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Natural polymers (from the Greek poly meaning "many" and meros meaning "parts") are found in many forms such as horns of animals, tortoise shell, shellac (from the lac beetle), rosin (from pine trees), asphalt, and tar from distillation of organic materials.
Polymers are substances containing a large number of structural units joined by the same type of linkage. These substances often form into a chain-like structure. Polymers in the natural world have been around since the beginning of time. Starch, cellulose, and rubber all possess polymeric properties. Man-made polymers have been studied since 1832. Today, the polymer industry has grown to be larger than the aluminum, copper and steel industries combined.
Polymers already have a range of applications that far exceeds that of any other class of material available to man. Current applications extend from adhesives, coatings, foams, and packaging materials to textile and industrial fibers, composites, electronic devices, biomedical devices, optical devices, and precursors for many newly developed high-tech ceramics.
About heat resistant plastics
"If we look around in an aircraft, most of what you see is not metal, it's polymeric the walls, the bins, the seats, the windows, just about everything except the chair supports," says University of Massachusetts Professor Phillip Westmoreland, lead author of the study. Although polymers don't actually burn, Westmoreland points out, they decompose from heat and many of them produce gases that burn.
High temperature resistant plastics are being increasingly used in the production of motor components and gears, hot fuel systems, and air manifolds in automobiles that would have degraded earlier-generation polymers. However, high costs and lingering doubts among potential end users about the efficacy of these plastics are holding back their adoption. One of the toughest uses for plastics in automotive motors is in bearings, which have to withstand high temperatures as well as pressures, wear, and chemical aggression to be proven effective. Moreover, plastics processing, when compared to metalworking, is extra sensitive to environmental factors, such as humidity.
This Technical Insights research service analyzes the advances in high temperature plastics for motors and gears, segmenting it by automotive, marine, oil and gas, materials handling, industrial machinery, and aviation applications. In addition to discussing the various technology drivers and restraints, the study also covers research and development efforts at various universities, leading companies, and other research institutions across the globe. This comprehensive research service helps participants identify potential collaborators, stay ahead of competition, and keep abreast with critical developments.
Applications of Polymers:
Agriculture and Agribusiness
Polymeric materials are used in and on soil to improve aeration, provide mulch, and promote plant growth and health.
Many biomaterials, especially heart valve replacements and blood vessels, are made of polymers like Dacron, Teflon and polyurethane.
Plastic containers of all shapes and sizes are light weight and economically less expensive than the more traditional containers. Clothing, floor coverings, garbage disposal bags, and packaging are other polymer applications.
Automobile parts, windshields for fighter planes, pipes, tanks, packing materials, insulation, wood substitutes, adhesives, matrix for composites, and elastomers are all polymer applications used in the industrial market.
Playground equipment, various balls, golf clubs, swimming pools, and protective helmets are often produced from polymers.
Introduction about their types:
The demands made by product designs and markets are growing continuously. Important leading indicators for high quality growth are new and improved materials. The materials of the future in particular, the high performance plastics, are opening up new technical possibilities for innovative products. High performance plastics materials maintain twenty-five percent or better of their room temperature properties at 310 °F and higher, are stronger, and have important characteristics, such as chemical resistance, stiffness, fire retardance, composite processability, and others, to stretch the boundaries of plastics applications.
Elastomer Modified PPS Xtel XK Alloys
Chevron Phillips Chemical Co. has a family of elastomer modified polyphenylene sulfide (PPS) alloys called the Xtel XK Series, which offer properties unique to the polyphenylene sulfide family. The Xtel XK Series compounds are high-performance PPS-based alloys developed to provide an excellent combination of mechanical and electrical properties along with excellent flow in thin walls, low flash characteristics, and fast cycle times. The addition of these alloys to the Ryton PPS line of products broadens the reach of this material. The new Xtel resins withstand harsher chemical exposure at higher temperatures with more ductility and strength retention than conventional PPS grades. Previously, adding flexibility and strength resulted in a trade-off, which meant giving up heat resistance. Now, a proprietary olefinic copolymer technology developed by Chevron Phillips R&D has eliminated that trade-off.
High Surface Quality, Reduced Warpage Polyphthalamides (PPAs)
Polyphthalamide (PPA) from Ems-Chemie is now available in combined mineral and glass reinforced grades for better surface quality, reduction of warpage, and more uniform thermal expansion. Grivory HT is a thermoplastic material based on a semi-crystalline, partially aromatic co-polyamide-PA6T/X. The main distinguishing feature of Grivory HT, when compared to other well known polyamides is its better performance values at high temperatures. Grivory HT bridges the gap between the property values of engineering plastics and those of high-performance plastic materials.
Until now, the Grivory HT product range from EMS-GRIVORY comprised only glass fiber or mineral reinforced grades. This product range has now been supplemented by the introduction of three hybrid polyphthalamide pilot products based on (PA6T/6I). As a result of the combination of glass fibers and mineral used as reinforcement, these new products exhibit a low tendency to warp, more uniform thermal expansion and improved surface quality, in addition to high stiffness and strength and temperature resistance. They are suitable for the manufacture of molded parts with tight tolerance requirements. The designations of these new products are: Grivory HT XE 3844, Grivory HT XE 3845 and Grivory HT XE 3853. Grivory HT XE 3853 is available in black or natural, the other two products in black. Applications for these new products are in automotive (electronic control units, brush holders, motor end plates, belt pulleys and throttle bodies), as well as in a variety of electrical/electronic and mechanical engineering applications.
