Polythiol Crosslinked Polyesters

The addition of thiols to olefins, giving molecules with thioether or monosulfide linkages, is well documented. In the presence of peroxides or UV light, the reaction gives anti-Markownikoff addition products. Using dithiols and diolefins, a wide variety of polythioethers have been prepared and evaluated. 

Selective free-radical polyaddition of dithiols to the allylic double bonds of diallyl maleate results in the synthesis of unique sulfur containing polyester with maleic unsaturation.In the presence of base, Michael-type addition of the thiol group with the maleate double bond occurs. The unsaturated polyester may be crosslinked both by vinyl monomers, such as styrene, with peroxides or with polythiols in the presence of base. 

MA may be condensed with compounds such as 2-mercaptoethanol to give resinous materials.The carboxyl residues of these resins may be esterified to give oil additive polymers or the carboxyl polymer used in ion 

---

Many studies have appeared dealing with the properties of crosslinked polymer systems. These include adhesion of epoxy-acrylates onto tin-plate, adhesion of isocyanate and epoxy-resin coatings, adhesion of butadiene-acrylate rubbers onto metals, glass, and ceramics, adhesion of acrylic, thiol, and polyester resins to aluminium bodies, and the mechanical and physical properties of photo-crosslinkable poly(vinyl cinnamate), vinyl-divinyl copolymers,polythiols, acrylates, epoxies, and thiols,epoxy resins, polyesters on wood, ... 

---