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Millathane® 76
A general purpose polyester millable urethane
rubber for
abrasion resistant applications.
Download MSDS and data sheet
Millathane 76 is a polyester millable urethane having improved processing
properties over a wide Mooney viscosity range. Compounds can be compression,
transfer, or injection molded in a hardness range of 30 to 90 Shore A.
Millathane 76 can be vulcanized by either sulfur or peroxide cure systems.
Millathane 76 has excellent damping properties useful in vibration control
for many automotive applications. Many o-rings, seals and gaskets are made
from Millathane 76 because of its excellent oil and fuel resistance.
Millathane 76 is comparable to nitrile in oil and fuel resistance, but has
better low temperature properties and excellent ozone resistance.
Millathane 76 can be used to replace conventional
elastomers such as natural rubber, nitrile, and EPDM. Millathane 76
possesses excellent abrasion resistance combined with toughness, low
temperature flexibility, ozone resistance, good damping, high tear strength
and good stress relaxation properties.
Such a combination of properties makes Millathane 76 a suitable choice in
many applications such as bushings, small copier rolls and bumpers, o-rings,
hydraulic seals, belts, solid tires, and many other high performance
polyurethane parts.
| TYPICAL POLYMER PROPERTIES |
| Chemical type |
Polyester polyurethane |
| Color |
Light to dark amber |
| Physical form |
Solid
bale (or milled sheets*) |
| Packaging |
|
|
Solid bale: |
45 lb (20.4 kg) carton |
|
Premilled sheets* |
50 lb. (22.7 kg) carton |
| Odor |
Faint, characteristic |
| Specific gravity |
1.22 |
Mooney viscosity,
ML(1+4)/100°C) |
25 – 70 (35±10 typical) |
| Storage stability |
2
years under dry and cool conditions
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| *milled sheets contain 1.5 phr of
polymeric carbodiimide (Millstab™ P) for improved hydrolysis resistance |
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| TYPICAL COMPOUND
PROPERTIES |
| Hardness range |
25 –
90 A |
| Tensile strength |
Up to
5000+ psi, (35+ MPa) |
| Tear
strength |
Up to 400 lb/in (70 kN/m) |
| Compression set |
Very good (peroxide cure) |
| Heat aging 100º C (212º F) |
Good (sulfur cure)
Very good (peroxide cure) |
| Ozone
resistance |
Excellent |
| Hydrolysis resistance |
Fair-Good |
| Oil & fuel resistance |
Excellent |
| Low temperature |
- 40º C (-40º F) brittle point |
| Weathering |
Good |
| Abrasion resistance |
Excellent |
| Resilience |
10 - 20% |
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TYPICAL END USES |
|
| Printing rollers |
Industrial solid tires |
| Drive belts |
Vibration isolators |
| O-rings |
Suspension bushings |
| Specialty hose |
Conveyor belting |
| Can tester pads |
Copier rolls |
| Grease seals |
Dust covers |
| Packing gaskets |
Chute linings |
| Suction cups |
Hydraulic seals |
| Seals |
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PROCESSING
Millathane 76 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 76 compounds typically contain reinforcing fillers to achieve
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 76. It is sulfur or peroxide-curable.
The best sulfur cure system is a combination of MBTS, MBT,
Thanecure® ZM,
and sulfur, with zinc stearate as an activator/process aid.
Any of the typical peroxides can be used for peroxide curing,
including dicumyl peroxide and DBPH. Coagents, such as TMPTMA (SR-350, from
Sartomer), are commonly used along with peroxides to modify hardness,
processing and other properties.
VULCANIZATION CONDITIONS
Compounds based on Millathane 76 are vulcanized at temperatures of 150º -
175ºC, depending on the cure system used, with typical cure times of 5 to 20
minutes for compression molded lab sheets.
FORMULATION EXAMPLE
| Millathane 76 |
100.0 |
| Zinc Stearate
|
0.5 |
| N330 Black |
30.0 |
| MBTS |
4.0 |
| MBT |
2.0 |
|
Thanecure® ZM |
1.0 |
| Sulfur |
1.5 |
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| Cured Properties, press cure 10'/155ºC |
| Hardness, Shore A |
70 |
| 100% Modulus, MPa |
3.7 |
| 200% Modulus, MPa |
8.5 |
| 300% Modulus, MPa |
14.9 |
| Tensile Strength, MPa |
32.8 |
| Elongation at break, % |
539 |
| Tear Die C, kN/m |
61 |
| Brittle Point, ºC |
-35 |
| Bashore Resilience, % |
14 |
| Compression Set, 22 hr/70ºC, % |
36 |
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