Effect of sodium 2-acrylamido-2-methylpropanesulfonate on the structure and properties of thermoplastic polyvinyl alcohol copolymers

Thermoplastic poly(vinyl alcohol) (PVA) with water-soluble behavior has received great attention. In this work, a thermoplastic PVA was prepared via solution radical polymerization of vinyl acetate, vinyl pivalate and sodium 2-acrylamido-2-methyl propane sulfonate (SAMPS). The effects of SAMPS content on the structure and properties of modified poly(vinyl alcohol) (MPVA) were investigated. On increasing the proportion of SAMPS, the characteristic band of –OH moved to a larger wavenumber. Compared to PVA, the melting temperature (T_m) of MPVA decreased from 223.1 to 161.5 °C at 0.03 mol of SAMPS, and the initial thermal decomposition temperature (T_d) of MPVA increased from 244.3 to 262.2 °C at 0.05 mol of SAMPS. The crystallinity of the resin reduced from 51.46% to 10.21%. The enlarged difference between T_d and T_m ensured the preparation of MPVA by thermal processing. The maximum tensile strength and elastic modulus of the obtained sheets were 137.56 and 2639.32 MPa, respectively. The introduction of SAMPS reduced the alcoholysis degree from 99.03% to 95.80%. The high alcoholysis degree of MPVA meant that it could be dissolved in water at 60 °C. This type of thermoplastic PVA shows a promising application on film and textiles that require water solubility. © 2024 Society of Chemical Industry.