Study of the Reaction of Buna Rubbers with Aliphatic Mercaptans¹

Thiol‐Ene Radical Addition of L‐Cysteine Derivatives to Low Molecular Weight Polybutadiene

“…The order of reactivity 1,2->> 1,4-cis > 1,4-trans units was first observed by Serniuk et al; [13] a similar trend of the addition rates was especially confirmed by 'model reactions' between thiols and simple olefins resembling the structural units of PBL-type rubbers (for instance, internal cis-and trans-or terminal olefines). [13][14][15] This interesting order of reactivity was also observed in later studies on similar model compounds [16][17][18][19][20][21] or with unsaturated polymers. [16][17][18][19][20][21][22][23][24][25][26][27][28] Another remarkable mechanism aspect was a noticeable anti-Markovnikov behaviour of the addition reaction.…”

“…Cunneen was looking for new cross-linking methodologies through the addition of dithiols or dithioacids (acting as inter-macromolecular bridges), or by using alkali bases on carboxy-functionalised NR (with thioglycolic acid, TGA). Marvel et al [11] and Serniuk et al, [12,13] in the same years, developed similar procedures in order to obtain oil-resistant rubbers; they used TGA, 2-mercaptoethanol and other polar thiols as functionalising agents for NR, PBs with different amounts of structural units, and SBR. The important role played by the radical initiator soon became evident, since the functionalisation degrees were much higher in presence of an initiator than when using bare UV light acting as a radical generator.…”

“…The important role played by the radical initiator soon became evident, since the functionalisation degrees were much higher in presence of an initiator than when using bare UV light acting as a radical generator. [7,12,13] The addition of polar thiols to liquid PB was first studied by Oswald. [14] The high functionalisation degrees, in this case, indicated that large amounts of polar thiols could be added to PBLs, thereby obtaining new materials with modulated hydrophilicity.…”

Synthesis of Functional Polymers by Post‐Polymerization Modification

“…The radical addition of thiols to polymeric alkenes such as 1,2-butadiene and natural or synthetic rubber has been known for some time, [84][85][86][87][88][89] and it has recently been revived as a means of modifying polymers. In the presence of a suitable radical source or under UV irradiation, thiols undergo addition to alkenes predominantly in anti-Markovnikov fashion.…”

Advances in Click Chemistry for Single-Chain Nanoparticle Construction

“…For natural polymers, the first report of sulfur-modified natural rubber was made independently about 1840 by Hancock, Ludersdorf and Goodyear [46]. Concerning synthetic polymers, the functionalization of butadiene polymers via thiol-ene addition was reported by Serniuk et al [47] in 1948. Chlorinated polystyrene-divinylbenzene beads for ion exchange were developed by Pepper et al [48] in 1953 and resins for solid-state peptide synthesis by Merrifield [49] on 1963.…”