| Summary: | Flame retardants are composite materials or chemicals used in thermoplastics, thermosets, textiles, coatings and glasses that inhibit or resist the spread of fire. In 2014 the global market for flame retardants is expected to reach $6.10 billion with a drive in research for designing and developing new fire resistant materials. A commercially available product based on a hydrogel/glass composite is an effective fire and heat resistant glazing that is employed in the commercial and domestic sector. The macroscopic effects of these materials have been investigated; however no information exists on the molecular level properties. Therefore, the aim of this research is to fully characterise a series of hydrogels with the ultimate goal of understanding structure-property relationships. The hydrogels discussed herein are made by drying commercially available sodium-silicate solutions onto traditional float glass to create a sandwich glazing. The materials present a unique challenge to characterise at the molecular level because of their amorphous and metastable nature. NMR spectroscopy has been extensively used in this research because it is shown to be an ideal technique for the elucidation of structures and dynamics in disordered systems. The complete “life-cycle” of the product is investigated; firstly, using solid-state NMR, a thorough and detailed analysis of the hydrogels are presented. The thermal stability of the hydrogels are then investigated by means of short and long term ageing effects, which shows that the product crystallises into the layered silicate makatite. The ability to improve the longevity of the product by inhibiting makatite formation follows with a final section dedicated to understanding different composites of the materials.
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