FAQ | POLYUREA CURATIVES

Gantrade’s GCLink P-series is a family of specialty oligomeric polyether diamine curatives based on the p-aminobenzoate ester. In polyureas, they show excellent dynamic properties, resiliency, high tensile strength, and abrasion resistance. 

These aromatic diamine-terminated polyethers are designed to be formulated with monomeric isocyanates.

Because of their reduced amine reactivity and liquid or low melting nature, these oligomeric diamines enable significant processing advantages with MDI and TDI systems, including a processing window at lower temperatures and lower shrink values due to lower cure temperatures.  Their built-in flexibility and toughness, water, chemical and abrasion resistance, and excellent dynamic properties provide polyureas with superior performance characteristics.  In addition, our oligomeric diamines function as epoxy hardeners. 

What are the key performance attributes of the GCLink P-series curatives in polyurea elastomers?

• Low reactivity and a wide processing latitude in MDI systems
  
• Pot life of 20-30 minutes at 25°C; 5-10 minutes at 60°C
  
• Reduced heat build-up and low shrink values in the cure of large parts
  
• Excellent dynamic properties, resiliency and rebound properties, good tensile and tear strengths, and excellent Tabor abrasion resistance
  
• Hydrolysis and chemical resistance
  
• Superior flexibility and toughness at low temperatures  
  
• Maintenance of properties at high temperatures
  
• Excellent adhesion to a wide variety of surfaces
  
• Low toxicity

Typical applications for the GCLink P-series include cast elastomers, protective coatings, energy absorption,  adhesives, sealants, and polyurea spray systems. The GCLink P-series family of diamines are the preferred curatives in the design of polyurea ballistic armor and blast mitigation coatings.

How do the various GCLink P-series products differ?

Gantrade’s GCLink P-series is a family of diamines based on the p-aminobenzoate esters of varying molecular weight grades of PTMEG: 

• PTMEG 650
  
• PTMEG 1000
  
• PTMEG 2000

GCLink 740 is a monomeric diamine based on the p-aminobenzoate ester of 1,3-propanediol.  The variant GCLink 740M is FDA compliant for direct contact with dry foods.   

With MDIs, including the carbodiimide-modified MDIs, formulators may customize polyurea properties by varying the diamine molecular weight, stoichiometry (NCO index), and isocyanate chemistry.  Durometer values can be achieved from below 80A to above 60D.

What range of polyurea properties can be achieved with the P-series grades of diamines?

The data below compares the properties of p-aminobenzoate-capped PTMEG 650, 1000, and 2000 polyureas cured with a multifunctional carbodiimide-modified MDI, MM103.  These systems exhibit a unique combination of high tensile strengths, elongations, and tear resistance over a wide range of hardness.

What are the sales specifications for the GCLink P-series diamines?

The sales specifications for the GCLink P-series diamines are provided below.  Total Equivalent Weight should be used in calculating stoichiometries, since mono-hydroxy fractions exist.

For more information on the GCLink family of curatives, contact Gantrade today. Gantrade provides experienced technical support, working with our customers to solve problems and to develop unique products.