Influence of gamma irradiation on acrylate‐based shape memory polymers in the presence of various crosslinkers

Abstract

This study investigates the impact of gamma irradiation on acrylate‐based shape memory polymers (SMPs) when combined with various crosslinkers. The SMPs were synthesized using butyl acrylate (nBuA) and isobornyl acrylate (IBoA) with different crosslinkers, including polyethylene glycol diacrylate (PEGDA), bisphenol A ethoxylated diacrylate (BPAEDA), and trimethylolpropane triacrylate (TMPTA). The photo‐initiation process utilized 2,2 dimethoxy‐2‐phenylacetophenone (DMPA), followed by gamma radiation crosslinking at absorbed doses ranging from 5 to 300 kGy. The degree of gelation depended on the copolymer composition and irradiation dose, with poly(IBoA‐nBuA)‐BPAEDA exhibiting the highest gelation degree (99%) and poly(IBoA‐nBuA)‐TMPTA showing the lowest (86%). Fourier transform infrared spectroscopy analysis confirmed the copolymer structure, while thermal stability was assessed using thermogravimetric analysis and differential scanning calorimetry. Dynamic mechanical analysis analysis of the copolymers revealed significant variations in mechanical properties based on the type of crosslinker, radiation dose, and copolymer composition. Furthermore, the shape memory behavior of the copolymers was examined, demonstrating temperature‐dependent storage and loss moduli for crosslinked poly(IBoA‐nBuA) copolymers at a radiation dose of 150 kGy. In summary, the findings highlight that gamma irradiation crosslinking and the choice of crosslinkers have a substantial impact on the properties of acrylate‐based SMPs.