Synthesis and characterization of high density polyethylene / peat ash composites.

Abstract

A new type of polymer composite was synthesized from one industrial waste, peat ash, at varying mixing ratios of high density polyethylene (HDPE) and the resulting products were characterized using different experiments included fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), melt flow index (MFI), density, wettability, tensile test, flexural test and cost analysis. The effects of various ash loads and the use of the maleic anhydride grafted high density polyethylene (HDPE-g-MA) compatibilizer on the physical and mechanical properties of composites were investigated. It was observed that the utilization of peat ash significantly increases the tensile strengths and the flexural modulus, also reduces the cost. Higher peat ash ratios generally lead to higher tensile, flexural strengths and lower cost. Incorporating (HDPE-g-MA) in the composites formulation led to a significant increase in tensile and flexural properties. Conversely, there was a significant decrease of impact strength found for all composites in comparison to the virgin HDPE. And the impact strengths generally decrease as peat ash content increases. Microstructural analysis showed that surface treated peat ash particles appeared to be incorporated into the HDPE matrix as less debonding and voids were observed. In addition, the melt flow ability of the composites decreased remarkably with an increase in peat ash content. No significant water uptake effect was detected on peat ash composites indicating that these materials could be used as a direct replacement for HDPE in applications where impact strength is no a critical factor. Furthermore, due to the heavier components of peat ash and lack of the voids between filler and matrix, the use of peat ash increased the composite density in comparison to HDPE. Nevertheless, as peat ash reinforcement does offer increased tensile and flexural properties, this may make the end product lighter as lower wall thickness parts can be used to fulfil the same function. From this study, it was concluded that the utilization of the peat ash from peat fired power stations has proved to have significant value-added potential as a filler material in polymer composites.