What are the main downstream applications of isoprene beyond synthetic rubber?

What are the main downstream applications of isoprene beyond synthetic rubber?
While rubber applications dominate—consuming roughly 77% of isoprene output for isoprene rubber, SIS block copolymers, and butyl rubber—the fine chemical segment is growing in strategic importance. Isoprene serves as a building block for methyl heptenone, linalool, and citral, which feed into vitamin A and E production, as well as fragrances. It also converts to isopentenol, a precursor for pyrethroid insecticides via the intermediate bethoxazin. Notably, integrated producers like NHU leverage isoprene cost advantages in vitamin synthesis, where raw material price moves of only 9-12% contrast with 18-26% swings in vitamin prices, expanding margins. Emerging applications include butadiene-isoprene copolymers with superior fatigue and low-temperature performance, though not yet commercialized. This diversification insulates isoprene demand from single-sector cyclicality.