Synthesis of a poly(2‐hydroxyethyl methacrylate) composite with bioactive additives in supercritical carbon dioxide

Abstract

In this study, a composite of poly(2‐hydroxyethyl methacrylate) (PHEMA) with two bioactive additives, beta‐tricalcium phosphate and calcium sulfate dihydrate, was synthesized through precipitation polymerization in supercritical carbon dioxide using 2,2′‐azobis(2‐methylpropionitrile) as a free‐radical initiator. The feasible reaction temperature and pressure were screened, and the effects of monomer weight and initiator‐to‐monomer ratio are discussed. With the appropriate condition for synthesizing PHEMA with a satisfactory yield higher than 95%, two bioactive additives were introduced into the reaction medium for designing the composite. Fourier transform infrared spectroscopy, scanning electron microscopy, powder X‐ray diffractometry, energy‐dispersive X‐ray spectroscopy, and thermogravimetric and differential thermal analysis were employed to analyze the spectroscopic properties, surface morphology, crystal structure, element distribution, and thermal properties of the PHEMA composite. These results confirm the successful preparation of a PHEMA composite and demonstrate an approach to synthesizing a biocompatible composite using a one‐step and organic solvent‐free process.Highlights A poly(2‐hydroxyethyl methacrylate) composite with beta‐tricalcium phosphate and calcium sulfate dihydrate was designed in supercritical CO2. A feasible condition was screened with a satisfactory yield higher than 95%. Rough surfaces in composite particles offer potential for biomedical use.