Which curatives and chain extender families are used with MDI and TDI based systems?

Diamines are the most common curatives for TDI systems, where diols and polyols are preferred with MDI systems. Hybrids of amine curatives and polyols are also employed with both TDI and MDI systems. In addition, Gantrade offers lower reactivity diamines which can be used with MDI systems. Examples include the p-aminobenzoate ester of PTMEG 1000 and many of our custom formulated curatives.

What curatives and chain extenders are offered by Gantrade Corporation?

Gantrade offers a broad line of polyols, diols, aromatic amines and custom formulated curatives. To support our customers, Gantrade has developed a broad product line and technical service support through our Polyurethane Laboratory in Charlotte, NC. We are particularly strong in the hot cast elastomers sector. A summary of some key products offered by Gantrade is presented below:

Aromatic Amine Products 

MOCA

Solid at room temperature
MOCA is the most common curative for TDI based prepolymers. It offers good physical properties at a relatively low cost.

MCDEA

Solid at room temperature
Low color curative with faster reaction than MOCA but yielding superior mechanical and dynamic properties.

DMTDA

Liquid at room temperature
A liquid aromatic chain extender, with a slower cure profile vs. DETDA. It offers outstanding mechanical properties and chemical resistance

DETDA

Liquid at room temperature
A liquid aromatic chain extender, curing at ambient temperature. It offers outstanding mechanical and chemical resistance at a low level of toxicity.

P-1000

Waxy Solid at room temperature
Non-hazardous curative for use with MDI or TDI prepolymers. Can be used to produce room temperature cured systems or to reduce hardness of hot cure elastomers.

MBOEA

Liquid at room temperature
Can be used to replace solid diamines yielding properties harder material than MOCA.

MBA-NaCl

Liquid at room temperature
Blocked aromatic diamine curative which offers very long gel time. Curing requires heating system to 120°C.

Aromatic Amine Products

Physical Form at Room Temperature

Product Features

MOCA -

4,4’-Methylene-bis(ortho-chloroaniline)

Solid

MOCA is a unique curative and chain extender for isocyanate pre-polymers, and epoxy resins, characterized by extended gel times at high temperatures. Polyurea semi-rigid foams and solid hot cast elastomers produced using MOCA exhibit durability, resiliency, excellent abrasion resistance, tensile, cut, tear, compressive strength properties, and impact strength, etc.

Gantrade has 3 grades of MOCA and offers different physical forms to choose from, giving customer options for their equipment capability.

MCDEA - 

Methylene bis (2,6-diethyl-3- chloroaniline)

Solid

MCDEA is a solid, high performance, hindered aromatic diamine curative and chain extender for isocyanate and pre-polymers. It affords polyureas with superior mechanical and dynamic properties and extended gel times. MCDEA provides excellent mechanical properties with low hysteresis (heat build-up), excellent temperature resistance up to 150ºC (302ºF), good resiliency, abrasion, wear and tear resistance, and processing advantages.

MCDEA is preferably used with TDI based urethane prepolymers. Gantrade offers high purity - low-color grades of MCDEA in 20kg. packaging.

DETDA - 

3,5-diethytoluene-2,4-diamine and 3,5-diethytoluene-2,6-diamine

Liquid

DETDA is a liquid mixture of 3,5-diethytoluene-2,4-diamine and 3,5-diethytoluene-2,6-diamine used as a specialty curative and chain extender for diisocyanate pre-polymers, creating polyureas with excellent mechanical and dynamic properties. It is also a curing agent for epoxy resins.

DETDA provides excellent mechanical properties with low heat build-up under high compression loads, good resiliency, abrasion, wear and tear resistance, and processing advantages. Gantrade offers a low color DETDA in totes.

DMTDA - Dimethylthiotoluenediamine

Liquid  

DMTDA is a specialty curative and chain extender for diisocyanate pre-polymers, affording polyureas with good mechanical and dynamic properties. It is a viscous liquid used in both hot and room-temperature cast systems. DMTDA can be blended with other liquid diamines to achieve systems with varying cure rates and mechanical properties.

P-1000 - 

p-aminobenzoate ester of PTMEG 1000

Waxy Solid Non-hazardous diamine curative for use with MDI or TDI prepolymers. Can be used to produce room temperature cured systems or to reduce hardness of hot cure elastomers. Exhibits low reactivty.

MBOEA - 

Methylene bis (ortho-ethylaniline)

Liquid

MBOEA is a specialty liquid diamine curative and chain extender for isocyanate pre-polymers, affording polyureas with superior mechanical and dynamic properties. MBOEA provides excellent mechanical properties with low heat build-up under high compression loads, superior hydrolytic resistance at higher temperatures, good resiliency, abrasion, wear and tear resistance.

