The utilization of fly ash as a filler to strengthen the properties of polybutylene succinate

Abstract

The use of coal as a primary raw material in electrical power generation has been growing exponentially since the 1960s. One of the major drawbacks of concern in electrical power generation through coal utilization is the bulk production of coal fly ash (FA). Fly ash, as a waste product poses a threat to the environment as it contains heavy metals such as aluminium, calcium oxides, potassium, magnesium oxides, silica oxides, and sulphur oxides. When it rains, the heavy metals contained in the fly ash is transferred to nearby water sources through run-off. This can potentially contaminate groundwater and freshwater course posing a threat to humans as well as wildlife and sea-life. Over the recent decade, researchers have been exploring various innovations that can be employed in order to resolve this pollution impediment caused by fly ash. As such, the use of fly ash in various industries ranging from construction, agriculture, and wastewater treatment has gained significant attention. Subsequently, this growing interest has also infiltrated the polymer industries. The excess availability of fly ash (FA) and its high mechanical performance when added to polymer matrices make it an exceptional substitute for commonly used fillers in the industry, thereby enhancing their widespread applications. This study aims to investigate the effect of fly ash at various concentrations viz 1, 3 and 5 %, and how they enhance the properties of polybutylene succinate (PBS). In order to further enhance the flammability resistance of the composites, zinc borate has been added to the polymer composite. The synergistic effect of zinc borate is also examined in this study. Characterization techniques such as scanning electron microscopy (SEM), underwriters laboratory testing 94 (UL 94), rheology, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD) were utilized to analyse the properties of neat PBS, PBS/FA, and PBS/FA/Zinc Borate (ZB) composites. SEM results revealed a better dispersion of fly ash particles in the PBS matrix at 1%, in addition to silane- treated fly ash. Furthermore, silane-treated fly ash showed an enhancement thermal stability when compared with 1% non-treated FA, however, both of them showed better thermal stability than the neat PBS. The FTIR and EDS results suggested that the type of fly ash used in this study is a silicate class (Class F). The water absorption results also showed a decrease in water absorption with silane-treated fly ash samples.