Knowde Enhanced TDS
Identification & Functionality
- Chemical Family
- Fillers Included
- Polymer Name
- Technologies
- Product Families
- Chemical Composition
Synthetic rubber based on ester/MDI polyurethane.
Features & Benefits
Applications & Uses
- Applications
- Cure Method
- Plastics & Elastomers End Uses
- Plastics & Elastomers Processing Methods
- Product Applications
The excellent balance of properties of Millathane 5004M (Premilled) makes it a perfect choice for various rubber parts including seals, gaskets, O-rings, suction cups, molded electrical parts, dust covers, mounts and bearings for the automotive industry and for many other hydraulic or pneumatic applications.
Properties
- Appearance
- Off-white solid sheets
- Typical Properties
- Product Properties
Vulcanizates based on Millathane 5004M (Premilled) can be produced in hardnesses ranging from approximately 40 to 95 Shore A, and offer very good abrasion resistance, excellent oil resistance,
good low temperature properties and good resistance to gas permeability.
| Value | Units | Test Method / Conditions | |
| Specific Gravity | approx. 1.21 | — | — |
Regulatory & Compliance
- Certifications & Compliance
- Chemical Inventories
Technical Details & Test Data
- Processing Information
- Millathane 5004M (Premilled) is processed by techniques which are common to the rubber industry.
- Compounds can be mixed on open mills or in internal mixers.
- Molded articles can be produced via compression, transfer or injection molding.
- Injection molding Millathane 5004M (Premilled) provides very short cycle times, excellent flow and demolding and shows negligible mold fouling.
- Due to the peroxide vulcanization and its chemical base, Millathane 5004M (Premilled) can not be cured in direct contact with open steam or hot air, and, hence, for applications like hose, its use is limited to inner liners.
- Calendered sheets can be press-cured or Rotocured.
- By its nature, Millathane 5004M (Premilled) is somewhat ‘nervy’ (tough), so compounds may not mill or calender as smoothly as other polymers, like Millathane 66. Millathane 66 can be blended with Millathane 5004M (Premilled) in any proportion to modify processing characteristics or modify properties.
- Compounding Information
- Reinforcing Fillers
- Reinforcing fillers like N330 carbon black or precipitated silica increase the mechanical strength of Millathane 5004M (Premilled)M (Premilled) compounds.
- Fumed silicas such as Wacker HDK N20 or Cabosil M-5 will give somewhat higher reinforcement than precipitated silicas and give translucent cured compounds (depending on other ingredients).
- Clay, talc, and calcium carbonate can also be used as fillers to modify properties and processing, but are less reinforcing than silicas and blacks.
- Silane coupling agents like Silquest RC-1 or Dynasylan 6498, added at about 2% of the mineral filler content, generally improve tear strength, abrasion resistance and compression set.
- Plasticizers
- TP-95 (DBEEA) is a plasticizer that is very compatible with Millathane 5004M (Premilled)M (Premilled), with compounds containing 25 phr and more usually not showing signs of bleeding or incompatibility.
- Other plasticizers such as Mediaplast NB-4 and Benzoflex 9-88SG can also be used to plasticize and soften compounds.
- The antistatic plasticizer Struktol AW-1 can be used to a limited extent, to lower surface resistivity, but may tend to bleed at levels over 10 parts.
- Stabilizers / Antidegradants
- Millathane 5004M (Premilled)M (Premilled), being a polyester polyurethane, is prone to the effect of hydrolysis, where water can attack the polyester linkage of the polymer chain.
- The effect is accelerated by higher temperatures or acidic conditions. The inclusion of a small amount (1-3 phr) of hydrolysis stabilizer such as MillstabTM P will greatly inhibit the effect of hydrolysis.
- Higher levels of stabilizer will generally provide improved or longer protection. Using Premilled Millathane 5004M (Premilled)M (Premilled), which contains 1.5 phr of Millstab P, is a convenient way to include that amount of stabilizer in the compound, and it improves the shelf stability of the polymer as well.
- The chart to the right shows the benefit of 1.5 phr Millstab P to the Florida aging
- of a Millathane 5004M (Premilled)M (Premilled) compound, the compound with Millstab P didn’t soften at all, while the compound withoutMillstab P softened considerably at 3+ years, and fell apart after 5 years.
- 1 phr each of the antioxidants Naugard 445 and Naugard XL-1 can improve (slightly) the heat aging characteristics of Millathane 5004M (Premilled)M (Premilled) compounds.
- Process Aids
Small amounts of process aids are normally used to prevent sticking to processing equipment and to improve flow during molding. - Generally, about 0.2 phr of stearic acid is used along with 0.5-2 phr of another process aid such as Struktol WB222 or Vanfre AP-2.
- Since stearic acid, and acids in general, tend to promote the effect of hydrolysis, it is recommended to keep its level very low.
- A low molecular weight polyethylene like AC617A, added at 1-4 phr, gives a good release for calendering and molding. Process aids are best added at the very beginning of the mix cycle, to prevent sticking to mills and mixing equipment.
- Curing Agents: Peroxides and Coagents
- Typical peroxides used are Di-Cup and Varox DBPH-50, typically used at about 1.5 – 2.5 phr active peroxide. The use of coagents such as triallyl cyanurate (TAC) and trifunctional methacrylates like SR350 (TMTPMA) increase the crosslink density and improve the compression set.
- Liquid methacrylates also function as non-extractable plasticizers. For high hardness
- compounds, blends of trifunctional and difunctional methacrylates (e.g. SR231, DEGDMA) give a good balance of tensile strength, elongation, and good processing.
- Vulcanization Conditions
- Compounds based on Millathane 5004M (Premilled)M (Premilled) are molded at temperatures of 140 - 180°C, depending on the peroxide, dimensions of the part, etc.
- Injection-molded parts with a wall thickness of less than 2 mm can be vulcanized in approximately one minute at 170 - 180°C mold temperature.
- Rubber-covered rollers can be vulcanized in hot air (electric) or steam autoclaves, but it is extremely critical to completely protect the compound from direct contact with steam and to not over-cure the rollers.
- Autoclave temperatures can range from 130 -150°C, with times dependent
- on roller size.
- Abrasion Resistance
- Abrasion resistance is the ability of a surface to resist wearing due to contact with another surface moving with respect to it.
- High resistance to abrasion is important in applications like rollers, belting, and helicopter dust covers.
- The DIN Abrasion Test (ASTM D5963) is one of the most common tests for measuring abrasion resistance.
- It's where a rotating cylindrical sample is passed across a rotating drum of abrasive and the amount of sample volume lost is measured.
- Typical abrasion resistance values for Millathane millable urethane compounds is 50-80 mm³.
- Some compounds can have abrasion resistance values as low as 25 mm³, depending on the polymer, cure system, and formulation.
- Polyurethane rubber provides the highest abrasion resistance of any rubber, synthetic or natural.
- Laboratory tests do not always predict the advantage of Millathane compounds over other rubbers, but field experience often shows a tremendous improvement in product lifetime when millable urethane replaces conventional rubber.
Packaging & Availability
- Packaging Information
Package size/carton: 50 pounds (22.7 kg).
Storage & Handling
- Shelf Life
- 2 years
- Storage Information
Stored under dry and cool conditions.