Reactive elastomeric composites: When rubber meets cement

• Published in: Composites science and technology Vol. 75; pp. 77 - 83
• Main Authors: Robisson, Agathe, Maheshwari, Sudeep, Musso, Simone, Thomas, Jeffrey J., Auzerais, Francois M., Han, Dingzhi, Qu, Meng, Ulm, Franz-Josef
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 11.02.2013; Elsevier
• Subjects: A. Oxides; A. Particle-reinforced composites; Applied sciences; B. Mechanical properties; Butadiene; C. Elastic properties; Cellular; Cements; Composites; D. Dynamic mechanical thermal analysis (DMTA); Exact sciences and technology; Fillers; Forms of application and semi-finished materials; Hydration; Polymer industry, paints, wood; Rubber; Sealing; Swelling; Technology of polymers; A. Particle-reinforced composites; B. Mechanical properties; A. Oxides; C. Elastic properties; D. Dynamic mechanical thermal analysis (DMTA); Elastic modulus; Slag cement; Swelling; Mechanical properties; Dispersion reinforced material; Experimental study; Modeling; Composite material; Molecule scattering; Hydrogenated nitrile rubber; Aqueous medium; Sealing material
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2012.11.012

This paper describes a novel reactive composite material comprised of hydrogenated nitrile butadiene rubber (HNBR) compounded with slag cement. The composite initially looks and behaves like rubber, but when exposed to water it simultaneously swells and stiffens due to hydration of the cement component. The material eventually reaches a stiffness that is intermediate between that of HNBR and hydrated cement, while maintaining a relatively large ductility that is more characteristic of rubber. This behavior, which is ideal for sealing applications, differentiates this material from conventional swellable materials that become less stiff upon swelling. The development of this new type of material was motivated by the requirements of oilfield zonal isolation, where alternatives to cement are needed for some challenging sealing applications. A mechanism for the swelling and stiffening of the reactive composite is proposed: water diffuses into the HNBR matrix and is converted to bound water through hydration reactions with the cement, causing the effective solid filler content of the composite to increase. A model is proposed that treats the composite as a cellular solid with a continuous filler phase (hydrated cement). This model is able to reproduce the observed increase in the elastic modulus with time during exposure to water.