High-Perfomance Polyureas Derived from New Low-Unsaturation High Molecular Weight Polyamines
High-molecular weight polyamines are useful in polyurea applications which require high elongation and flexibility, as well as excellent chemical resistance, rapid cure, and insensitivity to moisture. Conventional polyetheramines have dominated the market for the past thirty years. These PPG-based polyamines contain moderate levels of unsaturation (0.10 to 0.04 meq/g), which can result in chain termination events, effectively reducing the rate of molecular weight build, leading to relatively low molecular weight of the resulting polymer. Often, the primary amine functionality of conventional (DMC catalyzed) polyetheramines is low due to incomplete amination (approximately 85% conversion efficiency). The performance properties of polymers derived from conventional polyamines are limited by the relatively high levels of unsaturation present in the polyamines.
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Friday, October 09, 2009
