Epoxy resins represent a major class of thermosetting resins that be combined with a wide range of curing agents, finding a diverse range of applications in coatings, adhesives, composites, electrical encapsulation, etc. With the growth of the bio-based economy, the chemical sector is increasingly looking towards using biomass-derived molecules and materials with new functionality, enhanced performance attributes, and low carbon footprints. With this goal in mind, bio-based epoxy resins are drawing more and more attention.
Synthesis of Bio-based Epoxy Resins
The most commonly used epoxy prepolymer is bisphenol A diglycidyl ether (BADGE), which is commercially produced from bisphenol A (BPA) and epichlorohydrin, as shown in figure 1. Thus, the productions of bio-based epichlorohydrin and bio-based alternatives of bisphenol A are the keys to the biosynthesis of epoxy resins.
Fig. 1 Synthesis of epoxy resin
- Synthesis of bio-based epichlorohydrin
Historically, epichlorohydrin has been produced by the treatment of allyl chloride, a chlorinated derivative of petrol-derived propylene. While the large amounts of by-product glycerin from biodiesel production can be used as a raw material for producing of epichlorohydrin.
Fig. 2 A glycerol-to-epichlorohydrin (GTE) process
- Synthesis of bio-based alternatives to bisphenol A
Bisphenol A is an oil-derived, large market volume chemical with a wide spectrum of applications in plastics, adhesives and thermal papers. However, bisphenol A is not considered safe due to its endocrine disrupting properties and reproductive toxicity. A number of alternative carbon sources, such as lignocellulose, together with cellulose, hemicellulose and lignin, terpenes, terpenoids and triglycerides, can be used for the manufacture of bio-based alternatives to bisphenol A (figure 3) [1, 2].
Fig. 3 Sketches of the main bisphenol A substitute types recently proposed from biomass
Properties and Applications
Bio-based epoxy resins exhibit certain properties which make them more attractive than other epoxy resins present in the market. Some of these properties are no nasty smell, relatively superior to petrol-based epoxy resins, low VOC, low odor, superior strength and UV resistance transparency. As the excellent properties, bio-based epoxy resins can be used in many industries, including coatings, adhesives, composites, laminates, and electronic materials such as potting compounds. The types of bio-based epoxy resins and their applications are listed as following:
| Epoxidized linseed oil | composites, adhesives, laminates |
| Liquid epoxidized natural rubber [LENR] | epoxy composites |
| Terpene-maleic estertype epoxy [TME] | composite coatings |
| Diglycidyl ethers of isosorbide [DGEI] | epoxy resins in food industry |
| Furan diepoxy of 2,5-bis(hydroxymethyl)-furan [BHMF] | adhesives |
| Epoxidized cardanol | coatings |
Our Bio-based Epoxy Resin
Alfa Chemistry provides a range of epoxy resin which are based on renewable raw materials.
| Catalog | Viscosity (Pa·s) | Epoxy index (mol/kg) | Download |
|---|
| BIOS-EP510 | 12.5-16.0 | 5.18-5.46 | |
| BIOS-EP520 | 12.0-14.5 | 5.21-5.50 | |
| BIOS-EP525 | 10.0-12.0 | 5.29-5.59 | |
| BIOS-EP530 | 8.0-10.0 | 5.38-5.68 | |
Alfa Chemistry is a professional supplier of bio-based epoxy resins. For high quality products, professional technical service, use suggestion and latest industry news, please feel free to contact us.
References
- Van de Pas, D. J., & Torr, K. M. Bio-based Epoxy Resins from Deconstructed Native Softwood Lignin. Biomacromolecules, 2017, 18(8), 2640–2648.
- Liguori, F., Moreno-Marrodan, C., & Barbaro, P. Biomass-derived chemical substitutes for bisphenol A: recent advancements in catalytic synthesis. Chemical Society Reviews, 2020.
Our products and services are for research use only.
