The action of concentrated sulphuric acid on polyethylene and polypropylene: Part 2—Effects on the polymer surface

The physical and chemical changes that occur on the polymer surfaces during the reaction between concentrated sulphuric acid and films of low density polyethylene, high density polyethylene and isotactic polypropylene at 75–125°C have been studied. Sulphonation-desulphonation reactions, leading to olefinic conjugation and, ultimately, carbonisation, are the most significant chemical changes. These, together with the disruption of the polymer surface, explain the autocatalytic evolution of SO₂ noted previously.