Sustainable end-chain polybenzoxazine functionalized polyethylene glycol for smart light-responsive shape-transformable structures

A novel smart light-responsive shape memory polymer based on sustainable end-chain polybenzoxazine functionalized polyethylene glycol (PBz-PEG) for utilizing as shape-transformable structure was developed in this work. The bio-derived polybenzoxazine functionalized polymer was synthesized from renewable resources via solventless two step method. The essential properties of the developed sustainable PBz-PEG influenced by molecular weight of PEG were systematically investigated. The assessment of the shape memory characteristics of the PBz-PEG was also conducted to evaluate their potential use as light-responsive shape memory polymers. Thermal properties of the PBz-PEGs were improved with the incorporation of PEG i.e., glass transition temperature (Tg) of ∼115 o C and degradation temperature at 10% weight loss (T d10 ) of ∼357 o C. Tensile properties of the PBz-PEG samples were also increased with the increasing molecular weight of PEG. Furthermore, light-responsive shape memory performance of the developed PBz-PEG samples was substantially promoted with the functionalization of PEG (shape fixity up to 92%, light-responsive shape recovery up to 96% and fast light-responsive recovering time of 45 s) and systematically studied by numerical simulation. The numerical results showed the underlying shape recovery process and predicted the stress occurred during recovery process. The results revealed that the novel sustainable end-chain polybenzoxazine functionalized PEG has a feasible use for light-responsive shape-transformable structure i.e., smart window applications.