Modified polystyrenes: Corrosion, physicomechanical and thermal properties evaluation

Coating metal surfaces with polymers is a protective method against corrosion. It is known that the introduction of anionic hydrophylic groups enhances the adhesive property and protective functionality of polymers. In the present work, polystyrene (PS) was chemically modified with succinic (SAH) and phthalic (PhAH) anhydrides in the presence of BF3·O(C2H5)2 cationic catalyst. The modified polystyrenes (MPSs) were characterized by FTIR and 1H NMR spectroscopy. The effect of various carboxylic groups bound to the PS's aromatic ring on the adhesion, corrosion, elastic properties and thermal behavior was studied in comparison with pure PS. All MPSs syntesized in this work, show strong adhesion to the substrate. The modifications enhanced the adhesion on metal surface of PS from 2% to 97–98%. Moreover, chemical modifications also enhanced the physico-mechanical properties of PS like surface hardness, tensile strength, percentage elongation and stress at maximum load. The best results were obtained for MPS with PhAH.