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MK Plastics Technical Data

Subcategory: Composite Core Material; Polymer; Polymethacrylimide; Thermoset

Material Notes:
ROHACELL 31 is the lowest 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 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.

 

Rohacell 31 IG-F

Properties Metric English Comments
Physical Properties
Density 0.032 g/cc 0.00116 lb/in_ ASTM D 1622-63
Water Absorption 19.5% 19.5% Equilibrium at 98% RH
Moisture Absorption at Equilibrium 1.5% 1.5% 15% RH
Moisture Absorption at Equilibrium 2.9% 2.9% 30% RH
Moisture Absorption at Equilibrium 4.7% 4.7%  50% RH
Moisture Absorption at Equilibrium 6% 6% 65% RH
Water Absorption at Saturation 13% 13%  Volume %; 50 days immersion at 20fC.
Moisture Expansion Max 1% Max 1% 50 days immersion at 20fC.
Mechanical Properties
Tensile Strength, Ultimate 0.979 MPa 142 psi ASTM D 638-68
Elongation @ break 3.5% 3.5% ASTM D 638-68
Modulus of Elasticity 0.0353 GPa 5.12 ksi ASTM D 638-68
Flexural Yield Strength 0.786 MPa 114 psi ASTM D 790-66
Compressive Yield Strength 0.393 mpA 57 PSI ASTM D 790-66
Shear Modulus 0.0128 1.85 ksi ASTM C 273-61
Shear Modulus 0.0137 1.99ksi ASTM D 2236-69
Shear Strength 0.393 MPa 57 psi ASTM C 273-61
Electrical Properties
Dielectric Constant 1.05 1.05  5.0 GHz
Dielectric Constant 1.05 1.05 10.0 GHz
Dielectric Constant 1.06 1.06 26.0 GHz
Dielectric Constant 1.08 1.08 2.0 GHz
Dissipation Factor 0.0001 0.0001 2.0 GHz
Dissipation Factor 0.0004 0.0004 5.0 GHz
Dissipation Factor 0.0008 0.0008 10.0 GHz
Dissipation Factor 0.0034 0.0034 26.0 GHz
Surface Resistance 2E+13 ohm 2E+13 ohm  
Thermal Properties
CTE, Linear -100fC 25 µm/m-ƒC 13.9 µin/in-ƒF  
CTE, Linear 20fC 37 µm/m-ƒC 20.6 µin/in-ƒF ASTM D 696-70
Thermal Conductivity 0.031 W/m-K 0.215 BTU-in/hr-ft_-ƒF ASTM C 177-63
Maximum Service Temperature,
Air
180 ƒC 356 ƒF Dimensional stability per DIN 53424
Oxygen Index 19 - 20% 19 - 20%  
Descriptive Properties
Colour White