Last modified: 2018-07-27
Abstract
Increasingly high demand for composite materials is being recorded, creating a dilemma, especially for researchers. For some time now, a lot of work has been done on bio-sourced resins, derived from local plants such as eucalyptus in order to replace synthetic resins in the production of composites.
Recently, there has been a growing interest in tannin resins for their low cost and also for their availability. Tannins are natural phenolic compounds, which have been extensively researched for the development of a wide range of industrial applications.
In the first place the tannins are extracted (solid / liquid extraction) from the eucalyptus bark, optimization of the operating conditions proved necessary to determine the best extraction conditions giving the highest yields with the highest concentration in polyphenols (tannins), a complete characterization is carried out later (ATG, DSC, RAMAN, FTIR and DRX).
Resins and foams based on phenol and furfuryl alcohol are synthesized with a progressive substitution of phenol (toxic product) by polyphenols (tannins) extracted from the eucalyptus bark, a 50/50 phenol / polyphenol substitution gave excellent results in terms of mechanical properties for the resins whereas for the foam we could have quite good properties desired with a ratio of 20/80, characterizations both chemical and mechanical (ATG, FTIR, RAMAN, DRX, study of the swelling rate, freezing time, friction test and TMA) are performed.
Composite materials based on bio-sourced resins and foams are being developed to replace synthetic materials in different industrial sectors.