Micromolding Medical Grade Polyamide-Imide (PAI)
Solvay Advanced Polymers' Torlon polyamide-imide (PAI) offers the advantages of a thermoset, in that once cured, it provides unstoppable performance in some of the most severe service environments. But like a thermoplastic, it can be processed by standard methods such as injection molding, extrusion and compression molding. Torlon resin combines exceptional strength at high temperature with excellent resistance to creep, wear and chemicals including organic solvents. Yet parts made from Torlon resin are lightweight-a major advantage over metal parts. Precision components made from Torlon polyamide-imide are said to be virtually indestructible, making them a strong performer for demanding electronic handling operations.
Now, Torlon polyamide-imide is breaking into the precision micromolding arena. A precision micromolded component made from Torlon 4203L that is part of a larger medical device used in cardiovascular repair procedures is being produced by Rapidwerk. RapidWerk's ability to mold a very complex, miniature component weighing only 4.2 milligrams and having metal-like performance marks a technological breakthrough for the Chicago-based injection molding and micromolding company.
Torlon PAI selected by RapidWerks for precision micromolded components used in cardiovascular repair
Fabrication is easier and less expensive than machining metal parts, typically costing 25-30 times less than converting stainless steel from raw material to the finished part. Torlon resin's unique ability to combine high strength at temperatures up to 260 °C with excellent resistance to creep and wear helped make this possible. Since the component operates at several thousand RPM's under a load, Rapidwerk needed a low-friction material that provided exceptional strength and wear resistance and as a significant amount of heat is generated during the procedure, they also needed a material that was stable at high temperature.
Lead Free Solder Resistant Thermx PCT Polyester
DuPont's Thermx PCT is high performance polyester that is able to withstand higher temperatures than standard polyesters while retaining dimensional stability and chemical resistance. For connectors and other electronic components, the material can withstand surface-mount assembly conditions, including use of lead-free solder.
Electronic connectors molded from DuPont Thermx PCT
The material withstands high-temperature assembly of SMT reflow soldering, retains useful strength and toughness with age in high temperature service, and is chemically resistant to auto fluids, circuit board cleaning agents and other chemicals. It also has excellent colorability, good dimensional stability with negligible moisture effect and is arc tracking resistant, a valuable asset for 42-volt auto electrical applications. Thermx PCT has a very high melting temperature of 285°C. It also exhibits excellent dielectric properties at elevated temperature. Applications include a wide range of injection molded components for electrical, electronics, automotive, appliance, and other industrial and consumer products. Typical parts include circuit board connectors, automotive connectors (headers), lamp sockets and relays.
MSD Ignition, a world leader in performance automotive ignition technology, is now using Thermx PCT high performance polyester for coil forms in its MSD ignition coils.
Ignition coil bobbin of Thermx PCT
The first MSD coil to go to Thermx PCT is the Blaster SS, often mounted one-per-cylinder in modified street cars and stock car racers. Made with efficient E-core windings, Blaster SS packs 300 milliamps at up to 40,000 volts. Blaster SS coils using a bobbin molded from Thermx PCT can withstand open-circuit bench tests conducted by MSD Ignition at 70,000 volts, the limit of its test rig, with no arcing, or cracking of the coil form.
Specialty Amorphous Polysulfones (PSOs)
Polysulfones (PSO) are clear, rigid, tough thermoplastics, and are characterized by the presence of sulfone linkages in their repeating units.
(Source: Solvay Advanced Polymers)
Chain rigidity is derived from the relatively inflexible and immobile phenyl sulfone groups and toughness from the connecting ether oxygens. As a class, polysulfones have high strength and very high service temperature and show excellent thermal stability, low creep, good dielectric properties, transparency, self-extinguishing, and resistance to chemicals.
Self Cleaning Polysulfone Application
Solvay Advanced Polymers Udel polysulfone excels in many fluid handling applications. This tough, rigid, high strength thermoplastic has a heat deflection temperature of 174°C, and maintains its properties over a wide temperature range. It meets major global health and toxicology requirements, such as NSF Standard 61, WRc and KTW for drinking water applications, and is FDA compliant. UDEL resin grades can be injection molded into complex parts or extruded into forms such as rod, film, sheet, profile and tubing.
APCOM, Inc., a wholly owned subsidiary of A.O. Smith Water Products Co., chose Udel polysulfone for dip tubes used in their Hydro Cannon and Eliminator self-cleaning systems used in many of APCOM's commercial water heaters.
Udel polysulfone dip tubes for self-cleaning commercial water heaters
Udel polysulfone's ability to withstand long-term exposure to hot chlorinated water and its ease of moldability into a complex design were key reasons the polymer was chosen for this application. The Hydro Cannon and Eliminator self-cleaning systems help reduce sediment build-up from settling in the tank by creating a rotating turbulence that keeps sediment particles moving. Commercial water heaters typically operate at 60-82°C, which can accelerate the oxidative effects caused by the presence of residual chlorine and chlorine-based products used to treat potable water. Udel polysulfone is highly resistant to the oxidative effects of chlorine at elevated temperatures, making it a viable material for this aggressive environment. Udel polysulfone's ability to be injection molded into complex parts was an additional important feature because the dip tube design is very complicated to fabricate, due to a complex array of core pulls.
Harsh Environment Resistant Polyphenyl Sulfone (PPSO)
For severe applications such as those requiring repeated sterilization or uncompromising toughness, Radel R polyphenylsulfone (PPSO) stands out. With its high heat deflection temperature of 207°C, it can withstand continuous exposure to heat and still absorb tremendous impact without deflecting or breaking. Plus its chemical resistance surpasses that of most amorphous polymers.
Although traditionally known in industry circles for its uncompromising performance in the reusable medical device arena where it must stand up to repeated high-temperature sterilization, Radel R polyphenylsulfone produced by Solvay Advanced Polymers, LLC, is now being used to protect and house a new generation of thermal imaging cameras manufactured for the firefighting industry.