Millathane® 5004

A High Performance Millable Polyurethane Rubber

(Formerly known as Vibrathane 5004)

Millathane 5004 is a peroxide curable polyester millable urethane rubber. It has excellent processing characteristics and can be injection molded easily. In addition to excellent abrasion resistance, Millathane 5004 has the highest stress strain values of all peroxide cured polyurethanes. The cured stock has excellent tear strength, excellent low temperature flexibility and resistance to oxygen, ozone, fuels and oils.

Processing

Millathane 5004 is processed by techniques which are common to the rubber industry. Compounds can be mixed on an open mill or in an internal mixer; molded articles can be produced via compression, transfer or injection molding; calendered sheets can be press or rotocured.

Compounding

Millathane 5004 compounds typically contain reinforcing fillers to meet hardness and mechanical strength requirements, but gum compounds, with little or no fillers, have good properties. Reinforcing fillers like silica and small particle carbon black are easily incorporated into Millathane 5004. Millathane 5004 is peroxide-curable only. Typical peroxides used include DiCup 40C and Varox DBPH-50. Carbodiimides can be added at 1-5 parts for improved hydrolysis resistance. A compound with 5 parts of polymeric carbodiimide (Millstab™ P) had excellent retention of properties after 1 year water exposure.

Properties

Vulcanizates based on Millathane 5004 can be produced in hardnesses ranging from 40 to 95 Shore A, and offer very good abrasion resistance, excellent oil resistance, good low temperature properties and good gas permeability.

Typical Polymer Properties

Chemical type Polyester polyurethane
Color White to off-white
Physical form Solid chunks or milled sheets
Packaging*
   Solid chunks: 50 lb. (22.7 kg) carton
   Premilled sheets** 50 lb. (22.7 kg) carton
   *Bale wrap Strippable film (not meant to be incorporated
into the compound)
Odor Faint, characteristic
Specific gravity 1.21
Mooney viscosity,
ML(1+4)/100°C) 		50 – 70
Storage stability 2 years when stored under dry and cool conditions

TYPICAL COMPOUND PROPERTIES

Hardness range 40 – 95 A
Tensile strength Up to 5000 psi, (35 MPa)
Tear strength Up to 450 lb/in (78 kN/m)
Ozone resistance Excellent
Hydrolysis resistance Good/Very good (with hydrolysis stabilizers)
Oil & fuel resistance Very Good/Excellent
Abrasion resistance Excellent
Resilience 30 - 60%

Vulcanization Conditions

Compounds based on Millathane 5004 are vulcanized at temperatures of 150º - 175ºC, depending on the peroxide used, with typical cure times of 5 to 20 minutes for compression molded lab sheets. Injection and transfer molding are also being used commercially with Millathane 5004 compounds.

Formulation Example

(See the Millathane Formulary for other compound examples)

Millathane 5004 100.0
Stearic Acid 0.2
N330 Black 25.0
DBEEA (TP-95) 5.0
Struktol WB222 1.0
Polymeric carbodiimide (Millstab™ P) 2.0
DiCup 40C 5.0
Cured Properties, press cure 16'/160ºC
Hardness, Shore A 70
TSE100*, psi (MPa) 475 (3.3)
TSE200*, psi (MPa) 1090 (7.5)
TSE300*, psi (MPa) 1950 (13.4)
Tensile Strength, psi (MPa) 4100 (28.3)
Elongation at break, % 525
Tear Die C, lb/in (kN/m) 314 (55)

*TSExxx=Tensile Stress at xxx% Elongation

Bashore resilience, % 46
DIN Abrasion, mm³ loss 57
Compression set, 22 hr/70ºC, % 10
Compression set, 22 hr/100ºC, % 36
Compression set, 22 hr/125ºC, % 53
Oven Aging, 70 Hr/100ºC
Hardness change +5
Tensile strength, % change +3
Elongation, % change -5
IRM 903 Oil Aging, 70 Hr/100ºC
Hardness change -3
Tensile strength, % change -30
Elongation, % change -37
Volume change, % 2

Vibrathane is a registered trademark of Chemtura Corp.