Effect of Filler Particle Size on the Recyclability of Fly Ash Filled HDPE Composites.

Mohammed N Alghamdi

doi:10.3390/polym13162836

Abstract

Fly ash polymer composites are innovative high-performance materials that reduce the environmental worries and disposal complications of heavy industry produced fly ash. This study developed and characterized such composites of high-density polyethylene (HDPE) matrices and found that the use of small (50–90 µm) particles of fly ash could give rise to the tensile modulus (~95%) and tensile strength (~7%) of their reinforced composites when compared to neat HDPE materials. While these results themselves convey a strong message of how fly ash can be effectively utilized, this was not the key aim of the current study. The study was extended to examine the effect of fly ash particle size on the recyclability of relevant HDPE composites. The extrusion-based multiple recycling of composites gave slightly lower mechanical properties, primarily due to filler/matrix delamination when large fly ash particles were used. Compared to freshly made fly ash-filled HDPE composites, although using small (50–90 µm) fly ash particles reduced the tensile modulus and tensile strength of recycled composites, the values were still far above those from neat HDPE materials. This novel insight directs the effective utilization of fly ash and provides long-term sustainable and economical solutions for their practical applicability.

Highlights

Fly ashes are highly abundant synthetic materials produced as byproducts in several heavy industries, including cement [1], petroleum [2], and coal-powered power plants [3,4,5]
It was demonstrated in previous works that the use of >10% fly ash further increases the tensile modulus of the FA/high-density polyethylene (HDPE) composites but at a cost of reduced tensile strength [26,27]
Tolhyemreefrorceo,mthpeousisteeds. melt processing temperatOunrecewthase afrnetsichipHaDtePdEtoanbde sFaAfe/HfoDr pPrEosdaumcipnlgeshwigehr-evafalubericpaotleydmaenrdcothmeprmosoitgersa.vimetrically tested, the samples were subjected to recycling by using an extrusion plastometer, without any pre-treatment

Summary

Introduction

Fly ashes are highly abundant synthetic materials produced as byproducts in several heavy industries, including cement [1], petroleum [2], and coal-powered power plants [3,4,5]. The development of fly ash-filled high-density polyethylene (HDPE) composites and the effect of the filler particle size on the thermal, interfacial, and microstructural properties of the composites is initially reported. The study was further guided into a novel investigation that revealed the effect of fly ash particle size on the recyclability of such composites when considering the tensile, thermal, and filler/matrix interfacial properties. This investigation will potentially open a new topic of fly ash-filled polymer composite research as recyclability, which is the key to global circular economy and environmental sustainability

Materials

Experimental Method

Results and Discussion

Mechanical Properties