Design of functional macromonomer derivatives of poly(isobutylene‐co‐isoprene)

The development of new peroxide‐curable poly(isobutylene‐co‐isoprene) (IIR) elastomers is described, wherein pendant oligomerizable C=C groups are introduced in combination with a range of serviceable functional groups. Ring‐opening of itaconic anhydride with functional alcohols or amines, followed by esterification of the resulting acids with brominated IIR, yield macromonomers that crosslink efficiently under the action of dicumyl peroxide alone. More importantly, the additional graft functionality improves the physical and chemical properties of the resulting thermosets. The introduction of fluorocarbon functionality is shown to lower surface energy and improve the material's extrusion characteristics, and trialkoxysilane functionality is used to improve filler dispersion within silica‐reinforced composites. This strategy is extended to prepare thermosets bearing polymer‐bound phenolic antioxidant. Details of macromonomer production are followed by demonstrations of their utility as engineering materials.