Photografting on Ethylene/Propylene/5-Ethylidene-2-norbornene Rubber Initiated by Photogenerated Hydroperoxides

Abstract

Terpolymer ethylene/propylene/5-ethylidene-2-norbornene (EPDM) reacts with singlet oxygen leading to the production of polymeric pendant isolated and associated secondary hydroperoxides. Anthracene was used as a sensitizer for production of singlet oxygen under 365 nm irradiation. Irradiation (λ > 300 nm) of hydroperoxidized EPDM rubber (EPDM-OOH) in the presence of monomers grafted these monomers onto the rubber. Volatile monomers (methyl methacrylate, styrene, 2,2,6,6-tetramethyl-4-piperidyl acrylate) can be easily grafted on EPDM-OOH film by irradiation in their vapor. Nonvolatile as well as volatile monomers and some stable nitroxyl radicals were grafted onto EPDM-OOH films in methanol solution of monomers or nitroxyl radicals. Concentration of grafted monomers depends on the starting hydroperoxide concentration. Hydroperoxidation as well as grafting occurs in the films; it is not simply a surface process only.

Examination of the role of oxygen in the photografting of methacrylic acid on a polyethylene film with a mixed solvent consisting of water and organic solvents

“…It is well known that oxygen generally inhibits the radical polymerization of vinyl monomers. It has been reported, however, that during the photoirradiation of a polyethylene film in the presence of oxygen, peroxides capable of initiating grafting reactions are generally formed 13, 21–25. To clarify the effect of oxygen on the photografting of MAA under air, we examined the photoinduced formation of peroxide on an LLDPE film, and the results are shown in Figure 5.…”

Data on Specific Polymers

“…Commercial ethylene propylene diene monomer [149][150][151][152][153][154][155][156][157][158][159][160][161][162][163][164][165][166][167] has an ethylene content between 45 and 75%. Its good resistance to ozone and oxidation is due to very low unsaturation mostly in the side chains (introduced for vulcanization purpose and saturated in the process).…”

“…158 Anthracene acts as catalyst when irradiated at 365 nm and the reaction rate depends on its concentration.…”

Graft copolymerization of poly(methyl methacrylate) with some alkyl methacrylates by atom transfer radical polymerization method and thermal properties

“…The importance of graft copolymers is that they combine the properties of two immiscible polymers and act as compatibilizers for polymer blends, and can also be used as amphiphilic copolymers. Although the free radical grafting technique is usually applied to synthesize graft copolymers,5, 6 it is not suitable for preparing well‐defined graft copolymers because the side reactions, such as chain scission and crosslinking, result in loss of mechanical properties. To control the graft copolymer structure well, ionic polymerization techniques are employed 7.…”

“…Although the free radical grafting technique is usually applied to synthesize graft copolymers, 5,6 it is not suitable for preparing well-defined graft copolymers because the side reactions, such as chain scission and crosslinking, result in loss of mechanical properties. To control the graft copolymer structure well, ionic polymerization techniques are employed.…”