Study of the Reaction of Buna Rubbers with Aliphatic Thiols

Abstract

Thioglycolic acid added exothermally to butadiene polymers and copolymers in benzene solution under mild conditions to give apparent double-bond saturation values of 38 to 47 per cent. When the same polymers reacted with aliphatic thiols of C2 to C16 chain length, in mass or latex reactions, saturation values were obtained which were in accord with those found by thioglycolic acid addition. It is suggested that the double bonds in butadiene polymers and copolymers which were readily saturated by the above thiols are predominately those present in the polymer chains as vinyl side groups.

Activated Ester Containing Polymers: Opportunities and Challenges for the Design of Functional Macromolecules

“…Ever since its discovery, polymer chemists have tried different chemical reactions for PPMs to fabricate functional materials. These includes hydrogenation of rubber 3 and polystyrene, 4 modification of polybutadiene backbone via thiol−ene addition, 5 chlorination of polystyrene−divinylbenzene used in solid-phase peptide synthesis, 6 modification of polymers with pendent epoxide functionalities, 7,8 and many more. 9,10 However, many of those earlier examples of PPMs suffered from nonquantitative installation of functional groups due to poor reaction efficiency and required harsh reaction conditions that often lead to potential defects within the polymer structures.…”

Branched Hydroxyl Modification of SBS Using Thiol-Ene Reaction and Its Subsequent Application in Modified Asphalt

“…On the basis of the thiol-ene radical addition reaction, MCH can react with the double bonds of PB segments in SBS. Also, according to the reactivity order of double bonds, 45 there are two cases presented for the thiol-ene reaction (see Figure 1). Case I represents MCH only reacting with the 1,2-vinyls (i.e., 1,2-CC), while case II is with both 1,2-vinyls and 1,4-units (i.e., 1,4-CC).…”

“…Another important theory should be noticed; that is, Serniuk et al 45 reported that the reactivity order of double bonds of PB in the thiol-ene reaction was 1,2-vinyl ≫ 1,4-cis > 1,4-trans, which could be considered as a kind of pseudo-selectivity, allowing the thiol would be only added to the 1,2-vinyls under a certain condition. Yu and Zheng 46 modified SBS (M̅ n ≈ 17.8 kg/mol, m PB /m PS = 5.6:4.4, n 1,2-vinyls /n 1,4-units = 6.5:3.5) with 3mercaptopropyl-triethoxysilane (MPTES; n MPTES /n CC /n AIBN = 100:10:1) at 60 °C for 48 h; their results indicated that all double bonds, including 1,4-units, almost reacted through the thiol-ene reaction.…”

Thiol-Ene Coupling of High Oleic Sunflower Oil towards Application in the Modification of Flexible Polyurethane Foams

“…The addition of thiols to unsaturated compounds was discovered in 1905 by Posner [9] and applied for the first time in 1948 [10]. This reaction proceeds in an anti-Markovnikov manner using metal-catalyzed complexation [11] or free radical mechanism [12][13][14] and can be initiated photochemically by ultraviolet (UV) light (wavelength 200-400 nm) and photoinitiators, or thermally in the presence of radical initiators.…”