Polymerisation of αβ-Unsaturated Sulphur-containing Compounds

Abstract

A modified version of the IERM approach is applied to electron scattering from hydrogen atoms at intermediate energies to evaluate integrated cross sections for the n = 2 to n = 3 transitions. Results are compared with earlier work which overestimates these cross sections due to the omission of continuum channels. These results have important applications in astrophysics.

Polymers fromS-vinyl monomers: reactivities and properties

“…The free-radical polymerizations of vinyl sulfide derivatives lead to polymers with very high molar masses and also prove to be faster compared to their oxygen analogues, provided that the suitable initiators are used, for example azo initiators such as azobisisobutyronitrile (AIBN). 31,[35][36][37][38][39][40][41][42][43] Peroxides, on the other hand, appear not to be suitable for polymerization, since the oxidation of the sulfide to the corresponding sulfoxide or sulfone is preferred. 44 The increased reactivity of vinyl sulfides compared to vinyl ethers was demonstrated early on and already explained by Price and coworkers in 1950, 36 who observed a bathochromic shift when unsaturated sulfide molecules were excited with light compared to saturated ones.…”

“…37,56 However, this monomer class has been shown to copolymerize well not only with styrene 35,50,51,[54][55][56] but also with a variety of monomer classes such as acrylates, 35,50,55,57 methacrylates, 50,54,56 acrylonitriles, 50 vinylene carbonates, 58 vinyl ethers, 59 maleimides, 60 and diallyl compounds, 61 which is in good agreement with the calculated copolymerization parameters. 31 The reactivity of the radicals of the various comonomers decreases in relation to the vinyl sulfides in the following order: acrylonitrile > methyl acrylate > methyl methacrylate > styrene. 49,50,53 In addition, the directed synthesis of alternating polymers can also be realized due to the electron accepting properties of the monomer.…”

“…The free-radical polymerizations of vinyl sulfide derivatives lead to polymers with very high molar masses and also prove to be faster compared to their oxygen analogues, provided that the suitable initiators are used, for example azo initiators such as azobisisobutyronitrile (AIBN). 31,35–43 Peroxides, on the other hand, appear not to be suitable for polymerization, since the oxidation of the sulfide to the corresponding sulfoxide or sulfone is preferred. 44…”

“…32,75 In addition, they are also used as protective agents to prevent radiation damage and as model substances to elucidate thiol function in enzymes, which is why this class of substances has aroused quite some interest. 31,32 However, polymerization of monomers comprising thiol units is almost impossible because in most polymerizations they either act as inhibitors or as chain transfer agents. As a consequence, masking of the thiol groups is generally required.…”

“…Excellent overviews on these structures are provided in several comprehensive reviews. 16,[31][32][33][34] Interestingly, a direct covalent attachment of sulfur, in its various states, to a carbon double bond creates a set of interesting vinyl monomers, which feature some unique characteristics. For example, the conjugation with a sulfide group enables a good stabilization of a radical at the neighboring carbon atom, which renders vinyl sulfides much more reactive in radical polymerization compared to the corresponding vinyl ethers.…”