Thermoplastic
This article needs additional citations for verification. (March 2021) |
A thermoplastic, or thermosoftening plastic, is any plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.[1][2]
Most thermoplastics have a high
Above its
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: on one hand the polyacrylic acids (PAA) and its ester derivatives (PAc) market, on the other hand, the poly(methyl methacrylate) (PMMA) market.[5] 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 (Japan), Arkema SA (France), LG MMA (South Korea), Chi Mei Corp. (Taiwan), Sumimoto Chemical Company Ltd (Japan), Evonik Industries (Germany), BASF (Germany), Dow Chemical Company (U.S.), AkzoNobel (The Netherlands), Quinn Plastics (UK) and Cytec Industries (U.S.). Regarding the PAA and PAc market, key manufacturers are Nippon Shokubai Company Ltd. (Japan), Arkema SA (France) and Dow Chemical Company (U.S.)
ABS
. 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
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, whereas, 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
Polybenzimidazole
Polybenzimidazole (PBI, short for Poly-[2,2’-(m-phenylen)-5,5’-bisbenzimidazole]) 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, toughness at elevated temperature. 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
Polycarbonate (PC) 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 (BPA). 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 (PES) or polysulfone is a class of specially engineered thermoplastics[6] with high thermal, oxidative, and hydrolytic stability, and good resistance to aqueous mineral acids, alkalis, salt solutions, oils and greases.
Polyoxymethylene
Polyoxymethylene (POM), 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
Polyether ether ketone (PEEK) is a colourless organic thermoplastic polymer in the polyaryletherketone (PAEK) family, used in engineering applications. It was originally introduced by Victrex PLC, then ICI (Imperial Chemical Industries) in the early 1980s. It has attractive properties like good abrasion resistance, low flammability and emission of smoke and toxic gases.
Polyetherimide
Polyetherimide (PEI), 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
Polyethylene (polyethene, polythene, PE) is a family of similar materials categorized according to their density and molecular structure. It is also known as poly and is obtained by the addition polymerisation of ethylene. It may be of low density or high density depending upon the process used in its manufacturing. It is resistant to moisture and most of the chemicals. It is flexible at room temperature (and low temperature) and can be heat sealed. Since it is an inexpensive plastic it is made in large amounts to cater to the demand. For example:
- ultra-high-molecular-weight polyethylene (UHMWPE) 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 (HDPE), 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 (MDPE) is used for packaging film, sacks and gas pipes and fittings.
- Low-density polyethylene (LDPE) is flexible and is used in the manufacture of squeeze bottles, milk jug caps, retail store bags and linear low-density polyethylene (LLDPE) as stretch wrap in transporting and handling boxes of durable goods, and as the common household food covering.
Polyphenylene oxide
Polyphenylene sulfide
Polyphenylene sulfide (PPS) obtained by the condensation polymerization of p-dichlorobenzene and sodium sulfide, has outstanding chemical resistance, good electrical properties, excellent flame retardance, low coefficient of friction and high transparency to microwave radiation. PPS is principally used in coating applications. This is done by spraying an aqueous slurry of PPS particles and heating to temperatures above 370 °C. Particular grades of PPS can be used in injection and compression molding at temperatures (300 to 370 °C) at which PPS particles soften and undergo apparent crosslinking. Principal applications of injection and compression molded PPS include cookware, bearings, and pump parts for service in various corrosive environments.
Polypropylene
Polystyrene
Polystyrene is manufactured in various forms that have different applications and can have medium to very low density. Extruded polystyrene (PS or xPS, sometimes colored pink/blue) is used in the manufacture of disposable cutlery, rigid ground contact rated insulating foam board, CD and DVD cases, plastic models of cars and boats, and smoke detector housings. Expanded polystyrene foam (EPS or "styrofoam", white) is used in making insulation and packaging materials, such as the "peanuts" and molded foam used to cushion fragile products. Polystyrene copolymers are used in the manufacture of toys and product casings.
Polyvinyl chloride
PVC is produced in many specific modifications to affect its chemical and physical properties. In plasticized polyvinyl chloride (pPVC), plasticizers are added to the raw material before molding to make it more flexible or pliable. Early on, the health and environmental aspects of this were poorly understood and replacements and product bans resulted after studies. The original form is often referred to as unplasticized polyvinyl chloride (uPVC), which is the more commonly used type for installations such as water, waste, and sewer conveyance plumbing.
Chemical modification often produces more drastic changes in properties.
Polyvinylidene fluoride
Polyvinylidene fluoride,
Polytetrafluoroethylene (Teflon)
See also
References
- ^ "Thermosoftening plastics and Thermosetting plastics" (PDF). lgschemistry.org.uk. Archived from the original (PDF) on 20 September 2008. Retrieved 12 March 2021.
- doi:10.1016/j.polymer.2006.05.076.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ A. V. Shenoy and D. R. Saini (1996), Thermoplastic Melt Rheology and Processing, Marcel Dekker Inc., New York. Archived 2015-04-14 at the Wayback Machine
- ^ Charles P. MacDermott and Aroon V. Shenoy (1997), Selecting Thermoplastics for Engineering Applications, Marcel Dekker Inc., New York. Archived 2015-04-14 at the Wayback Machine
- ISBN 978-1-4665-7722-0, 2016
- S2CID 136747839.
- ^ j.lerouge (2020-12-26). "What the Heck Is Sofubi?! 10 Things You Didn't Know About Soft Vinyl". Invasion Toys News. Retrieved 2022-07-08.
- ^ "How does CPVC piping compare to metal piping?". Corzan Industrial Systems.
- ^ "Chemical Resistance of Thermoplastics Piping Materials TR-19/2007" (PDF). Plastic Pipe Institute, Inc. (PPI).
- ^ "PVDF Performance Characteristics & Data" (PDF). Arkema.
External links
- Media related to Thermoplastic at Wikimedia Commons