Gantrade offers MBOEA in drum packaging. Can be used to replace solid diamines yielding properties harder material than MOCA.

MBA-NaCl - 

Sodium chloride complex of Methylene-bis-aniline

Liquid Blocked aromatic diamine curative which offers very long gel time. Curing requires heating the system to 120°C.

Diol Products

HQEE

Solid at room temperature
Good tensile, resilience, tear and cut resistance.

HER

Solid at room temperature
Good tensile, resilience, tear and cut resistance. Easier to process than HQEE

BDO

Liquid at room temperature
The most common curative for MDI prepolymers. These systems generally produce urethane with good abrasion, resilience and compression set. BDO is also a raw material for polyester polyols.

MPO

Liquid at room temperature
Low freezing point (-54°C). MPO is not regulated and exhibits good compatibility with polyether polyols. Lower reactivity than BDO but improved hydrolysis resistance. MPO is used in production of polyester polyols.

PDO

Liquid at room temperature
Similar reactivity to BDO gives elastomers with lower hardness; physical properties similar to BDO; may be more hygroscopic; PDO is used in production of polyester polyols.

HDO

Solid at room temperature
Used in hot melt adhesives and for producing polyester polyols with good performance profiles.

Diol Products

Physical Form at Room Temperature

Product Features

HQEE - 

Hydroquinone bis (2-hydroxyethyl) Ether

Solid

HQEE is a symmetrical aromatic diol chain extender for polyurethanes. The polyurethane cured by HQEE exhibits higher melting temperatures vs. BDO. Therefore, HQEE-based elastomers show greater elevated temperature performance vs. comparable BDO systems. HQEE can improve tensile, hardness and resilience properties in MDI-polyurethane elastomers. HQEE/MDI PUR elastomer series parallels MOCA/TDI.

HER - 

Hydroxyethyl Ether of Resorcinol

Solid

HER is an aromatic diol chain extender. It has good compatibility with MDI systems, which offers excellent performance in CPU, MPU and TPU polymer applications. HER based polyurethane elastomers impart better tear strength, tensile strength, compression set, cut resistance and ease of handling. HER systems maintain maximum endurance, elasticity, plasticity and minimum shrinkage of PU elastomer.

Besides those common advantages of aromatic chain extenders, HER avoids the rapid crystallization vs. HQEE. The melting point of HER is ~ 15°C lower than HQEE and HER exhibits super-cooling behavior, meaning it will stay liquid for a time below its melting point. HQEE crystallizes immediatedly.

BDO - 

1,4-Butanediol

Liquid BDO is a stable, hygroscopic, clear, colorless liquid with a freezing point of 19-20ºC and a boiling point of 230°C. It is used extensively as a chain extender (curative) in production of polyurethane elastomers by reaction with diisocyanates and in the manufacturing of polyester polyols by reaction with dibasic acids. Gantrade offers a low moisture BDO grade (<100ppm) for polyurethane industry.

MPO - 

2-Methyl-1,3-propanediol

Liquid

MPO is a versatile liquid, non-crystallizing, short-chain diol possessing two primary hydroxyl groups. It exhibits a high boiling point of 212ºC and a very low melting point of -54ºC; this contributes to ease in handling. MPO has the same molecular weight+ and equivalent weight as 1,4-butanediol. The branched methyl moiety on MPO imparts good hydrolytic stability in polyesters and polyurethanes, while maintaining good weatherability and product durability. MPO is much less hygroscopic than BDO.

When compared with BDO systems, MPO systems exhibit lower hardness values, increased flexibility, greater transparency, softer feel and increased compatibility with other materials. Gantrade offers MPO in drums and bulk ISO tanks.

PDO - 

1,3-Propanediol

Liquid PDO is a liquid primary diol used as a high reactivity chain extender for polyurethanes or an intermediate for polyester polyols. PDO is a bio-based intermediate. Similar reactivity to BDO gives elastomers with lower hardness; physical properties similar to BDO; may be more hygroscopic.

HDO - 

1,6-Hexanediol

Solid Used in hot melt adhesives and for producing polyester polyols with good performance profiles.

What are Gantrade's custom formulated curatives?

Through our Urethane Laboratory in Charlotte, NC, Gantrade has been custom formulating curatives to meet unique requirements of our customers that cannot be achieved using existing commercial curatives. We offer a wide variety of curative options for the cast elastomer and urea coatings industries. Custom formulations are developed against a set of performance criteria provided by a processor and includes the physical form of the curative, cure profiles and key performance attributes, etc. For further information, please contact our Polyurethane Technical Team, at +(1) 704-887-9470.