Biodegradable Photo-Crosslinked Thin Polymer Networks Based on Vegetable Oil Hydroxy Fatty Acids

Novel crosslinked thin polymer networks based on vegetable oil hydroxy fatty acids (HFAs) were prepared by UV photopolymerization and their mechanical proper- ties were evaluated. Two raw materials, castor oil and 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) were used as sources of mono- and di-HFAs, respectively. Poly (ethylene glycol) (PEG) diacrylate and poly(e-caprolac- tone) diacrylate were synthesized and used as crosslinking agents to form crosslinked polymer networks by UV-ini- tiated free-radical polymerization with acrylated castor oil or acrylated DOD. The synthesis of acrylate derivatives was confirmed using FT-IR and 1 H-NMR spectroscopic techniques. The composition of the reaction mixture and the type/length of crosslinking agent were changed to obtain crosslinked polymer networks with various mechanical properties. For polymers prepared from high molecular weight (20,000) PEG, a 58-60% of the initial weights decreased in 35 days in phosphate buffer solution (pH 7.2) containing lipase enzyme. These potentially bio- degradable polymers based on vegetable oil HFAs can be used as eco-friendly materials for various applications to replace the existing petroleum-based polymers currently used.