Details
Material hierarchy: Polymer - Thermoplastic
The acrylics are polymers derived from acrylic acid (C3H4O2) and compounds originating from it. The most important thermoplastic in the acrylics group is polymethylmethacrylate (PMMA) or Plexiglas (Rohm & Haas's trade name for PMMA). It is an amorphous linear polymer. Its outstanding property is excellent transparency, which makes it competitive with glass in optical applications. Examples include automotive tail-light lenses, optical instruments, and aircraft windows. Its limitation when compared with glass is a much lower scratch resistance. Other uses of PMMA include floor waxes and emulsion latex paints. Another important use of acrylics is in fibers for textiles; polyacrylonitrile (PAN) is an example that goes by the more familiar trade names Orlon (DuPont) and Acrilan (Monsanto).
Acrylics have outstanding resistance to long-term exposure to sunlight and weathering. Polymethyl methacrylate (PMMA), a hard, rigid, and transparent material, is the most widely used member of the acrylic family. Cast PMMA sheet has excellent optical properties (it transmits about 92% total light) and is more resistant to impact than glass. It is not so resistant to surface scratching as glass, but surface coatings can partially overcome this limitation.
In addition to excellent optical properties, acrylics have low water absorption, good electrical resistvity, and fair tensile strength. The heat resistance of acrylics is on the order of 200°F.
Recently, modified acrylics and acrylic multipolymers that offer high impact strength and toughness in addition to the standard acrylic properties have been made available. These grades incorporate elastomeric or alloying constituents that impart added strength (up to 10 to 20 times as much as that of general-purpose acrylic crystal). Acrylics are available as compounds for molding, and casting. Extruded or cast sheet and film also are marketed.
Typical applications include outdoor signs, glazing, aircraft canopies, skylights, auto taillights, dials, buttons, lighting applications, knobs, and machine covers. Some of the transparent acrylic multipolymers have found applications in the drug and food packaging industry.
Acrylic, pronounced uh KRIHL ihk, is any one of a group of synthetic products made primarily from petroleum. Acrylics are manufactured as fibers or plastics or as substances called resins. Common acrylics include Acrilan, Lucite, Orlon, and Plexiglas.
Acrylic fibers are woven or knitted into durable fabrics of various textures. These fabrics dry rapidly and resist fading, wrinkling, and mildew. They are used to make blankets, carpets, sweaters, and other products.
Acrylic plastics are tough materials that resist weathering, sharp blows, and corrosion. Acrylic plastics are often used as substitutes for glass in such products as aircraft windows, television screens, automobile tail lights, and lighting fixtures. They are less breakable than glass but are more easily scratched.
Liquid acrylic resins are used to make paints and synthetic waxes. Acrylic paints dry quickly and provide strong protection against the weather. They are widely used as house paints and in coatings for automobiles. High-gloss acrylic waxes are spread as protective coatings on floors and automobiles.
Acrylic adhesives and sealants are made from soft, elastic acrylic resins. Acrylic adhesives are used in such products as prepasted wallpaper and tapes. Acrylic sealants are used to seal cracks and joints in buildings.
Acrylic is an amorphous thermoplastic, with an operating temperature range of -20°F (-29°C) up to 190°F (88°C). It has a low difficulty to machine. It has high impact resistance. It has superior weatherability. It has excellent transparency.