Reinforced Polyureas; High Temperature Performance and Dimensional Stability

A new polyurea RIM elastomer suitable for molding large parts and offering significant improvements in high temperature properties, impact strength and dimensional stability relative to current automotive grade RIM elastomers has been developed by ICI Polyurethanes (Rubicon Chemicals Inc.). The evolution of RIM materials leading to the development of this innovative product is described herein. Related advances in the in-situ treatment of flaked glass reinforcements leading to improvements in demold toughness, heat sag, and coefficient of linear thermal expansion are also detailed. Physical properties illustrating the benefits of this new polyurea RIM system are compared to amorphous nylon and a polyphenylene oxide/nylon alloy.