A novel method for preparing poly(alkyl methacrylates) and poly(methacrylic acids) of varying tacticity

✍ Scribed by Frederick P. Chlanda; L. Guy Donaruma

• Publisher: John Wiley and Sons
• Year: 1971
• Tongue: English
• Weight: 658 KB
• Volume: 15
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1971.070150514

✦ Synopsis

Abstract

In order to synthesize poly(methacrylic acid) and poly(alkyl methacrylates) over a wide range of polymer tacticity, the anionic polymerization of the following alkyl methacrylates (ethyl, n‐propyl, isopropyl, n‐butyl, sec‐butyl, isobutyl, tert‐butyl, n‐amyl, n‐hexyl, n‐octyl, n‐decyl, n‐lauryl, and n‐octadecyl) in toluene using phenylmagnesium bromide initiation was studied. It was found that the amount of isotactic polymer structure generally decreased as the size of the ester group increased. In all cases, the polymers had greater than 50% isotactic triad structure. Whether the polymerization was carried out at 0° or −78°C had little or no effect on the tacticity of the polymer produced. It was found that the poly(alkyl methacrylates) produced could be hydrolyzed in concentrated sulfuric acid to poly(methacrylic acid). The poly(methacrylic acid) produced in the hydrolysis could be esterified with diazomethane to give poly(methyl methacrylate) or with diazoethane to give poly(ethyl methacrylate) with the same tacticity as the poly(alkyl methacrylate) from which the poly(methacrylic acid) was derived. It is possible, therefore, to produce poly(alkyl methacrylates) of a desired tacticity by polymerizing the appropriate monomer, hydrolyzing, and reesterifying the resultant poly(methacrylic acid) with a diazoalkane to give the desired poly(alkyl methacrylate).