Epoxidised soybean oil

Epoxidised soybean oil (ESBO) Epoxidised linseed oil (ELO) Primary use as a secondary heat stabiliser but also impart flexibility. Compatible only at relatively low addition levels. General use... 

Epoxidised soybean oil or epoxidised sunflower oil are commercial products obtained by the epoxidation of vegetable oils with peroxyacetic or peroxiformic acid (generated... 

The hydrolysis of epoxidised soybean oil was investigated in the presence of acidic catalysts (sulfuric acid, p-toluene sulfonic acid, phosphoric acid). The objective was to obtain a maximum hydroxyl number with a minimum hydrolysis of the ester bonds [58]. The idealised reaction for epoxidised soybean oil hydrolysis is presented in reaction 17.20. 

Theoretical hydroxyl numbers of the polyols resulting from epoxidised soybean oil hydrolysis are in the range 440-450 mg KOH/g. If the epoxidised soybean oil has 4 epoxy groups/mol, the resulting functionality of polyol obtained by hydrolysis is 8 hydroxyl groups/mol. 

Unfortunately, the resulting hydroxyl number is much lower, around 200-250 mg KOH/g. The explanation of these lower hydroxyl numbers is the reaction between the hydroxyl groups formed during hydrolysis reaction with the epoxy groups of unreacted epoxidised soybean oil (reaction 17.21). The intermolecular reactions formed dimers, trimers and superior oligomers, of higher functionality (f > 8 OH groups/mol). 

By the reaction of alcohols (in excess) with epoxidised vegetable oils in the presence of acids as catalysts - liquid polyols are formed (reaction 17.22). For example by the alcoholysis of epoxidised soybean oil with methanol, at the reflux temperature of methanol (the boiling point of methanol is 64.7 °C), in the presence of an acidic catalyst (H2S04, p-toluene sulfonic acid, HBF4 [31, 34, 44, 45], solid acidic clays [39], supported acidic catalysts), liquid soybean oil based polyols are obtained, with an hydroxyl number of around 170-173 mg KOH/g, a functionality of about 3-4 OH groups/mol and a viscosity of around 4,000-7,000 mPa-s at 25 °C. After the neutralisation of the acidic catalyst or by the filtration of solid acid catalysts, the methanol is distilled under vacuum and recycled back into the process. 

Thus, by reaction of epoxidised soybean oil with a mixture of methanol - water in the presence of an acidic catalyst, polyols are obtained, with an hydroxyl number in the range 200-210 mg KOH/g and a viscosity between 10,000-16,000 mPa-s at 25 °C [59, 61]. 

Vegetable oil-based polyols obtained by epoxidation are treated with diisocyanates in the presence of a suitable chain extender and catalyst to obtain polyurethanes (Fig. 6.5). Polyurethanes have been prepared from olive, peanut, canola, corn, soybean, safflower and sunflower oil by the conventional epoxidation process, followed by treatment of the polyols of the epoxies with diphenylmethane diisocyanate. Polyurethane resins may also be obtained by the treatment of soybean polyols (which are obtained by methanolysis of epoxidised soybean oil with isocyanates at a temperature of 50°C) or from epoxidised linseed oil with TDI using xylene as the solvent. 

Acrylated epoxidised soybean oil (AESO) (Rg. 7.6) is synthesised from the reaction of acrylic acid with epoxidised triglycerides. Similarly malein-ated hydroxylated soybean oil (Rg. 7.6) can be obtained by the reaction of epoxidised oil with maleic anhydride. 

Epoxidised triglycerides can be found in natural oils, such as vernonia plant oil, or they may be synthesised from more common unsaturated oils, such as soybean or hnseed oil, by a standard epoxidation reaction. The reaction of acrylic acid with epoxidised soybean oil (ESO) occurs through a standard substitution reaction. Although the reaction of ESO with acrylic acid is partially acid catalysed by the acrylic acid itself, tertiary amines such as A,A-dimethylanihne, triethylamine and 1, 4-diazobicyclo[2.2.2]-octane are commonly used as the catalysts. 

Monomethyl maleic ester of epoxidised soybean oil (MESO) is prepared by the reaction of epoxidised oil with monomethyl maleate with AMC-2 catalyst. (AMC-2 is a mixture of 50% trivalent organic chromium complexes and 50% phthalate esters). This MESO is photo-polymerised with ultraviolet light and free radically homopolymerised and copolymerised with styrene, vinyl acetate and methylmethacrylate. MESO may also be reacted with maleic anhydride at the newly formed hydroxyl groups to give maleinised MESO. Thus a large number of resinous systems may be made from the epoxidised oil. 

Anhydride cured combined epoxy of epoxidised linseed oil or epoxidised soybean oil with bisphenol-A-based diglycedyl ether epoxy, gives a high elastic modulus, high glass transition temperature, a high Izod impact... 

A new hybrid composite was produced by a combination of synthetic and natural fibres with the same AESO matrix, which offered the low cost of natural fibre with the high strength of synthetic fibre. The resultant properties may vary, depending on the composition of the fibre type and follow a weight fraction rule. It has been observed from SEM micrographs that hemp acrylated epoxidised soybean oil (ESO) composite shows fracture surfaces with a larger number of pull outs than the flax-based composites. 

Epoxidised soybean oil-based natural composite exhibits strong viscoelastic solid properties similar to those of synthetic rubbers and can therefore replace them in many applications. Composite materials obtained by the vinylation of epoxidised soybean oil-based resin and natural fibre by styrene or acrylic acid, are used in the roofs, floors and walls of houses and low-rise commercial buildings. 

Acrylated epoxidised soybean oil (AESO)/impure MWCNT (MWCNT and carbon soot) nanocomposite exhibits improved mechanical properties with the tensile modulus increased by 30% at 0.28 wt% CNT loading. However higher multi-walled carbon nanotube loadings resulted in significant aggregation during polymerisation. AESO is therefore believed to act as a solubilising surfactant in this system. ... 

MESO monomethyl maleic ester of epoxidised soybean oil... 

Latent initiators that are activated photochemically or by heating, such as benzylpyrazinium salts, enable controlled polymerisations. In fact, the activity of pyrazinium salts can be controlled by electronic modifications of benzyl and pyrazine groups [5]. Epoxidised soybean and castor oils have been polymerised by cationic means in the presence of the latent initiator N-benzylpyrazininm hexaflnoroantimonate [6]. Cationic resins prepared from epoxidised castor oil display higher glass transition temperature (Tg) values and lower coefficients of thermal expansion than counterparts prepared from epoxidised soybean oil (ESO) because of increased intermolecnlar interactions in the former materials when compared with the latter polymer [6]. 

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