Synthesis of high‐molecular‐weight epoxy resins from modified natural oils and Bisphenol A or BisphenolA‐based epoxy resins

Abstract

A method of synthesis of liquid high‐molecular‐weight epoxy resins from modified vegetable oils as natural raw materials is proposed. The possibility of application of epoxidized soybean, rapeseed, linseed, and sunflower oils as well as hydroxylated soybean and rapeseed oils as raw materials in the fusion process was verified. Reactions of: (i) epoxidized oils, used as low‐molecular‐weight epoxy resins, with Bisphenol A, as well as, (ii) Bisphenol A‐based epoxy resin with hydroxylated natural oils, were carried out in the presence of different catalysts (i.e., LiCl, 2‐methylimidazole, triphenylphosphine, and triethanolamine) in the temperature range of 130–160°C (depending on the catalyst type), and under nitrogen for minimization of the oxidative degradation. The epoxy value, color, number/weight‐average molecular weight, and polydispersity of the products obtained were studied in relation to the reaction conditions. Finally, the possibility of curing of the increased‐molecular‐weight epoxy resins, synthesized from the modified natural oils, with 2‐methylimidazole, dicyanodiamide, hexahydrophthalic anhydride, and triethylenetetramine was checked. The results of this research should enable reducing the use of petrochemical raw materials for the syntheses of high‐molecular‐weight epoxy resins. Copyright © 2008 John Wiley & Sons, Ltd.

The unique activity of catalyst in the epoxidation of soybean oil and following reaction of epoxidized product with bisphenol A

“…This process, involving different bisphenols and low-average-weight epoxy resins, gives the unique opportunity to synthesis the high-molecular-weight epoxy resins, which are not possible to obtain during the conventional method with the epichlorohydrin and bisfenols. Possible mechanism of fusion process of vegetable oil and BPA is (Czub, 2013(Czub, , 2009a presented on Figs. 15-17 .…”

“…The calculation of the amount of reagents used in the reaction was based on both: content of functional groups in substrates and expectation, that obtained product should have EV ≈ 0.100 mol/100 g (Czub, 2013(Czub, , 2009a. Regardless from the obvious advantage of application of natural materials instead of petrochemical raw materials, the use of vegetable oils has additional benefit, especially in the polyaddition reaction conducted by fusion method.…”

Novel bio-based epoxy-polyurethane materials from modified vegetable oils – synthesis and characterization

“…In the performed research commercially manufactured soybean oil was used. The amount of BPA was calculated basing on the change of functional groups quantity in substrates and products of the reaction, and under an assumption that the obtained product should have EV ≈ 0.100 mol/100 g [21][22][23]. The chosen catalyst, LiCl, favors the reactions of phenol groups of bisphenol A with epoxy groups over the possible reaction of secondary hydroxyl groups (obtained by oxirane ring opening) with epoxy groups.…”

“…Sienkiewicz and Czub -eXPRESS Polymer Letters Vol.11, No.4 (2017) Amounts of reagents were established with the respect to the required properties of the final product (EV ≈ 0.100 mol/100 g) [22,23]. In the first step the epoxidized soybean oil was heated to 110°C and an appropriate amount of the BPA was added.…”

“…However, we have conducted experiments on the application of isocyanates, typical for polyurethane technology, and as a result we obtained hybrid polymer materials with interesting mechanical properties [20]. Products of the epoxy fusion process of epoxidized soybean oil and bisphenol A contain a relatively large amount of free hydroxyl groups (comparable to that of polyols based on vegetable oils) [21,22], which may be susceptible to the reaction with isocyanates. The aim of this paper is to describe the synthesis of new bio-based epoxy resins and to determinate the mechanical characteristics of the obtained materials cured with isocyanates, as well as to define the influence of the used catalysts (Dabco T9 or Dabco 33-LV) on the crosslinking process and the properties of obtained materials.…”