Application of Cyrene solvent for the fabrication of polymethyl methacrylate, polyethyl methacrylate and composite films containing hydroxyapatite and diamonds

Abstract

Cyrene is a new biodegradable solvent, which represents a green alternative to many traditional toxic solvents for advanced polymers. Therefore, this investigation is motivated by interest in applications of Cyrene for polymer processing. The feasibility of solubilization of polymethyl methacrylate (PMMA) and polyethyl methacrylate (PEMA) in Cyrene is demonstrated. The ability to form relatively concentrated solutions of the high molecular mass polymers is an important factor for the formation of PMMA and PEMA films by a dip coating method. It was found that the polymer coatings provide corrosion protection of stainless steel in 30 g L−1 NaCl solutions. Another important finding is that the use of Cyrene facilitates the fabrication of stable suspensions of hydroxyapatite (HAp), microdiamond, and nanodiamond particles. Therefore, the problems of the dispersant selection for dispersion of chemically inert diamond and development of biocompatible dispersants are avoided using Cyrene. For the fabrication of composite films, HAp nanorods with reduced particle size are obtained using rutin as a chelating capping agent. Composite films containing HAp, microdiamond and nanodiamond in the PMMA or PEMA matrix are obtained. The composite films are promising for biomedical applications. It was found that the film morphology, composition and microstructure are influenced by the solvent–particle–polymer interactions and processing conditions.