Copolymers of acrylates with sulfur dioxide: Synthesis and structural studies by ¹³C NMR spectroscopy

Abstract

The copolymerization of sulfur dioxide with methyl, ethyl, butyl or 2-ethylhexyl acrylate was studied. The influence of the composition of monomer feed and reaction temperature on the composition of the copolymers was investigated. The maximum content of sulfonyl units in the copolymers, obtained at -78 "C, was found to be ca. 30 mol-Yo and to decrease with increasing temperature. The sequence distribution in the copolymers was determined by I3C NMR spcctroscopy. It was proved that acrylates do not undergo alternating propagation with SO,, and the minimum number of acrylate monomeric units in a homosequence is 2. The results obtained were compared with those obtained from studies on the copolymerization of SO, with other monomers, and are discussed in terms of the alternating copolymerization theory and the penultimate model. Experimental partThe method of purification of the monomers and solvents and also the copolymerization procedure and copolymer isolation were described previously"). The copolymer compositions were determined by elemental analyses and on the basis of I3C ['HI NMR spectra of the products. NMR spectra were recorded at room temperature on a Varian NFT-20 spectrometer.Deuterochloroform was used as solvent and HMDS as an internal standard. The signal area in the carbon resonance was compared by the peak weighing method. 0025-1 16)</88/$03.00 P x' P 3.