Polymethyl methacrylate

Acronym and details:    PMMA, often called acrylic

Group:   thermoplastic

Developed:   1932, in commercial use from 1934, fashionable in 1960s

Trade names:   Oroglas, Perspex, Plexiglass, Lucite; Corian; Diakon

Manufacturing process:   initially thermoforming from cast sheet and fabrication; now also casting; extrusion; injection moulding

Cost:   medium

Colour:   any

Transparency:   transparent to opaque; better optical properties than glass

Rigidity:   rigid

Feel:   hard

Smell:   none

Other:   takes a high gloss; dull sound when struck

Typical uses:   aircraft glazing; containers fabricated from sheet, e.g. handbags; blocks with embedded objects, jewellery, display stands, artists ’paints

Degradation:   relatively stable; crazing resulting from stress; physical damage, especially scratches