Helmut Kleimann

Naphthalene-1.5-Diisocyanate as a Building Block for High Performance Polyurethane Elastomers

For many years naphthalene-1.5-diisocyanate (NDI) has been used in the polyurethane elastomer VULKOLLAN. NDI differs from the widely used diphenylmethane diisocyanate (MDI) and tolulene diisocyanate (TDI) with regard to its rigid structure and high melting point, resulting in sig nificantly higher melting points of the corresponding NDI/glycol hard seg ments. Combined with special polyadipate diols and crosslinked with glycols, NDI has proven to be the key building block to ensure the high property profile of the VULKOLLAN elastomer system. The NDI elastomer combines the elasticity of an ether based material with the toughness of an ester based elastomer.

High-Performance PUR Elastomers with Aromatic Diamines

Solid polyurethane elastomers produced by the casting method are used mainly in technical applications. They bridge the gap between soft rubber grades and hard thermoplastics without losing their excellent elastomeric properties. Current sales and consumption figures confirm the excellent future prospects of these products. The elastomers are produced from modified isocyanates and crosslinking agents. Amine crosslinking agents play a particularly vital role here: they are largely responsible for the processing characteristics of the systems and deter mine many of the final properties of the end products. While looking for suitable amines, we discovered two aromatic diamines capable of either retarding or accelerating the reactivity of the systems. Various ways of formulating systems are demonstrated in the light of these characteristics, and the properties of the end products are discussed. New processing methods should permit cost-effective production and open up new fields of application.