Polycarbonate

Polycarbonate
Repeating chemical structure unit of Polycarbonate made from bisphenol A Transmission spectrum of polycarbonate
Physical properties
Density (ρ)	1.20–1.22 g/cm3
Abbe number (V)	34.0
Refractive index (n)	1.584–1.586
Flammability	HB-V2
Limiting oxygen index	25–29%
Water absorption—Equilibrium (ASTM)	0.16–0.35%
Water absorption—over 24 hours	0.1%
Ultraviolet (1–380 nm) resistance	Fair
Mechanical properties
Young's modulus (E)	2.0–2.4 GPa
Tensile strength (σt)	55–75 MPa
Elongation (ε) at break	80–150%
Compressive strength (σc)	>80 MPa
Poisson's ratio (ν)	0.37
Hardness—Rockwell	M70
Izod impact strength	600–850 J/m
Notch test	20–35 kJ/m2
Abrasive resistance ASTM D1044	10–15 mg/1000 cycles
Coefficient of friction (μ)	0.31
Speed of sound	2270 m/s
Thermal properties
Glass transition temperature (Tg)	147 °C (297 °F)
Heat deflection temperature	0.45 MPa: 140 °C (284 °F) 1.8 MPa: 128–138 °C (262–280 °F)
Vicat softening point at 50 N	145–150 °C (293–302 °F)[1]
Upper working temperature	115–130 °C (239–266 °F)
Lower working temperature	−40 °C (−40 °F)[2]
Thermal conductivity (k) at 23 °C	0.19–0.22 W/(m·K)
Thermal diffusivity (a) at 25 °C	0.144 mm²/s[3]
Linear thermal expansion coefficient (α)	65–70 × 10−6/K
Specific heat capacity (c)	1.2–1.3 kJ/(kg·K)
Electrical properties
Dielectric constant (εr) at 1 MHz	2.9
Permittivity (ε)	2.568 × 10−11 F/m
Relative permeability (μr) at 1 MHz	0.866(2)
Permeability (μ) at 1 MHz	1.089(2) μN/A2
Dissipation factor at 1 MHz	0.01
Surface resistivity	1015 Ω/sq
Volume resistivity (ρ)	1012–1014 Ω·m
Chemical resistance
Acids—concentrated	Poor
Acids—dilute	Good
Alcohols	Good
Alkalis	Good-Poor
Aromatic hydrocarbons	Poor
Greases and oils	Good-fair
Halogenated hydrocarbons	Good-poor
Halogens	Poor
Ketones	Poor
Gas permeation at 20 °C
Nitrogen	10–25 cm3·mm/(m2·day·Bar)
Oxygen	70–130 cm3·mm/(m2·day·Bar)
Carbon dioxide	400–800 cm3·mm/(m2·day·Bar)
Water vapour	1–2 g·mm/(m2·day) @ 85%–0% RH gradient
Economics
Price	2.6–2.8 €/kg[4]

Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many applications. Polycarbonates do not have a unique resin identification code (RIC) and are identified as "Other", 7 on the RIC list. Products made from polycarbonate can contain the precursor monomer bisphenol A (BPA).