eMKay Plastics Ltd | ROHACELL 71 Polymethacrylimide (PMI) Rigid Foam Sheet

Tech Data- ROHACELL 71 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 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 20ƒC.
Moisture Expansion	Max 3 %	Max 3 %	50 days immersion at 20ƒC.
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 -100ƒC	30 µm/m-ƒC	16.7 µin/in-ƒF
CTE, linear 20ƒC	35 µm/m-ƒC	19.4 µin/in-ƒF	ASTM D 696-70
Thermal Conductivity	0.03 W/m-K	0.208 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

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Tel: +44 (0) 1603 746 000 | Fax: +44 (0) 1603 746 001 | Email: info@emkayplastics.co.uk

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Material Notes:

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 20ƒC.

Moisture Expansion

Max 3 %

Max 3 %

50 days immersion at 20ƒC.

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