Styrophone is often made from what type of closed-cell polystyrene?
Styrophone A styrophone is an acoustic device made from expanded polystyrene foam (often referred to by the genericized trademark "Styrofoam") and it goes toot toot. There are at least two varieties:
Polyhexahydrotriazine Polyhexahydrotriazines (PHTs) are polymers of hexahydro-1,3,5-triazines, a class of heterocyclic compounds with the formula (CHNR). They are among the strongest known thermosetting plastics and are stable to solvents at pH > 3, but decompose to the monomers in acidic solutions.