PurinElas - MDI Elastomers
MDI elastomers are designed as two-component or three-component. While these components can be MDI-based prepolymer and short chain polyol components, sometimes they can be mixtures of prepolymer, short chain polyol and long chain polyol.
1,4-butanediol is short-chain polyols in elastomers. In addition, HQEE, 1,3-propanediol and other similar materials are also used.
Raw material selection and appropriate hardness are determined according to the desired performance for the application area. For this, a prepolymer and polyol mixtures with the appropriate polyol system are determined. Appropriate mixing systems are designed with short chain polyols.
As with TDI systems, these applications are usually carried out at high temperatures. The most important difference is that TDI prepolymers and the amine derivatives used are more harmful than MDI systems.
We can summarize the differences between TDI and MDI elastomers as follows;
|TDI Elastomers||MDI Elastomers|
|Not sensitive to moisture||Very sensitive to moisture|
|Easy to mix||Care should be taken to mix|
|Manufacturing is not so critical||Require precision manufacturing|
|Up to 85D Shore hardness||Have a very wide hardness range|
|Short reaction time (cure)||Sometimes long reaction time (cure)|
|Not very sensitive to Cure parameters||Very sensitive to Cure parameters|
|Pot life and demoulding time difficult to adjust||Easy to adjust pot life and demoulding time|
|Mixture viscosity increases slowly||Mixture viscosity increases rapidly|
|MDI Ester||MDI Eter|
|Main Features||Main Features|
|Excellent abrasion and tear resistance||High abrasion resistance|
|Good chemical resistance||High resilience|
|Excellent dynamic properties||Excellent hydrolysis resistance|
|Excellent resistance to internal heat build-up||Excellent resistance to microorganisms|
|Compatible with food contact|
|Doffer (for cotton picking machines)||Flotation cells|
|Squeegee / Windshield wiper||Timing belt|
|Wheel casting||Textile rollers|
|Mine dumping site|