Gantrade’s P-1000 and P-2000 are oligomeric diamine curatives based on the p-aminobenzoate ester of PTMEG 1000 and PTMEG 2000, respectively. The Gantrade P-1000 is similar to Versaink® P-1000. The P-2000 is a new material, developed for applications where a lower Durometer is required. A diamine based on the p-aminobenzoate of PTMEG 650 is also available from Gantrade Corporation.
Because of their reduced reactivity and low melting nature, these oligomeric diamines can be used in low temperature cures with either TDI and MDI systems. These characteristics afford significant processing advantages, including a lower temperature processing window, lower mixing temperature requirements, better maintenance of accurate mix ratios and lower shrink values due to lower cure temperatures. This facilitates mixing, hand-batching, casting, coating and molding operations. They can also be used as co-curatives and impact-flexibility modifiers for glycidyl type epoxy resins.
The chemical structure of Gantrade’s P-1000 and P-2000 is shown below. The n value for the PTMEG segment is 13-14 for the P-1000 and 27-28 for the P-2000. The molecular weights are 1238 and 2238, respectively. The molecular weight distribution of these diamines range from 2.2 to 2.9.
The general attributes of the P-1000 and P-2000 curatives in polyurea elastomers include the following:
- Low reactivity and a wide processing latitude with MDI prepolymers having NCO contents of 9-30 %
- pot lives of 20-30 minutes at 25° C with high NCO content MDI prepolymers.
- pot lives of 5-10 minutes at 60° C
- P-1000 is a liquid at room temperature; P-2000 is a low melting wax.
- Contribute the benefits of PTMEG soft-segments including excellent resiliency/rebound properties, good tensile and tear strengths, toughness and abrasion resistance, especially impingement abrasion resistance..
- Hydrolysis and chemical resistance.
- Good flexibility and impact resistance at low temperatures.
- Shore A Durometer values can range from 75-95 for P-1000 and 60-80 for P-2000 with MDI prepolymers, depending on the % NCO levels.
- A low order of toxicity.
Typical sales specifications for Gantrade’s P-1000 and P-2000 are provided below.
Sales Specifications for Oligomeric Diamine
Performance properties for an MDI-ether based polyurea elastomer produced from P-1000 are shown below.
Performance Data in Polyureas
Property characterizations on the polyurea resulting from P-1000 and Isonate® 143L, a higher functionality, carbodiimide modified MDI, have been well studied and reported in the literature. References are available from Gantrade Corporation.
As low melting curatives, both P-1000 and P-2000 can be mixed with liquid TDI and MDI prepolymers at lower temperatures and cast into molds. These systems are generally post-cured for 16 hours at 80° C. Room temperature cures generally require two weeks to achieve complete cure. The glass transition temperatures of polyureas cured with both P-1000 and P-2000 vary based on factors such as the stoichiometry ratios and % NCO. But the Tg’s of the soft segments are generally below minus (-) 60° C and for the polyureas, minus (-) 45-55° C, when measured by thermal analysis.
Depicted below is the chemical reaction and polyurea structure when reacted with MDI. This provides a representation of the hard block and soft-block segments of a polyurea based on P-1000. Phase separation occurs because of the chemical dissimilarity of the soft and hard phases, and hydrogen bonding, resulting in a hard phase that is dispersed in the soft PTMEG matrix. Additionally, the hard phase can reinforce the soft matrix to create a pseudo-crosslinked backbone. This enhances the mechanical properties of the polyurea.
The application areas include hot and cold cast operations, coatings, adhesives, sealants, ballistic armor, polyurea spray systems and field repair polyurea and epoxy kits. These diamines are ideal for curing large parts where heat build-up is an issue with other higher reactivity curatives.
Gantrade offers the P-1000 and P-2000 in galvanized iron or plastic drums, with a net eight of 20 Kg or 50 Kg. Sample quantities are generally 1 Kg. in size.
Gantrade recommends a thorough review of our SDS prior to handling these curatives, and observance of the correct safety precautions and handling requirements. The diamines should be stored in a well ventilated and dry location. Be sure to keep these products away from sunlight.