|
ROHACELLﾆ 70 Polymethacrylimide (PMI) Rigid
Foam Sheet
|
|
|
| Subcategory:
Composite Core Material; Polymer; Polymethacrylimide; Thermoset |
| Material
Notes:
|
|
ROHACELL 71
is a low density grade and a very high strength:weight ratio.
|
|
General ROHACELL
Information: ROHACELL is a closed-cell rigid expanded plastic material
for lightweight sandwich construction. It has excellent mechanical
properties, high dimensional stability under heat, solvent resistance
and, particularly at low temperature, a low thermal conductivity.
The strength and moduli values are the highest are the highest for
any foamed plastic in its density range. ROHACELL is manufactured
by hot forming of methacrylic acid/methacrylonitrile copolymer sheets.
During foaming this copolymer is converted to polymethacrylimide.
|
|
|
|
Physical Properties
|
Metric
|
English
|
Comments
|
|
|
|
|
|
|
Density
|
0.0753 g/cc
|
0.00272 lb/in_
|
ASTM D 1622-63
|
|
Water Absorption
|
15.5 %
|
15.5 %
|
Equilibrium
at 98% RH
|
|
Moisture Absorption
at Equilibrium
|
1.2 %
|
1.2 %
|
15% RH
|
|
Moisture Absorption
at Equilibrium
|
2.4 %
|
2.4 %
|
30% RH
|
|
Moisture Absorption
at Equilibrium
|
3.6 %
|
3.6 %
|
50% RH
|
|
Moisture Absorption
at Equilibrium
|
4.3 %
|
4.3 %
|
65% RH
|
|
Water Absorption
at Saturation
|
16 %
|
16 %
|
Volume %;
50 days immersion at 20イ.
|
|
Moisture Expansion
|
Max 3 %
|
Max 3 %
|
50 days immersion
at 20イ.
|
|
|
|
|
|
|
Mechanical
Properties
|
|
|
|
|
|
|
|
|
|
Tensile Strength,
Ultimate
|
2.74 MPa
|
398 psi
|
ASTM D 638-68
|
|
Elongation
@ break
|
4.5 %
|
4.5 %
|
ASTM D 638-68
|
|
Modulus of
Elasticity
|
0.0903 GPa
|
13.1 ksi
|
ASTM D 638-68
|
|
Flexural Yield
Strength
|
2.45 MPa
|
356 psi
|
ASTM D 790-66
|
|
Compressive
Yield Strength
|
1.47 MPa
|
213 psi
|
ASTM D 1621-64
|
|
Shear Modulus
|
0.0284 GPa
|
4.12 ksi
|
ASTM C 273-61
|
|
Shear Modulus
|
0.0294 GPa
|
4.27 ksi
|
ASTM D 2236-69
|
|
Shear Strength
|
1.28 MPa
|
185 psi
|
ASTM C 273-61
|
|
|
|
|
|
|
Electrical
Properties
|
|
|
|
|
|
|
|
|
|
Dielectric
Constant
|
1.08
|
1.08
|
2.0 GHz
|
|
Dielectric
Constant
|
1.1
|
1.1
|
26.0 GHz
|
|
Dielectric
Constant
|
1.11
|
1.11
|
5.0 GHz
|
|
Dielectric
Constant
|
1.13
|
1.13
|
10.0 GHz
|
|
Dissipation
Factor
|
0.0003
|
0.0003
|
2.0 GHz
|
|
Dissipation
Factor
|
0.0007
|
0.0007
|
5.0 GHz
|
|
Dissipation
Factor
|
0.0018
|
0.0018
|
10.0 GHz
|
|
Dissipation
Factor
|
0.0076
|
0.0076
|
26.0 GHz
|
|
Surface Resistance
|
5.5E+12 ohm
|
5.5E+12 ohm
|
|
|
|
|
|
|
|
Thermal Properties
|
|
|
|
|
|
|
|
|
|
CTE, linear
-100イ
|
30 ｵm/m-イ
|
16.7 ｵin/in-ェ
|
|
|
CTE, linear
20イ
|
35 ｵm/m-イ
|
19.4 ｵin/in-ェ
|
ASTM D 696-70
|
|
Thermal Conductivity
|
0.03 W/m-K
|
0.208 BTU-in/hr-ft_-ェ
|
ASTM C 177-63
|
|
Maximum Service
Temperature, Air
|
180 イ
|
356 ェ
|
Dimensional
stability per DIN 53424
|
|
Oxygen Index
|
19 - 20 %
|
19 - 20 %
|
|
|
|
|
|
|
|
Descriptive
Properties
|
|
|
|
|
|
|
|
|
|
Color
|
White
|
|
|
|
|
|
|
|