Differences Between PCTFE and PEEK PCTFE is a fluoropolymer material with outstanding strength, stiffness, and dimensional stability. It has excellent chemical and radiation resistance and good flammability characteristics. PCTFE has a broad temperature range, good resistance to cold flow, and it has the lowest coefficient of thermal expansion of any unfilled fluoropolymer. PEEK (polyetheretherketone) is a high-performance engineering plastic with outstanding resistance to harsh chemicals, and excellent mechanical strength and dimensional stability. PEEK has a broad operating temperature range, offers hydrolysis resistance to steam, and maintains stiffness at high temperatures. PCTFE Material Characteristics Broad chemical resistance High purity High compressive strength Retention of ductility at cryogenic temperatures Good resistance to creep (cold-flow) for a fluoropolymer Relatively stable thermal expansion coefficient across temperature extremes Very low gas permeability (excellent barrier properties) Excellent flammability characteristics and oxygen compatibility Good radiation resistance PCTFE Applications: Chemical processing components Valve seats, seals, and gaskets Chromatography columns Liquid oxygen and liquid nitrogen valve linings Moisture barriers PEEK Common Brands Neoflon®, Kel-F®, Aclon® PEEK Material Characteristics Broad chemical resistance Maximum service temperatures approaching 500°F High strength, stiffness, and creep resistance to deformation at high temperatures Excellent mechanical properties down to -85°F Retention of ductility at cold temperatures Excellent dimensional stability PEEK Applications: Semiconductor machinery components Aerospace parts Subsea parts Down hole electrical connectors Medical and pharmaceutical instruments Food processing machinery components Compressor, pump, and valve components Bushings, bearings, seals, and back-up rings Sterilizable by autoclave, dry heat, Et0, gamma irradiation, and electron beam PEEK Common Brands TECAPEEK®, SustaPEEK, Ketron® Typical properties of PCTFE and PEEK UNITS ASTM TEST PCTFE PEEK Specific gravity D792 2.11 - 2.17 1.32 Water absorption (immersion 24 hours) % D570 0 0.50 Tensile strength psi D638 4,860 - 5,710 14,000 Elongation % D638 100 - 250 60 Izod Impact (notched) ft-lbs/in D256 2.5 - 3.5 1.6 Flexural strength psi D790 9,570 - 10,300 24,600 Flexural modulus psi D790 200,000 - 243,000 590,000 Dielectric strength (short term) v/mil D149 500 480 Coefficient of linear thermal expansion in/in/°Fx10-5 D696 3.9 2.6 Coefficient of friction (dynamic) – 0.25 Max continuous service temperature in air °F 380°F 480°F Hardness Scale as noted D785, D2240 Shore D 90 M105, R126, Shore D 85 Values may vary according to brand name. Please ask your Curbell Plastics representative for more specific information about an individual brand.