preface to fifteenth edition

TABLE 10.3 Properties ofNatural and Synthetic Rubbers
Rubber
Specific
gravity
Durometer
hardness
(or Shore)
Ultimate
elongation
% (23C)
Tensile
strength,
lb · in 2 (23C)
Service
temperature, C
Minimum Maximum
Gutta percha (hard rubber) 1.2–1.95 (65–95) 3–8 4000–10,000 104
Natural rubber (NR) 0.93 20–100 750–850 3000–4500 56 82
Chlorosulfonated polyethylene 1.10 50–95 100–500 500–3000 54 121
Epichlorohydrin 1.27 60–90 100–400 1000–2500 46 121
Fluoroelastomers 1.4–1.95 60–90 100–350 2000–3000 40 232
Isobutene-isoprene rubber (IIR) [also known as
government rubber I(GR-I)] 0.91 (40–70) 750–950 2300–3000 121
Nitrile rubber (butadiene-acrylonitrile rubber) (also
known as Buna N and NBR) 1.00 30–100 100–600 500–4000 54 121
Polyacrylate 1.10 40–100 100–400 1000–2200 18 149
Polybutadiene rubber (BR) 0.93 30–100 100–700 2500–3000 62 79–100
Polychloroprene (neoprene) 1.23 20–90 800–1000 2000–3500 54 121
Poly(ethylene-propylene-diene) (EPDM) 0.85 30–100 100–300 1000–3000 40 149
Polyisobutylene (butyl rubber) 0.92 30–100 100–700 1000–3000 54 100
Polyisoprene 0.94 20–100 100–750 2000–3000 54 79–82
Polysulfide (Thiokol ST) 1.34 20–80 100–400 700–1250 54 82–100
Poly(vinyl chloride) (Koroseal) 1.32 (80–90) 2400–3000 71
Silicone, high-temperature 700–800 316
Silicone 0.98 20–95 50–800 500–1500 84 232
Styrene-butadiene rubber (SBR) (also known as Buna S) 0.94 40–100 400–600 1600–3700 60 107
Urethane 0.85 62–95 100–700 1000–8000 54 100
10.63