Differences Between PCTFE and PTFE 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. PTFE (polytetrefluoroethylene) is a soft, low friction fluoropolymer with outstanding chemical resistance and weathering resistance. PTFE is stable at temperatures up to 500°F and it is often used in high temperature environments. PTFE also has excellent electrical insulating properties. 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® PTFE Material Characteristics Broad chemical resistance Moderate compressive strength at cryogenic temperatures High compressive modulus at cryogenic temperatures Poor creep characteristics unless reinforced with fillers Retention of ductility at cryogenic temperatures PTFE Applications: Seals and gaskets Valve and fitting components Pump parts Manifolds Semiconductor equipment Scientific equipment Chemical resistant tubing Bearings and bushings (bearing grades) PTFE Common Brands Rulon®, Fluorosint® Typical properties of PCTFE and PEEK UNITS ASTM TEST PCTFE PTFE Specific gravity D792 2.11 - 2.17 2.15 Water absorption (immersion 24 hours) % D570 0 <0.01 Tensile strength psi D638 4,860 - 5,710 1,500 - 3,000 Elongation % D638 100 - 250 100-200 Izod Impact (notched) ft-lbs/in D256 2.5 - 3.5 3.5 Flexural strength psi D790 9,570 - 10,300 – Flexural modulus psi D790 200,000 - 243,000 72,000 Dielectric strength (short term) v/mil D149 500 400-500 Coefficient of linear thermal expansion in/in/°Fx10-5 D696 3.9 8.9 Coefficient of friction (dynamic) – 0.10 Max continuous service temperature in air °F 380°F 500°F Hardness Scale as noted D785, D2240 Shore D 90 Shore D 55 Values may vary according to brand name. Please ask your Curbell Plastics representative for more specific information about an individual brand.