Thermoplastic
A thermoplastic, or thermosoftening 'plastic', is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.
Most thermoplastics have a high molecular weight. The polymer chains associate by intermolecular forces, which weaken rapidly with increased temperature, yielding a viscous liquid. In this state, thermoplastics may be reshaped, and are typically used to produce parts by various polymer processing techniques such as injection molding, compression molding, calendering, and extrusion. Thermoplastics differ from thermosetting polymers, which form irreversible chemical bonds during the curing process. Thermosets do not melt when heated, but typically decompose and do not reform upon cooling.
Above its glass transition temperature and below its melting point, the physical properties of a thermoplastic change drastically without an associated phase change. Some thermoplastics do not fully crystallize below the glass transition temperature, retaining some or all of their amorphous characteristics. Amorphous and semi-amorphous plastics are used when high optical clarity is necessary, as light is scattered strongly by crystallites larger than its wavelength. Amorphous and semi-amorphous plastics are less resistant to chemical attack and environmental stress cracking because they lack a crystalline structure.
Brittleness can be decreased with the addition of plasticizers, which increases the mobility of amorphous chain segments to effectively lower the glass transition temperature. Modification of the polymer through copolymerization or through the addition of non-reactive side chains to monomers before polymerization can also lower it. Before these techniques were employed, plastic automobile parts would often crack when exposed to cold temperatures. These are linear or slightly branched long chain molecules capable of repeatedly softening on heating and hardening on cooling.
Acrylic
Today's acrylics industry can be divided into two distinct multibillion-dollar markets: the polyacrylic acids and its ester derivatives market, and the poly market. PMMA is also known by trade names such as Lucite, Perspex and Plexiglas. It serves as a sturdy substitute for glass for items such as aquariums, buttons, motorcycle helmet visors, aircraft windows, viewing ports of submersibles, and lenses of exterior lights of automobiles. It is extensively used to make signs, including lettering and logos. In medicine, it is used in bone cement and to replace eye lenses. Acrylic paint consists of PMMA particles suspended in water.For many decades, PMMA has been the predominant methacrylic ester produced worldwide. Major players in the PMMA market are Mitsubishi Rayon, Arkema SA, LG MMA, Chi Mei Corp., Sumimoto Chemical Company Ltd, Evonik Industries, BASF, Dow Chemical Company, AkzoNobel, Quinn Plastics and Cytec Industries. Regarding the PAA and PAc market, key manufacturers are Nippon Shokubai Company Ltd., Arkema SA and Dow Chemical Company.
ABS
is a terpolymer synthesized from styrene and acrylonitrile in the presence of polybutadiene, resulting in a long chain of polybutadiene crisscrossed with shorter chains of poly. ABS is a light-weight material that exhibits high impact resistance and mechanical toughness. It poses few risks to human health under normal handling. It is used in many consumer products, such as toys, appliances, and telephones.Nylon
belongs to a class of polymers called polyamides. It has served as a substitute mainly for hemp, cotton and silk, in products such as parachutes, cords, sails, flak vests and clothing. Nylon fibres are useful in making fabrics, rope, carpets and musical strings. In bulk form, nylon is used for mechanical parts including machine screws, gears and power tool casings. In addition, it is used in the manufacture of heat-resistant composite materials.PLA
is a compostable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch, sugar beet pulp, tapioca roots, chips or starch, or sugarcane. It is the most common material used for 3D printing with fused deposition modeling techniques.Polybenzimidazole
fiber is a synthetic fiber with a very high melting point. It has exceptional thermal and chemical stability and does not readily ignite. It was first discovered by American polymer chemist Carl Shipp Marvel in the pursuit of new materials with superior stability, retention of stiffness, and toughness at elevated temperatures. Due to its high stability, polybenzimidazole is used to fabricate high-performance protective apparel such as firefighter's gear, astronaut space suits, high temperature protective gloves, welders' apparel and aircraft wall fabrics. In recent years, polybenzimidazole found its application as membrane in fuel cells.Polycarbonate
thermoplastics are known under trademarks such as Lexan, Makrolon, Makroclear, and arcoPlus. They are easily worked, molded, and thermoformed for many applications, such as electronic components, construction materials, data storage devices, automotive and aircraft parts, check sockets in prosthetics, and security glazing. Polycarbonates do not have a unique resin identification code. Items made from polycarbonate can contain the precursor monomer bisphenol A. Susceptible to UV light, exposure results in yellowing. Degradation is especially visible in headlamps that lost or didn't have proper protective coating.Polyether sulfone
Polyether sulfone or polysulfone is a class of specially engineered thermoplastics with high thermal, oxidative, and hydrolytic stability, and good resistance to aqueous mineral acids, alkalis, salt solutions, oils and greases.Polyoxymethylene
, also known as acetal, polyacetal and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. As with many other synthetic polymers, it is produced by different chemical firms with slightly different formulas and sold variously by such names as Delrin, Celcon, Ramtal, Duracon, Kepital and Hostaform.Polyether ether ketone
is a colourless organic thermoplastic polymer in the polyaryletherketone family, used in engineering applications. It was originally introduced by Victrex PLC, then Imperial Chemical Industries in the early 1980s. It has attractive properties such as good abrasion resistance, low flammability, and low emission of smoke and toxic gases.Polyetherimide
, produced by a novel nitro displacement reaction involving bisphenol A, 4, 4’-methylenedianiline and 3-nitrophthalic anhydride, has high heat distortion temperature, tensile strength and modulus. They are generally used in high performance electrical and electronic parts, microwave appliances, and under-the-hood automotive parts.Polyethylene
is a family of similar materials categorized according to their density and molecular structure. It is obtained by polymerization of ethylene. It may be of low density or high density depending on the process used in its manufacturing. It is resistant to moisture and certain chemical agents. It is flexible at room temperature and low temperature and can be heat-sealed. As an inexpensive plastic, it is made in large amounts for varying uses. For example:- ultra-high-molecular-weight polyethylene is tough and resistant to chemicals. It is used to manufacture moving machine parts, bearings, gears, artificial joints and some bulletproof vests.
- High-density polyethylene, recyclable plastic no. 2, is commonly used as milk jugs, liquid laundry detergent bottles, outdoor furniture, margarine tubs, portable gasoline cans, drinking water distribution systems, water drainage pipes, and grocery bags.
- Medium-density polyethylene is used for packaging film, sacks and gas pipes and fittings.
- Low-density polyethylene is flexible and is used in the manufacture of squeeze bottles, milk jug caps, retail store bags and linear low-density polyethylene as stretch wrap in transporting and handling boxes of durable goods, and as the common household food covering.
Polyphenylene oxide