Application of phosphogypsum as a filler for polymer compositions
The article considers the possibility of involving phosphogypsum in the process of polymer materials manufacturing. Phosphogypsum (PG) is industrial waste in production of phosphorus fertilizers. Here, a method of the PG preparation for application as an inorganic filler in compositions with polypropylene and polyvinyl chloride is proposed. The influence of the synthesized inorganic additive, zinc aluminate, on the mechanical properties of the compositions has been studied. The obtained inorganic materials were studied by x-ray phase analysis, microscopic studies. Mechanical and abrasive properties of compositions of the PG and polypropylene, polyvinyl chloride were determined. The moisture absorption of the obtained materials was studied. According to the obtained data, moisture absorption up to 2.0 % (by weight) is established for samples annealed at 800 and 900 <sup>o</sup>C. Chalk (the most commonly used additive in the industry) shows a significantly higher moisture absorption. The heat treated at a temperature of 800 <sup>o</sup>C samples of PG were selected for further studies. It was established that PG can be used as a white filler for polymer products. A simple method of converting of the PG into a practically hydrophobic product including drying of PG at 100 ° C and heat treatment at 800 ° is proposed. When PG is used as an inorganic filler, the abrasive properties of the compositions are improved, which can be useful in the development of filler compositions to reduce the wear of process equipment. The use of PG as an inorganic filler of polymeric materials will solve the problem of releasing the areas occupied by dumps, involving multi-tonnage waste of phosphoric acid production in the recycling processes. The addition of zinc aluminate increases the elasticity of the composition and its elongation. The results can be useful for specialists in polymer industries.