Synthesis of Hydrophobically Associating Polymers with Natural Product Structures by a One‐Pot Method – Comparison of Ethanol Treatment and Freeze‐Drying

Abstract

Polyacrylamide‐based hydrophobically associating polymers (HAPAM) containing capsaicin derivatives and itaconic acid with acrylamide (AM) and methacrylic acid (MAA) as the main bodies, and N‐vinylpyrrolidone (NVP) as the functional monomer are prepared by a one‐pot synthesis of the soap‐free emulsion polymerization process. The structure is characterized by fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (1H NMR), and thermal gravimetric analyzer (TGA) explores thermal stability. For achieving proper purification, excellent preservation and convenient transportation of the polymer and to advance its practical engineering applications, two different treatments, namely ethanol washout and freeze‐drying, are carried out and compared. The surface morphology observation manifests that the freeze‐drying products (DHPAM) better protect the three‐dimensional cross‐linked network structure formed by various supramolecular forces such as hydrophobic association, electrostatic and hydrogen bonding inside the polymer than the ethanol washout products (EHPAM), which well explains why DHPAM has lower critical association concentration (CAC), greater resistance to high temperature and high salt, and better corrosion inhibition performance than EHPAM. It is significant for strengthening the application of polymers in related fields, especially oil and gas extraction.