thermoplastic
ther‧mo‧plas‧tic /ˌθɜːməʊˈplæstɪk◂ $ ˌθɜːrmə-/
noun [uncountable and countable]
technical a plastic that is soft and bendable when heated but hard when cold
ther‧mo‧plas‧tic /ˌθɜːməʊˈplæstɪk◂ $ ˌθɜːrmə-/
noun [uncountable and countable]technical a plastic that is soft and bendable when heated but hard when cold