The effect of the different opening reaction reagents, different low molecular weight alcohols, on the polyols was investigated by spectroscopic, chemical and physical methods. The viscosities, viscous-flow activation energies, molecular weight and melting point of the samples increased in the following order: polyol (3) > polyol (2) > polyol (1) > ESO [polyol (1); polyol (2) and polyol (3) represented the samples synthesized from the same epoxidized soybean oil generated by opening reactions with methanol, 1,2-ethanediol and 1,2-propanediol, respectively]. All the samples were crystalline solids below their melting temperature, displaying multiple melting point peaks. Compared with polyol (1), polyol (2) had a primary hydroxyl group, promoting the reactive activity of the polyol with isocyanates; polyol (3) contained large numbers of hydroxy groups, improving the properties of polyurethanes.     

绿色增塑剂环氧大豆油的合成与表征

用自制的催化剂合成了一种环氧大豆油。通过L16(45)正交试验考察了双氧水用量、催化剂用量、反应时间和反应温度对环氧大豆油环氧值的影响。结果表明:在双氧水用量100份、催化剂用量0.5份(大豆油用量定为100份)、反应温度50℃、反应时间12.5 h的最佳工艺条件下,产品的环氧值为6.58%,碘值为0.83 gI/100g。产品通过红外和核磁共振表征,确定大豆油被环氧化生成环氧大豆油。     

Straightforward Synthesis of Amido Polyols from Epoxidized Soybean Oil for Polyurethane Films

This work reports a straightforward and selective method for the preparation of a polyol that can be used in the manufacture of polyurethane (PU) films. The polyol, from the N-hydroxyalkylamides family, is obtained from the selective amidation and oxirane ring opening of epoxidized soybean oil (ESO) with the amino alcohol N-methylethanolamine (N-MEA). The reaction is carried out under mild conditions and in the absence of solvents and catalysts. Other similar amino alcohols (namely monoethanolamine (ETA), 5-amino-1-pentanol (PEA), and 2-(2-aminoethoxy)ethanol (AEE)) are also used to carried out the amidation of ESO. However, for these amines, the amidation and/or oxirane ring opening of ESO is not complete. Therefore, the N-hydroxyalkylamide obtained from the amidation of ESO with N-MEA is chosen as the polyol for the preparation of PU films. The PU films are obtained from the reaction with a trimer of hexamethylene diisocyanate (Tolonate) and hexamethylene diisocyanate (HDI). Curing proceeds at room temperature, without catalyst. It is shown that the properties of the resulting PU films are dependent on the amount of Tolonate in the formulation.     

Kinetic Study on Oxirane Cleavage of Epoxidized Palm Oil

A ring-opened product (EPO-HOAc) was prepared using epoxidized palm oil (EPO) and acetic acid (HOAc). The kinetics of the oxirane cleavage of EPO were investigated at 50, 60, 70, 80, and 90 °C, respectively, in the presence of HOAc. The rate equation of oxirane cleavage was as follows: r = k[Ep][CH₃COOH]^1.6 ([Ep] is the molar concentration of oxiranes, [CH₃COOH] is the molar concentration of HOAc), and the activation energy of oxirane cleavage was 40.28 kJ mol⁻¹. The structure of EPO-HOAc was confirmed by FT-IR and ¹H NMR. The oxidative stability of EPO-HOAc was better than that of palm oil (PO), and the pour point of EPO-HOAc was lower than that of PO and EPO, which made EPO-HOAc more suitable for biodegradable lubricant materials than PO and EPO.     

无味环氧豆油的合成技术研究

本文阐述无味环氧豆油的合成技术，将精制大豆油，乙酸与其它辅料按配方比例投入反应釜，再慢慢滴加双氧水，使之环氧化反应，待反应完全后，经水洗，中和，脱水等一系列工艺，制成无味环氧豆油成品。这种合成方法，工艺简单，产品质量稳定优良。     

Hydrolysis of Epoxidized Soybean Oil in the Presence of Phosphoric Acid

Ring-opening hydrolysis of epoxidized soybean oil in the presence of phosphoric acid was studied under varying experimental conditions. The influence of type and amount of solvents, phosphoric acid content and water content on the rate of ring-opening reactions and the characteristics of the derived products were studied. The soy-polyols prepared were characterized by determination of hydroxyl content, viscosity measurements, determination of average molecular weight and polydispersity index (GPC). The structural confirmation was done by FT-IR and ¹H-NMR spectroscopy. The study shows that under the reaction conditions employed, a substantial degree of oligomerization due to oxirane-oxirane, and/or oxirane-hydroxyl reaction takes place. It is possible to synthesize soy-polyols having varying hydroxyl content and phosphate-ester functionality by controlling the type and amount of polar solvent and phosphoric acid content.     

