Biodegradable polymeric networks of poly(propylene fumarate) and phosphonic acid-based monomers

Poly(propylene fumarate) (PPF) was crosslinked with vinyl phosphonic acid (VPA) and vinyl phosphonic acid diethyl ester (VPES) to prepare biodegradable and biocompatible polymers with a network structure. Intended for this purpose, the PPF pre-polymer was synthesized through a polycondensation reaction of propylene glycol and fumaric acid in an excess of propylene glycol. The PPF pre-polymer was then thermally cured with various ratios of VPA and VPES in the presence of benzoyl peroxide initiator via radical polymerization. Complete cure of PPF/VPA and PPF/VPES copolymers was confirmed by differential scanning calorimetry, crosslink density was determined via swelling experiments, and thermomechanical properties and thermal degradation profiles were characterized by dynamic mechanical and thermogravimetric analyses, respectively. Various compositions of the PPF/VPA and PPF/VPES copolymers exhibited compressive modulus values in the wide range 10-836 MPa and compressive strength values in the range 14-119 MPa. The equilibrium water content of the PPF/VPA and PPF/VPES copolymers ranged from 4 to 20.5 wt%. Biodegradation rate of the polymers in buffer solution at 37 degrees C, examined via both weight loss and pH measurements, was significantly influenced by the co-monomer and initiator compositions. Combining the results of these studies indicated that PPF/VPA and PPF/VPES copolymers show potential for applications as bone tissue engineering scaffolds. Moreover, just varying PPF and co-monomer ratio and initiator amount provides adjustable and controllable characteristics of the end product. (c) 2020 Society of Industrial Chemistry