Styrene/phosphonic acid copolymers: Synthesis and thermal, mechanical, and electrochemical characterization

Abstract

In this study, a series of poly(styrene-covinyl phosphonic acid) [P(S-co-VPA)] copolymers were synthesized by the free-radical copolymerization of styrene and vinyl dimethyl phosphonate followed by alkaline hydrolysis. The P(S-co-VPA) copolymers were characterized by size exclusion chromatography (gel permeation chromatography), Fourier transform infrared vibrational spectroscopy, proton nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and electrochemical impedance spectroscopy. Despite the difference between the copolymerization ratios of styrene and vinyl dimethyl phosphonate, the resulting copolymers presented single glass transitions at temperatures that depended on the acidic group amount. The glass transition shifted to a higher temperature and became broader as the amount of phosphonic acid increased. The storage modulus at temperatures higher than the glass transition also increased with increasing acidic groups because of intramolecular and intermolecular interactions. All of the acid copolymers were thermally stable to at least 300 C. A high oxidative stability was found for 3 : 1 P(S-co-VPA), which also presented conductivity values on the order of 10 À6 X À1 cm À1 at room temperature. The 1 : 1 P(S-co-VPA) membrane presented Arrhenius-type behavior at temperatures from 30 to 80 C and conductivity on the order of 10 À5 X À1 cm À1.

Synthesis and Characterization of Poly(vinylphosphonic acid-co-acrylic acid) Copolymers for Application in Bone Tissue Scaffolds

“…This is due to the difficult polymerization of vinylphosphonic acid (VPA), which has been demonstrated by Bingöl et al The free radical polymerization proceeds via cyclopolymerization of VPA anhydride, which leads to a very slow rate of reaction. This has previously been observed for VPA copolymerization with monomers such as styrene, vinylpyrrolidone, and methyl acrylate . Therefore, when the VPA content in the feed is high, it is very difficult to produce high molecular weight polymers.…”

Mechanical and Dynamic Mechanical Analysis of Proton‐Conducting Polymers

“…On a series of poly(styrene-co-vinyl phosphonic acid) (P(S-co-VPA)) copolymers, Santos [65] followed on the dynamic mechanical properties the influence of the S/VPA ratio. The a relaxation temperature of the acid copolymers increased as the amount of phosphonic acid increased, which was mainly attributed to hydrogen bond interactions between the acid groups of the copolymers.…”