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High performance properties of PPA make it ideal for replacing metal |
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Polyphthalamide (PPA) is a high performance polyamide, a semi-crystalline material formed from a diacid and a diamine. However, a portion of the diacid segment is replaced with an aromatic component, terephthalic acid (TPA) or isophthalic acid (IPA), which adds an aromatic ring structure to the polyamide chain, forming a semi-aromatic polyamide. According to ASTM D5336, PPA is defined as "a polyamide in which the residues of TPA or IPA or a combination of the two comprise at least 55 molar percent of the diacid portion of the repeating structural units in the polymer chain."
The addition of an aromatic ring structure to the polyamide imparts many advantages over aliphatic nylons. These consist of elevated glass transition temperatures (Tg), higher melting points, higher deflection temperatures, excellent chemical resistance, and lower absorption of moisture and solvents. These property advantages provide improvements in dimensional stability, solvent and hydrolysis resistance, and also better high temperature mechanical property retention versus standard aliphatic nylons.
PPA can be used with advantages in replacement of metal PPA gives greater product design flexibility and can be used in complex components. PPA has a range of applications as economic alternatives to diecast metals such as aluminum, zinc and brass. In electrical and electronic systems PPA is used as the housing for high temperature electrical connectors, as well as in new lead-free SMT connectors and bushings. These materials, used to replace metals in high temperature automotive applications, also find new use in areas such as thermostat housings, water pumps, charge air coolers, and components in transmissions and engine oil systems. Structural grades such as glass fiber reinforced PPA metal replacement compounds are also debuting in automotive safety and chassis applications.
Applications:
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Chemically Resistant PPA Automotive Coolant
PPA is used in low coolant sensor which can be located in the radiator of truck and marine equipment
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Tire Pressure Monitoring
Tire pressure monitoring has good growth potential. Based on NHTSA's (National Highway Traffic Safety Administration) TREAD mandate, finalized legislation requires that all new light passenger vehicles weighing less than 4500 kgs built or imported into the US to be equipped with tire monitoring systems by the 2009 model year. Weight is an important consideration for parts mounted inside the tire as they must withstand centrifugal forces up to 3,000 times that of gravity. The in-tire sensor weighs just 30 grams |
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Hot Sanitary and Hot Potable Water End Uses
PPA can be used to replace metal use in hot water applications in the sanitary field and in household appliances and can replace aluminum or copper in kettle or coffee machine applications
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Hot Potable Certified PPA Resins for Lead-Free Plumbing
Brass that uses lead for welding can be replaced with PPA
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(Source:Omnexus)
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