Preparation and (13C)NMR spectroscopy of stereoregular poly(methacrylic acid)

✍ Scribed by A.J. Chapman; N.C. Billingham

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 317 KB
• Volume: 16
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(80)90159-7

✦ Synopsis

Several procedures for synthesis of stereoregular poly(methacrylic acid) have been examined and the polymer characterized by (I~C)NMR. Using d 6 DMSO as solvent for spectroscopy gives better spectra than those previously obtained using aqueous solutions and stereoehemical splittings can be resolved in the methyl signals. Free-radical polymerization in toluene solution is a Bernouilli process giving mainly heterotactic/syndiotaetic polymer. Pobmers produced with free-radical initiation in aqueous solution have a higher, and pH dependent, content of syndiotactic triads. A previously described procedure for producing regular polymers by hydrolysis of poly(trimethylsilyl methacrylate) requires modification to produce isotactic contents of above 90°,,, and does not give truly syndiotactic polymer. In contrast, polymerization with 7-radiation can produce polymers v. ith close to 90'~,, of syndiotactic triads.