Polymerization of 5-(1-adamantyloxy)-2H-pyrrole-2-one

Abstract

5-(1-Adamantyloxy)-2H-pyrrole-2 one has been homopolymerized and copolymerized with a variety of comonomers. Polymerization was conducted in chloroform solutions with α,α′-azobisisobutyronitrile initiator. Evidence of polymerization was achieved through infrared and NMR spectra and elemental analysis. Moderate molecular weights were achieved as determined by inherent viscosity measurements and gel-permeation chromatography. Photolysis of the polymers with ultraviolet radiation induces a photochemical rearrangement resulting in the formation of isocyanate functions. A proposed mechanism suggests α-cleavage of the carbonyl to give a 1,5-diradical which rearranges to a 1,3-diradical with subsequent ring closure to give a polymer with cyclopropyl isocyanate moieties in the backbone. DSC data show all polymers to display intense exothermic activity at temperatures near 200°C on initial heating and glass transition temperatures between 194 and 245.5°C on subsequent heating. Thermolysis of the homopolymer causes rearrangement to poly[N-(1-adamantyl) maleimide]. Reactivity ratios were determined for the systems styrene (M₁) and 5-(1-adamantyloxy)-2H-pyrrole-2-one (M₂) (r₁ = 0.06, r₂ = 0.07) and methyl methacrylate (M₁) and 5-(1-adamantyloxy)-2H-pyrrole-2-one(M₂) (r₁ = 0.35, r₂ = 0.70). Q and e values for 5-(1-adamantyloxy)-2H-pyrrole-2-one are 3.40 and 1.59, respectively.