Page 216 - Biomedical Engineering and Design Handbook Volume 2, Applications

STERILE MEDICAL DEVICE PACKAGE DEVELOPMENT 195

TABLE 7.2 Properties of Polycarbonate
Polycarbonate
Physical Properties
Density (ρ) 1200–1220 kg/m 3
Abbe number (V) 34.0
Refractive index (n) 1.584–6
Flammability V0–V2
Limiting oxygen index 25–27%
Water absorption—equilibrium (ASTM) 0.16–0.35%
Water absorption—over 24 h 0.1%
Radiation resistance Fair
Ultraviolet (1–380 nm) resistance Fair
Mechanical Properties
Young’s modulus (E) 2–2.4 GPa
Tensile strength (σ ) 55–75 MPa
t
Compressive strength (σ ) >80 MPa
c
Elongation (ε) at break 80–150%
Poisson’s ratio (v) 0.37
Hardness—rockwell M70
Izod impact strength 600–850 J/m
Notch test 20–35 kJ/m 2
Abrasive resistance—ASTM D1044 10–15 mg/1000 cycles
Coefficient of friction (μ) 0.31
Thermal Properties
Melting temperature (T ) 267°C
m
Glass transition temperature (T ) 150°C
g
Heat deflection temperature—10 kN (Vicat B) * 145°C
Heat deflection temperature—0.45 MPa 140°C
Heat deflection temperature—1.8 MPa 128–138°C
Upper working temperature 115–130°C
Lower working temperature –135°C
−6
Linear thermal expansion coefficient (α) 65–70 × 10 /K
Specific heat capacity (c) 1.2–1.3 kJ/kg · K
Thermal conductivity (k) at 23°C 0.19–0.22 W/(m · K)
2
Heat transfer coefficient (h) 0.21 W/(m · K)
Electrical Properties
Dielectric constant (ε ) at 1 MHz 2.9
r
Permittivity (ε) at 1 MHz 2.568 × 10 –11 F/m
Relative permeability (μ ) at 1 MHz 0.866
r
Permeability (μ) at 1 MHz 1.089 μN/A 2
Dielectric strength 15–67 kV/mm
Dissipation factor at 1 MHz 0.01
15
Surface resistivity 10 Ω/sq
12
14
Volume resistivity (ρ) 10 –10 Ω · m
*ASTM D1525-07 Standard Test Method for Vicat Softening Temperature of Plastics, ASTM International, West
Conshohocken, PA, 2007, DOI: 10.1520/D 1525–07.
Source: Wikipedia (http://en.wikipedia.org/wiki/Polycarbonate).