不同饱和度环氧大豆油的合成与性质表征

本文用无溶剂法制备环氧大豆油(ESO),研究了反应温度和反应时间对产物环氧值的影响。通过研究环氧大豆油的环氧值与反应时间以及反应温度的关系,选择最佳反应条件。在75℃下,大豆油和过氧乙酸分别反应1、2、3和4 h,分别获得环氧值为0.243、0.317、0.356和0.383 mol/100 g的环氧值不等的环氧大豆油,并研究不同饱和度对环氧大豆油的理化性质的影响。     

大豆油与过氧甲酸的环氧化动力学研究

通过大豆油中的双键与过氧酸发生环氧化反应,合成了环氧大豆油(ESO)。从动力学的角度,对反应过程中的各种影响因素,进行了较详细的研究。得知大豆油与过氧甲酸反应,大豆油的反应级数为1级,过氧甲酸的反应级数为2级,其反应活化能为22.77 kJ/mol。生成的环氧大豆油与体系内的甲酸发生水解开环反应,环氧大豆油的反应级数为0.5级,甲酸的反应级数为1级,该反应活化能为4.91 kJ/mol。通过所得动力学参数设定了无催化剂的环氧大豆油合成工艺,得到了环氧值高达6.85的环氧大豆油。     

Di-Hydroxylated Soybean Oil Polyols with Varied Hydroxyl Values and Their Influence on UV-Curable Pressure-Sensitive Adhesives

Di-hydroxylated soybean oil (DSO) polyols with three different hydroxyl values (OHV) of 160, 240, and 285 mg KOH/g were synthesized from epoxidized soybean oils (ESO) by oxirane cleavage with water catalyzed by perchloric acid. The DSO were clear, viscous liquids at room temperature. The structure and physical properties of DSO were characterized using titration methods, Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography, rheometer, differential scanning calorimetry, and thermogravimetric analysis. The number average molecular weight of DSO160, DSO240, and DSO285 were 1,412, 1,781, and 1,899 g/mol, respectively, indicating that oligomerization occurred during DSO synthesis, which was further confirmed by FTIR. All DSO polyols exhibited non-Newtonian, shear thinning behavior. DSO with higher OHV were more viscous than those with lower OHV. All DSO were thermally stable up to 380 °C. These three DSO were formulated into pressure-sensitive adhesives (PSA) by copolymerizing with ESO using UV curing. The peel adhesion strength of the PSA was significantly affected by the OHV of DSO and DSO content. Maximal PSA adhesion strength of 4.6 N/inch was obtained with DSO285 and a DSO/ESO weight ratio of 0.75.     

钨基催化剂体系下甲醇开环环氧大豆油制备多元醇

以环氧大豆油和甲醇为原料,通过开环加成制备植物油基多元醇。在自制的二氯二氧化钨(WO2Cl2)作催化剂、三氟甲磺酸银(Ag OTf)作助催化剂的条件下,考察了催化剂用量、助催化剂用量、反应时间、温度和醇油物质的量比等对环氧大豆油开环转化率的影响,并对产物的环氧值进行了测试。结果表明,当催化剂用量为3%(以甲醇和环氧大豆油总质量为基准,下同),三氟甲磺酸银用量为4%,反应温度为70℃,反应时间为8 h,醇油物质的量比为28∶1时,环氧大豆油的开环转化率较高,为89.13%。对开环产物进行了FTIR、1HNMR、TG以及流变性分析。通过热重分析得出,多元醇的分解温度(334℃)比环氧大豆油的分解温度(305℃)高。流变性分析得出,随着温度的升高,环氧大豆油和多元醇的黏度逐渐下降。在温度较低时,大豆油多元醇的黏度明显低于环氧大豆油的黏度。     

环氧大豆油增塑剂的应用及其研究进展

环氧大豆油作为常用的辅助增塑剂,拥有价廉、无毒、原料来源广泛等优异的性能,能显著提高材料的柔韧性,起到良好的增塑作用,并能改善材料的缺陷等。同时,通过对环氧基的改性,在植物油基聚合物领域有潜在应用价值,能减少石油化工及煤化工衍生物的依赖,符合绿色环保的要求。根据以上特点,综述其在聚乳酸、紫外光固化涂料、聚氨酯、植物油基泡沫塑料、环氧树脂等聚合物领域的应用及其进展。     

环氧大豆油增塑剂的合成

本合成采用无溶剂一步法环氧化工艺，取消了苯作溶剂，用新型催化剂代替硫酸，在稳定剂上用３０％双氧水合成的环氧大豆油，环氧值达９５％以上。     

新型环氧大豆油丙烯酸酯类UV树脂的合成与表征

分别以丙烯酸羟乙酯（HEA）、季戊四醇三丙烯酸酯PETA、苯酐（PA）和环氧大豆油（ESO）为原料制备了经丙烯酸酯改性的UV大豆油树脂HEAPA-ESO和PETA-ESO;FFIR和^1HNMR分析确认了目标树脂的结构;综合考察了反应时间、催化剂以及温度对PA和ESO环氧基转化率的影响,最佳工艺条件为：对于HEAPA—ESO,以TPP为催化剂、HEA和PA（1．05：1）在100℃下反应2h,再升温至120℃,然后加入环氧大豆后继续反应5h～6h;对于PETAPA—ESO,以TPP为催化剂、PETA和PA（1．08：1）在110℃下反应2h,再降温至100℃,然后加入环氧大豆后继续反应5h～6h。TPP用量为1．4％,阻聚剂对甲氧基酚（MEHQ）用量为0．15％。     

环氧大豆油丙烯酸酯光固化保护材料的合成

以环氧大豆油和丙烯酸为原料合成环氧大豆油丙烯酸酯(ESOA),对催化剂种类和反应温度进行探讨。以四丁基溴化铵为催化剂、100℃时合成的ESOA预聚体为主体树脂、三羟甲基丙烷三丙烯酸酯(TMPTA)为活性稀释剂、184为光引发剂进行涂膜紫外光固化。结果表明,制得的紫外光固化保护膜材料附着力为1级,硬度为5H,收缩率小且具有良好的柔韧性及耐磨性。