There are three types of resins in thermoplastic material: alkyd, hydrocarbon, and acrylic modified alkyd. Alkyd is made from natural wood-derived resins which are more resistant to oil on the ...

PMMA, polymethyl-methacrylate, is a thermoplastic acrylic linear polymer, the mer of which is illustrated in the diagram. PMMA is transparent, with a refractive index of 1.49, and easily formed into ...