Bio‐based and hydrolytically degradable hydroxyurethane acrylates as photocurable thermosets

Abstract

AbstractThis study focuses on the synthesis of bio‐based and hydrolytically degradable photocurable thermosets made from hydroxyurethane acrylates (HUA). The hydroxyurethanes (HUs) are prepared from the reaction between ethylene carbonate and a bio‐based diamine, Priamine 1074. Subsequently, the HU initiates the ring opening polymerization of ε‐caprolactone (CL), resulting in telechelic groups of 5 CL units at both ends of the HU. The resulting HU‐CL5 is finally acrylated to prepare the degradable HUA (HU‐CL5‐A) with transformations confirmed following each step via proton nuclear magnetic resonance (1H‐NMR) and Fourier‐transform infrared (FTIR) spectroscopies. HU‐CL5‐A is photocured with 4‐acryloylmorpholine (ACMO) as a photosensitive reactive diluent. The photocurable thermosets exhibit slight water swelling (swelling index of 46%), as Priamine 1074 and ACMO are hydrophobic and hydrophilic, respectively, leading to the slow and partial degradation of the films in water at 85°C for 14 days. The cleavage of the CL units from the film networks is proven via 1H‐NMR and FTIR, which demonstrates the main objective of this study in synthesizing photocurable and degradable HUA resins.