Commonly designated Polyacryl, by the abrevation PMMA or by the popular tradename Plexiglas.
Polymethylmethacrylate is an amorphous plastic which is completely transparent and absorbs visible light less than mineralic glass. Therefore the most important applications of PMMA are optical components such as lenses glasses, window shields which also can be blow molded or deep drawn to spherical shapes.
In many applications PMMA competes with Polycarbonate (PC). PMMA is far cheaper but does not achieve the excellent mechanical performance of PC.
PMMA can be plasma coated for example by scratch resistant DLC layers or by antirelection coatings.