Synthesis of Epoxidized Canola Oil Using a Sulfated-SnO₂ Catalyst

Abstract

In the present investigation, a heterogeneous sulfated-SnO2 catalyst was synthesized and used for the epoxidation of unsaturation present in the canola oil. The physicochemical properties were studied to measure the surface and bulk properties of prepared SnO2 and sulfated-SnO2 samples. Process optimization studies were performed for parameters such as catalyst loading, ethylenic unsaturation in canola oil to hydrogen peroxide molar ratio, ethylenic unsaturation in canola oil to acetic acid molar ratio, and temperature. Sulfated-SnO2 demonstrated promising catalytic activity with 100% conversion of unsaturation in canola oil to epoxy canola oil in 6 h at optimum process conditions. Based on the experimental results and kinetic data, a Langmuir–Hinshelwood-Hougen-Watson type mechanism was proposed, and the reaction followed pseudo first order. Calculated energy of activation was 17.75 kcal/mol. The tribological properties of epoxy canola oil such as lubricity property in terms of wear scar length, kinematic viscosities, viscosity index, oxidative induction time, cloud point, and pour point were measured.

Recent advances in bio‐based epoxy resins and bio‐based epoxy curing agents

“…The progress of canola oil as a base chemical for bio‐based epoxy resins is not as far along as that of soybean or linseed oil. Studies over the past couple of years explored the ability to epoxidize canola oil with various catalysts . For example, in a 2014 study aiming to find renewable, bio‐based sources for lubricant applications, Somidi et al ., found sulfated SnO 2 to be the most selective and stable catalyst for epoxidation of canola oil .…”

“…Studies over the past couple of years explored the ability to epoxidize canola oil with various catalysts . For example, in a 2014 study aiming to find renewable, bio‐based sources for lubricant applications, Somidi et al ., found sulfated SnO 2 to be the most selective and stable catalyst for epoxidation of canola oil . Some work has also been done using canola oil to create bio‐based polymers with improved physical properties …”

Chemically Modifying Vegetable Oils to Prepare Green Lubricants

“…The epoxidation of free fatty acids/esters/vegetable oils can be carried out in the presence of peracids through an in-situ or ex-situ process by varying the reaction parameters: reactant molar ratio, temperature, nature of the solvent, presence or absence of a catalyst (mineral acids/ion exchange resins), stirring speed, type of peroxyacid (peracetic, performic, m-chloroperbenzoic acid), mode and rate of the addition of H 2 O 2 /acetic or formic acid, the reaction period, and contacting patterns (batch/semi-batch mode/azeotropic distillation) [116][117][118]. To avoid the corrosive nature and undesirable side reactions (ring opening of oxirane) of mineral acids, heterogeneous catalyst systems such as acidic ion exchange resins [119], transition metal-based catalysts such as Ti-silica [120], Nb(V)-silica [121], sulfated-SnO 2 [122] and polyoxometalate [123] have become known recently for their ability to perform the epoxidation reaction. To characterize the epoxidation products, different analytical methods, such as measurement of the iodine value, oxirane content, FTIR, 1 H NMR, and ESIMS are performed.…”

Catalytic developments in the epoxidation of vegetable oils and the analysis methods of epoxidized products

“…These catalyst systems except HY zeolite and sulfated-SnO 2 use only H 2 O 2 as the oxidant without the need of extra acid for the epoxidation reactions, making them interesting in terms of green and recyclable conditions. These epoxidized vegetable oils were commonly used as PVC plasticizers (primary 61 and secondary [62][63][64] ) to entirely or partially replace detrimental phthalates, low-temperature lubricants, 51 and high-temperature lubricants, 65 stabilizers for PVC and starting materials to produce polyols and prepolymers in surface coating formulations and to synthesize polyurethane foams. 66,67 Epoxidized vegetable oils are intermediates for the production of isocyanate and non-isocyanate polyurethane.…”