The Influence of Chemically Pre-treated Chestnut Waste and Pinecone Filler Content on the Properties of Polyester Composites

Abstract

There is critical concern about meeting future global demand for materials because of the depletion of natural resources. In particular, the balance between future demand and sustainable supply will require a great deal of attention in years to come. The interest in the long term sustainability of material resources has led to advancements in bio-composite or polymer composite materials that are made from natural fibers and resin. Pinecones and chestnut waste are most often used as the biomass/biochar source. Nature proposes, and man disposes; we have to find or create new forms of pinecone and chestnut waste to increase their value and for environmental reasons. That is why the current waste was processed and transformed to filler in an up-graded state. In this study, composites were manufactured using chestnut waste and pinecone powder as filler and polyester as the polymer matrix. In addition, methyl ethyl ketone peroxide as hardener and cobalt naphthenate as accelerator were used to produce polyester composite. Raw materials of the fillers were treated with sodium hydroxide solution. The polyester amount was kept constant while the filler ratio was increased from 3% to 12% by weight. The similarities and differences between composites with different fillers and chemical pre-treatments were assessed by evaluating certain mechanical properties such as flexural strength, elastic modulus and hardness and various physical features such as density, open porosity percentage and water absorption. According to the experimental results, increasing the ratio of both chestnut and pinecone powder led to a decrease in the bending strength and an increase in the elastic modulus. Higher properties were associated with the chestnut waste/polyester composite than the pinecone powder/polyester composite.