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Kinetics of pore formation and resulting properties of lightweight inorganic polymers
Author(s) -
Denissen Jos,
Kriskova Lubica,
Pontikes Yiannis
Publication year - 2019
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.16301
Subject(s) - kinetics , materials science , foaming agent , compressive strength , oxidizing agent , porosity , chemical engineering , polymer , calorimetry , blowing agent , rheology , isothermal process , absorption of water , chemical kinetics , composite material , chemistry , polyurethane , organic chemistry , thermodynamics , physics , quantum mechanics , engineering
Inorganic polymer ( IP ) foams could be used as an alternative to commonly available cellular concretes. To do so, however, it is crucial to understand how the foaming kinetics and the final foam properties can be controlled and tailored to delivered the desired performance. The research reported in this article investigates the influence of the SiO 2 /Na 2 O ratio of the activating solution, addition time of foaming agent, and temperature, on the reaction kinetics and final properties of a porous IP. The IP s were formed by activating fayalite slag, a by‐product of secondary copper production, with a sodium‐silicate solution. Foaming was achieved by introducing metallic Al into the formulation, oxidizing it in the alkaline environment, liberating H 2 gas, and entrapping it. Reaction kinetics were assessed using isothermal calorimetry, rheology, and a dedicated setup to record the foaming. The mechanical and physical properties of the foam were assessed via compressive strength and water absorption measurements. Microstructural analysis was undertaken using electron microscopy and computed tomography. The results showed that by decreasing the SiO 2 /Na 2 O ratio and/or increasing the temperature, the reaction kinetics were accelerated. Regarding the properties, postponing the initiation of the foaming led to more uniform and smaller pores, resulting in an increased compressive strength‐to‐density ratio.