When heated it de-polymerizes and gives off styrene, which has a distinctive acrid smell.
That sounds like the styrene itself is decomposing into something else; but most descriptions of its smell (and what I'd also describe it as) are "sweet and flowery", not surprising given what it was originally isolated from: <a href="https://en.wikipedia.org/wiki/Styrene#Natural_occurrence" rel="nofollow">https://en.wikipedia.org/wiki/Styrene#Natural_occurrence
userbinator · · focus · HN ↗
That sounds like the styrene itself is decomposing into something else; but most descriptions of its smell (and what I'd also describe it as) are "sweet and flowery", not surprising given what it was originally isolated from: <a href="https://en.wikipedia.org/wiki/Styrene#Natural_occurrence" rel="nofollow">https://en.wikipedia.org/wiki/Styrene#Natural_occurrence