Synthesis of modified phenolic resins using renewable materials for advanced composites in civil engineering structures

摘要

[Abstract]: In this project the synthesis and characterisation of Phenolic formaldehyde resins (PF) and Phenolic formaldehyde resins modified with Cardanol (CPF) resin and natural renewable materials as thermoset fillers is investigated. The project also investigates the effect of percentage of filler by weight of renewable materials (Sawdust fibres) on the ultimate mechanical and thermal properties of the composites with PF and CPF resins.ududPhenol Formaldehyde (PF) resins are made from Benzene a petroleum product. Petrochemical supplies are finite and the economics of their use by enhancing and extending their use is of considerable interest from both an economic and resource basis. PF resins are among the most widely used thermosets because of their economics on a cost-per-volume basis. Environmental and cost concerns have lead to the search for alternative chemicals obtained from renewable raw materials to complement and/or replace PF resins.ududThe natural substitute for PF resins used in this study is Cardanol, a natural Phenolic resin distilled from cashew nut shell liquid (CNSL). CNSL itself is derived from waste cashew nut shell. Cardanol can be blended with PF resins to make Cardanol Phenolic Formaldehyde (CPF) resins, extending and complementing the PF resins. In this study fillers in the form of Sawdust are also added to extend these PF and CPF resins as they are characterised or formed.ududThis project has prepared, tested and characterised the synthesised samples based on PF resins and CPF resins. It has been found that Cardanol can effectively substitute commercial phenol in the synthesis of Phenolic resins. The Cardanol in the synthesised CPF resins has had a positive effect where the samples have been found to be less brittle and more flexible than PF resins. The sawdust fibres have also been found to be suitable fillers for composites with PF and CPF/PF resins. The composites with CPF and sawdust fibres have shown high flexibility and strength with a high glass transition temperature. These attributes make the composites suitable for potential civil engineering structural applications.