Surface Sulfonation of Styrene/Methyl Methacrylate Copolymers Studied by X-Ray Photoelectron Spectroscopy

✍ Scribed by Hanna Maria Kowalczynska; Pawel Mrozek; Jaroslaw Kaminski

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 334 KB
• Volume: 160
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1993.1402

✦ Synopsis

We have studied the surface composition of (styrene/methyl methacrylate) copolymers containing from 0 to (100 \mathrm{~mol} %) of styrene by X-ray Photoelectron Spectroscopy. The detailed analysis is carried out for the (C(1 s), O(1 s)), and (S(2 p)) core levels in copolymers prior to and after sulfonation with (\mathrm{SO}{3}) at gas/polymer interface. The carbon and oxygen concentrations depend strongly on styrene bulk content in unmodified copolymers. The (S\left(2 p{1 / 2}\right)) core level binding energy is found to be (169.5 \mathrm{eV}), a typical value for the sulfur in (-\mathrm{SO}{3} \mathrm{H}) group bonded covalently to carbon showing the sulfonation effect. The sulfonation of styrene mers in copolymers occurs within (3 \mathrm{~min}) when exposed to (\mathrm{SO}{3}), the surface concentrations vary in the range 39-45 and 49-56 at (%) for carbon and oxygen, respectively, and maximum (6.5 \mathrm{at} %) of sulfur is found. We have established the S/C atomic concentration ratio of 0.145 for the sulfonated polystyrene, which compares fairly well to 0.125 when each aromatic ring anchors a single (-\mathrm{SO}_{3} \mathrm{H}) group. The surface sulfur concentration is proportional to the styrene bulk content up to (50 \mathrm{~mol} %) and saturates above (80 \mathrm{~mol} %). 1993 Academic Press, Inc.