Rohacell® 70 Polymethacrylimide (PMI) Rigid Foam Sheet

Technical Documents

ROHACELL 71 is a low density grade and a very high strength:weight ratio.

Details

Product Type

Polymer > Polyimides

Applications

Polymers industry
Composites

Producer

Evonik

Supplier

Evonik Iran

Chemical Composition

ROHACELL is manufactured by hot forming of methacrylic acid/methacrylonitrile copolymer sheets. During foaming this copolymer is converted to polymethacrylimide.Information supplied by Emkay Plastics, Ltd

Advantages
  • low density grade
  • very high strength
  • closed-cell rigid expanded plastic material for light weight sandwich construction
  • excellent mechanical properties
  • high dimensional stability under heat
  • solvent resistance
  • particularly at low temperature, a low thermal conductivity
  • highest strength and moduli values
  • highest for any foamed plastic in its density range

Technical data

Quantity Value Unit Comment
Appearance Properties
Appearance White
Physical Properties
Density 0.0753 g/ml ASTM D1622-63
Thermal Properties
Thermal Expansion 35.0 µm/m-°C ASTM D696-70@Temperature 20.0 °C; Linear
Thermal Expansion 30.0 µm/m-°C Temperature -100 °C; Linear@
Thermal Conductivity 0.0300 W/mk ASTM C177-63
Maximum Service Temperature 180 ºC Dimensional stability per DIN 53424; Air
Mechanical Properties
shear strength 1.28 MPa ASTM C273-61
Compressive Strength 1.47 MPa ASTM D1621-64; at Yield
Tensile modulus-MD 90.3 MPa ASTM D638-68
shear modulus 28.4 MPa ASTM C273-61
Flexural strength 2.45 MPa ASTM D790-66; at Yield
Tensile strength 2.74 MPa ASTM D638-68
Elongation at break-MD 4.5 % ASTM D638-68
Chemical Properties
Moisture absorption 1.2 % at Equilibrium; 15% RH
Moisture absorption 2.4 % at Equilibrium; 30% RH
Moisture absorption 3.6 % at Equilibrium; 50% RH
Moisture absorption 4.3 % at Equilibrium; 65% RH
Moisture absorption 15.5 % at Equilibrium; 98% RH
Water absorption 16 % 50days immersion at 20°C; at Saturation
Moisture Expansion <3.0 % 50days immersion at 20°C
Oxirane Oxygen Content 19 - 20 %
Electrical Properties
Dissipation Factor 0.0018 Frequency 1e+10 Hz@
Dielectric Constant 1.13 Frequency 1e+10 Hz@
Dielectric Constant 1.08 Frequency 2.00e+9 Hz@
Dielectric Constant 1.1 Frequency 2.60e+10 Hz@
Dissipation Factor 0.0076 Frequency 2.60e+10 Hz@
Dissipation Factor 0.00030 Frequency 2.00e+9 Hz@
Dissipation Factor 0.00070 Frequency 5.00e+9 Hz@
Surface Resistance 5.50e+12 ohm
Dielectric Constant 1.11 Frequency 5.00e+9 Hz@