Modificación reactiva de betunes con prepolímeros basados en isocianato

Abstract

Bituminous materials present a large set of interesting properties such as impermeability, ductility, adhesivity, resistance to the effect of weathering and chemicals, etc. They all have favoured the development of a wide field of applications that range from the construction of road pavements to more specialized purposes, such as waterproof membranes for the roofing industry. The performance of bitumen has been improved by physical modification with polymeric additives. Physical modification involves high mixing temperatures to effectively disperse the additives. This fact implies oxidative degradation and high cost. In addition, polymer-modified bitumen is usually thermodynamically unstable, and phase separation readily occurs during high temperature storage. In this context, reactive modification is a promising alternative to improve both economic and engineering performance of bituminous products. Reactive polymers are functionalized molecules capable of forming chemical bonds with some bitumen compounds, improving bitumen-polymer compatibility, mechanical behaviour, storage stability and temperature susceptibility of the resulting binders. This work studies the formulation, processing conditions and mechanical properties of bituminous binders prepared by reactive modification of neat bitumen with isocyanate prepolymers, in order to develop competitive bituminous products for both paving and roofing industry