Geopolymers based on a coarse low-purity kaolin mineral: Mechanical strength as a function of the chemical composition and temperature

Geopolymer/PEG Hybrid Materials Synthesis and Investigation of the Polymer Influence on Microstructure and Mechanical Behavior

“…between the two phases, or second class hybrids, if strong bonds (covalent bond or ionic-covalent bond) occurred. In literature, numerous works describe the use of FT-IR spectroscopy and solid-state 13 C NMR techniques to study the interaction in biphasic systems. Wang et al 22 demonstrated the formation of hydrogen bonds between the hydroxyl groups of poly(4-vinylphenol) and the poly(ε-caprolactone) (PCL) carbonyl using 13 C NMR [22] .…”

“…Wang et al 22 demonstrated the formation of hydrogen bonds between the hydroxyl groups of poly(4-vinylphenol) and the poly(ε-caprolactone) (PCL) carbonyl using 13 C NMR [22] . Both static and CP-MAS 13 C NMR and FT-IR were used to investigate the interactions that occur in numerous hybrids nanocomposite materials between different polimers and several inorganic matrices (e.g. CaCO 3 [23] , CaO and/or SiO 2 [24][25][26][27][28][29] , TiO 2 [30,31] , ZrO 2 [24,[32][33][34][35] ).…”

“…Moreover, Burciaga-Diaz et al 13 showed that an interesting increase in compression strength can be obtained by using geopolymers with a low content of metakaolinite, obtaining a product made of amorphous silicoaluminate intermixed with silica gel; they also defined some optimal ratios to increase strength in terms of SiO 2 /Al 2 O 3 and Na 2 O/ Al 2 O 3 and determined the best curing conditions (24 h at 80 °C) to obtain a quick strength gain at an early maturation stage, even if for time-delayed uses the best curing conditions were found at 20 °C.…”

Potencial del método de síntesis de materiales cerámico-cementicios procesados por vías alternativas

“…The kaolinitic minerals may contain impurities such as quartz and other clays, as well as the substitution of iron and/or titanium for aluminum. Regarding the purity, previous work in Cinvestav Saltillo (Arellano-Aguilar et al, 2014, Burciaga-Diaz et al, 2012, Burciaga, 2014 has shown that even low purity metakaolinitic minerals are useful to produce CMC.…”

“…The CMC harden by virtue of chemical reactions that advance gradually with time, reaching properties of interest for a wide range of applications. The preparation of CMC depends on various factors, for which their effect has not been completely understood according to the literature, some of these are: (a) Type and amount of chemical activator (b) Thermal treatment (c) Chemical composition of the mineral (d) Glassy fraction of the mineral (e) Particle size (f) Amount of water The chemical composition of the overall formulation plays a major role that defines the mechanical strength (Burciaga-Diaz et al, 2012); it is defined on the basis of molar ratios such as: SiO2/Al2O3, M2O/Al2O3 y M2O/H2O (Burciaga-Diaz and Escalante-García, 2004). The literature indicates variable compositional ranges for several raw materials; the ratios reported by the patents of Davidovits, do not always result in the best properties for any raw material.…”