STUDIES OF MODEL MACROSCOPIC-DEFECT-FREE MATERIALS .1. INVESTIGATIONSOF THE SYSTEM 4CAO AL2O3 FE2O3-4CAO 3AL2O3 SO3-HPMC-H2O BY X-RAY, THERMOANALYTICAL AND NMR TECHNIQUES

Model macroscopic-defect-free (MDF) materials representing selected co mpositions in the system 4CaO . Al2O3 . Fe2O3-4CaO . 3Al2O3 . SO3-hpmc -H2O have been prepared, with a variety of water-to-solid ratios and r eactions quenched at varying times. Product mixtures were examined by analytical X-ray powder diffraction, thermal analyses and Al-27 MAS NM R spectroscopy. Inhibition of crystallisation of hydrated products and elevated temperatures for thermal transformations of those products o ccur in materials prepared under MDF processing conditions, which inco rporate organopolymer (hpmc, hydroxypropylmethylcellulose) into an amo rphous hydrated product. Al-O-C crosslinks can be invoked to explain t he Al-27 spectra, and also the elevation in temperatures of thermal ev ents.