New covalent bonded polymer–calcium silicate hydrate composites

Abstract

New covalent bonded polymer-calcium silicate hydrate (C-S-H) composites were prepared. For this purpose, two sets of hydrosoluble copolymers, both containing trialkoxysilane (T-silane) and/or methyldialkoxysilane (D-silane) functions, were synthesized. The addition of these polymers during the synthesis of C-S-H by the sol-gel method allowed us to obtain hybrid materials. The influence of different synthesis parameters, such as the silane content and the nature of the silane functions grafted to the polymer backbone, was studied. Characterisation of the composite materials by thermogravimetry and elemental analysis showed that chemical interaction of polymers and C-S-H is due only to the presence of T-silane functions. 29 Si CP MAS NMR analysis confirmed the existence of covalent linkages between the inorganic silicate chains of the C-S-H crystallites and the T-silane functions. The specific incorporation of these new classes of silane-modified polymers in C-S-H structure may be successfully used in the preparation of new polymer-cement composites with reinforced mechanical properties.

Chemical functionalization of ceramic tile surfaces by silane coupling agents: polymer modified mortar adhesion mechanism implications

“…Minet et al 13 and Franceschini et al 14 have shown the incorporation of organic groups from alkoxysilanes in calcium silicate hydrates in alkaline media at room temperature without disrupting the C-S-H inorganic framework. These results were obtained for very small organic groups, like amines (-NH 2 ).…”

“…In all cases, it was observed an increase on mechanical properties, but the mechanism of interaction was not deeply investigated. More recently, it was identified the possibility of developing strong bonds between some organosilanes and cement through covalent bonds [12][13][14] . Moreover, when considering EVA interaction with organosilanes, limited content of researches have been published and minor improvement on adherence was actually achieved 15,16 .…”

Propriedades mecânicas de materiais compósitos à base de cimento Portland e resina epoxi

“…Em termos de microestrutura, a fase polimérica tende a recobrir os grãos não hidratados de cimento, retardando o processo de hidratação parcialmente ou completamente. Em alguns casos, promove maior formação de produtos internos do que produtos externos de C 3 S, além de evitar a formação de cristais de etringita durante o processo inicial de hidratação [5][6][7]. Porém, é bem possível que a maior vantagem desses sistemas seja a redução da porosidade, com conseqüente diminuição dos caminhos livres para propagação de fissuras e aumento da resistência mecânica final [8].…”

Evolution of the Elastic Properties of an Oilwell Cement Paste at Very Early Age under Downhole Conditions: Characterization and Modelling

“…10). Indeed, the piezoelectric transducer emits a shear wave and a compression wave of lower amplitude which propagates more quickly in the sample than the shear wave [41]. The signal processing allows the separation between compression and shear waves.…”