Polymerization of monolayers. V. Tacticity of the insertion poly(methyl methacrylate)

✍ Scribed by Blumstein, Alexandre ;Malhotra, Shadi. L. ;Watterson, Arthur C.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1970
• Tongue: English
• Weight: 758 KB
• Volume: 8
• Category: Article
• ISSN: 0449-2978
• DOI: 10.1002/pol.1970.160080913

✦ Synopsis

Abstract

Insertion poly(methyl methacrylate) (PMMA) formed within a monolayer of monomer adsorbed on montmorillonite was studied by means of NMR spectroscopy and shown to be composed of short stereosequences with a predominant isotactic component. The stereospecificity of the insertion PMMA can be understood in terms of the organization of the monomer adsorbed on the surface of the mineral. The monolayer of monomer is assumed to be composed of monads and isotactic diads due to dipole‐ion interactions between the molecules of methyl methacrylate and exchangeable cations. Results of experiments relating factors such as temperature, density of ion population of the surface, and the nature of ions are discussed. It is shown that the populations of isotactic and syndiotactic triads P~i~ and P~s~ determined experimentally in the insertion PMMA are in a reasonable agreement with values calculated from the model. It is shown, furthermore, that P~i~ increases with increase in the density of the ion population, in agreement with the equations derived from the model.