Polymers

Ethylene propylene diene monomer rubber — THE outdoor/weather elastomer. Saturated backbone gives outstanding ozone, UV, and weathering resistance. Excellent resistance to steam, hot water, and polar solvents. NOT resistant to oils/fuels (opposite of NBR). Good electrical insulation. ρ 0.85-1.3 (lightest common rubber). Used for automotive door/window seals, roofing membranes, radiator hoses, HVAC gaskets, and pond liners.

Fluoroelastomer — THE high-temperature and chemical-resistant rubber. Outstanding resistance to oils, fuels, acids, and solvents at temperatures up to 200°C (short-term 230°C). Fluorine content (64-70%) determines chemical resistance. Trade names: Viton (Chemours), Tecnoflon (Solvay), Dai-El (Daikin). 5-10x more expensive than NBR. Used for aerospace fuel seals, chemical process seals, automotive fuel injector O-rings, semiconductor processing, and any seal exposed to aggressive chemicals at high temperature.

Nitrile butadiene rubber (Buna-N) — THE oil and fuel resistant elastomer. ACN content (18-50%) determines the oil resistance vs low-temp flexibility tradeoff. Higher ACN = better oil resistance but stiffer at low temp. The most widely used seal material worldwide. Used for O-rings, fuel hoses, gaskets, hydraulic seals, oil seals, and nitrile gloves. Not suitable for ozone, UV, or polar solvents (ketones, esters). HNBR variant for higher heat resistance.

Two-component platinum-catalyzed liquid silicone rubber processed by injection molding. Cures at 120–200°C in seconds (fast cycles). Outstanding temperature range -55°C to +200°C (intermittent 300°C). Biocompatible (USP Class VI, ISO 10993), optically clear grades available, excellent electrical insulation. Shore hardness 10A to 70A. Trade names: Silopren (Momentive), Elastosil (Wacker), Silastic (Dow). Used for baby bottle nipples, medical device seals, automotive gaskets, LED optics, baking molds, wearable devices and overmolded electronics.

Silicone rubber (VMQ = Vinyl Methyl Polysiloxane) — THE extreme-temperature elastomer. Usable from -60°C to +230°C continuous (short-term +300°C). Excellent UV/ozone/weathering resistance. Biocompatible (FDA, USP Class VI). Low compression set. Electrically insulating. Lower tensile/tear strength than organic rubbers. Used for seals/gaskets, medical tubing/implants, food-grade components, baby products, automotive ignition boots, and LED/lighting encapsulation.

Styrene-ethylene-butylene-styrene (SEBS) based thermoplastic elastomer — the largest and most versatile TPE family. Hardness adjustable from Shore 0A to 100A through compounding with PP, oil, and fillers. Excellent UV/ozone/aging resistance (superior to SBS). Soft, comfortable touch. Non-toxic, meets EN 71 + REACH + FDA. Bonds well to PP and PE in 2K injection molding. Used for soft-touch grips, seals, gaskets, overmolded handles, baby products, medical tubing, cable jacketing, and shoe soles. Not oil-resistant.

Dynamically vulcanized thermoplastic elastomer — crosslinked EPDM rubber particles dispersed in a PP matrix. Combines the elastic recovery of vulcanized rubber with the processability of thermoplastics (injection moldable, extrudable, recyclable). Shore hardness range 40A to 50D. Compression set resistance far superior to TPE-S (SBS/SEBS). Trade names: Santoprene (Celanese), Sarlink (Teknor Apex), Forprene (So.F.Ter). Used for automotive seals/weatherstrips, wire & cable jacketing, industrial hoses, consumer grips and overmolded soft-touch components. Service temp -40°C to +135°C.

Thermoplastic polyurethane elastomer — bridges the gap between rubber and rigid plastics. Exceptional abrasion resistance, high elongation (300-700%), and good oil/grease resistance. Available in wide hardness range (60 Shore A to 74 Shore D). Ester-based: better oil resistance. Ether-based: better hydrolysis/microbial resistance. Major trade names: Elastollan (BASF), Desmopan/Texin (Covestro), Estane (Lubrizol). Used for seals, hoses, cable jackets, shoe soles, phone cases, wheels/rollers, and 3D printing filament.