Evaluation of the Curing Kinetics for a Geopolymer using Differential Scanning Calorimetry

摘要

Geopolymers are a novel family of inorganic polymeric materials whose principalrnconstituents are silicon, aluminum, oxygen, sodium or potassium and water with uniquernproperties that make them promising candidates in several engineering applications. Arngeoplymeric material of the Na-PSS type with Si/Al ratio of 1.82 was synthesized using lowcost,rncommercially available materials. The objective of this work was to find the time requiredrnfor this type of geopolymer to cure at ambient temperature. A differential scanning calorimetryrnstudy was conducted in order to find the activation energy, frequency factor, reaction order, amdrnheat of reaction. The calculated values were used to solve the Arrhenius equation for differentrnvalues of reaction order and compared with experimental observations. It was observed that thernArrhenius equation with a reaction order of 3 gives a good approximation between the observedrnand calculated curing time for this type of geopolymer. Once an estimate of thermal propertiesrnand reaction parameters were determined, these were used to consider the general case for curingrnof the geopolymer in practical applications.