Mechanical properties and microstructure of lightweight polymer composites containing mono and hybrid fillers sourced from recycled solid wastes

摘要

This paper presents the development of lightweight polymer composites containing various solid wastes as fillers. This research is conducted to formulate mix proportions of polymer composite using unsaturated polyester resin as binder and waste tyre rubber crumb, recycled polyethylene terephthalate (PET) flakes and fly ash as fillers. Effects of various volume fractions of rubber crumb, PET flakes and fly ash and their combinations on 3 days compressive strength and density of the polymer composites are studied and a number of optimum mixes are selected for further study. Compressive strength, flexural strength and toughness of the above optimum mixes are measured at 3, 14 and 28 days. The effect of jute fabric as reinforcing layer on flexural strength and toughness of polymer composite is also studied. Microstructure analysis is conducted to investigate the polymer matrix and matrix-fillers interface of the composites. The optimum mix proportions are developed based on usage of least binder and high volume of filling materials, having lightweight and appreciable compressive strength. Results show that the 28-day density and compression strength of polymer composites are in the range of 1072 to 1616 kg/m(3) and 15 to 62 MPa, respectively. These values are well below the American Concrete Institute (ACI)'s light-weight concrete density of 1850 kg/m(3) and compressive strength of 17.5 MPa. The combined use of fly ash with rubber crumb or PET flakes improved the compressive and flexural strengths of polymer composites compared to the use of rubber crumb or PET flakes alone. The use of jute fabric increased the flexural strength and toughness of polymer composites. Microstructural analysis revels no additional substance besides binder and fillers, indicating no reaction of fillers with the resin in the composite. (C) 2021 Elsevier Ltd. All rights reserved.