The Role of Polyethylene Glycol, a Water Entrainer on Characteristics of Silico Alumino Phosphate Geopolymer to Harvest Enhanced Gel Phase and Stability

Geopolymers display a typical brittle mechanical behaviour with low ductility and low fracture toughness. These properties might represent a significant limitation for structural applicationsoffers steric entrapping of the organic molecule and thus structuring the solvated cations in the solution so as to enhance the hydrogen bonding between organic polymer and oxides in the inorganic framework. Research efforts have been done on the use of soluble organic polymer in alkali-activated geopolymers in general but studies on their role in phosphate elaborated geopolymers are rare. In view of the above, this research investigates the preparation of the Polyethylene glycol /Metakaolin geopolymer with silico alumino phosphate gel structure under ambient curing conditions and its performance compared with control samples cured at ambient as well at 80 °C temperature. The effect of PEG at different doses 0–3% (MKGP1, MKGP2 and MKGP3) in metakaolin reaction under phosphoric acid of molarity 10 M was studied by measuring compressive strength, flexural strength while tracing and identification of the formed gel network by employing X-ray diffraction, FTIR and Scanning electron microscopic analysis. Strength analysis showed an enhancement with about more than 50% gain in compressive strength in polymer-assisted samples than that of the control samples (MKGP0) which were 12.1 MPa at (ambient ) 18.8 MPa at 80 °C curing. XRD assemblages and FTIR spectral data proved an increased amorphous gel with PEG addition of up to 3% with the refinement of pores. Dense microstructure in blended samples was evident from SEM analysis. The total weight loss by heating the samples in TGA /DTA was found to be lower in PEG samples (29%) and for control mixes as high as 49%. The study results offer valuable organic-geopolymeric composites with better mechanical properties that can be applied for various potential applications as coatings, restoration and conservation domain. Graphical Abstract