Spectroscopic chemical insights leading to the design of versatile sustainable composites for enhanced marine application

The viability of a novel sustainable polymeric composite material, based on photocurable linseed oil resin was explored, with a view to exploiting its potential in marine environments. The study focused on a UV-curable resin subjected to setting through photoinitiated cationic polymerisation. Deployment of heterogeneous solid catalysts, containing isolated Bronsted acid centres, further improved the efficiency of cationic polymerisation, leading to enhanced thermal stability and water resistance. These features are highly desirable in the design of composite resins for marine applications. A wide range of spectroscopic, calorimetric and thermogravimetric methods as well as computational simulations have been employed to study the physico-chemical characteristics of the resin and its resistance to black and grey waste, UV resistance and hygrothermal ageing. The findings have revealed that, unlike conventional epoxy resins, the ELO resin demonstrated no decrease in glass transition temperature, Tg, despite having been exposed to different methods of ageing. In addition, the water molecules that are absorbed by the resin during hygrothermal ageing have been found to be structurally-bound through hydrogen bonding, which is supported by initial computational studies. The structure–property correlations that have been derived help to better understand the ageing process, which could be beneficial in predicting the lifetimes of these sustainable polymeric composite materials and consequently developing novel chemical methods for improving their durability and stability.