A practical route for the preparation of poly(4-hydroxystyrene), a useful photoresist material

✍ Scribed by J. Mohammed Nasrullah; S. Raja; K. Vijayakumaran; R. Dhamodharan

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 213 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(20000201)38:3<453::aid-pola9>3.0.co;2-6

✦ Synopsis

The synthesis and characterization of poly(4-hydroxystyrene) (PHS) and poly(4-vinylphenol) (PVPh) by the polymer modification route are reported. Polystyrene prepared by free-radical and anionic polymerization was acetylated quantitatively to poly(4-acetylstyrene) (ACPS) with acetyl chloride and anhydrous aluminum trichloride in carbon disulfide. The acetylation worked equally well in a mixture of 1,2-dichloroethane (DCE) and nitrobenzene containing largely DCE. The extent of the acetylation was estimated by 1 H NMR. The oxidation of ACPS was carried out with various oxidizing agents and reaction conditions. The peracetic acid oxidation in chloroform resulted in quantitative oxidation to poly(4-acetoxystyrene) (APS) as estimated by 1 H NMR spectroscopy. The treatment of APS with hydrazine hydrate in dioxane resulted in the formation of PVPh. Deacetylation occurred with equal versatility in a mixture of aqueous sodium hydroxide and tetrahydrofuran. All the polymers were characterized via gel permeation chromatography, IR, UV, 1 H NMR, and 13 C NMR spectroscopic techniques. This is the first report on the synthesis of ACPS, APS, and PHS of reasonably narrow molecular weight distributions or otherwise by the polymer modification route.