Polycarbonate

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).

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
FlammabilityV0-V2
Limiting oxygen index25–27%
Water absorptionEquilibrium (ASTM)0.16–0.35%
Water absorption—over 24 hours0.1%
Radiation resistanceFair
Ultraviolet (1–380 nm) resistanceFair
Mechanical properties
Young's modulus (E)2.0–2.4 GPa
Tensile strengtht)55–75 MPa
Elongation (ε) at break80–150%
Compressive strength (σc)>80 MPa
Poisson's ratio (ν)0.37
HardnessRockwellM70
Izod impact strength600–850 J/m
Notch test20–35 kJ/m2
Abrasive resistance ASTM D104410–15 mg/1000 cycles
Coefficient of friction (μ)0.31
Speed of sound2270 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 N145–150 °C (293–302 °F)[1]
Upper working temperature115–130 °C (239–266 °F)
Lower working temperature−40 °C (−40 °F)[2]
Thermal conductivity (k) at 23 °C0.19–0.22 W/(m·K)
Thermal diffusivity (a) at 25 °C0.144 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 MHz2.9
Permittivity (ε)2.568 × 10−11 F/m
Relative permeability (μr) at 1 MHz0.866(2)
Permeability (μ) at 1 MHz1.089(2) μN/A2
Dissipation factor at 1 MHz0.01
Surface resistivity1015 Ω/sq
Volume resistivity (ρ)1012–1014 Ω·m
Chemical resistance
AcidsconcentratedPoor
AcidsdiluteGood
AlcoholsGood
AlkalisGood-Poor
Aromatic hydrocarbonsPoor
Greases and oilsGood-fair
Halogenated hydrocarbonsGood-poor
HalogensPoor
KetonesPoor
Gas permeation at 20 °C
Nitrogen10–25 cm3·mm/(m2·day·Bar)
Oxygen70–130 cm3·mm/(m2·day·Bar)
Carbon dioxide400–800 cm3·mm/(m2·day·Bar)
Water vapour1–2 g·mm/(m2·day) @ 85%–0% RH gradient
Economics
Price2.6–2.8 €/kg[4]