Flexural Properties of Wheat Straw Reinforced Polyester Composites

Abstract

A study on the flexural properties of wheat straw reinforced polyester composites is presented in this paper.The wheat straw/polyester composites were made as per the hand layup procedure and the instructions provided by the manufacturers. These specimens were then tested in the three point bend configuration in accordance with ASTM D790-07 at a span to depth ratio of 16. Four weight fractions of wheat straw 2%, 4%, 6% and 8% were chosen to be studied. The process-induced voids were studied and it is shown that voids play an important role in flexural properties. When voids exist, flexural modulus was calculated using a micromechanical model. It is shown from both the experimental results and calculation that flexural modulus decreases with the addition of wheat straw, and this reduction in flexural modulus is due to process-induced voids. Flexural strength of polyester resins does not increase with the addition of wheat straw as reinforcement. This is due to poor interfacial adhesion and the existence of voids. In order to achieve reinforcement, treatment of straw fibers and better processing techniques to reduce voids are needed.

Effect of alkali treatment on the thermal properties of wheat straw fiber reinforced epoxy composites

“…They observed that flexural modulus decreases with the addition of wheat straw in both results; this reduction is due to the presence of process-induced voids. 9 Obele et al worked on the polypropylene/WSF as well as polypropylene/ WSF/maleic anhydride at different fiber loadings and found that mechanical properties are decreasing as increases of the fiber content but the addition of maleic anhydride improved these properties. 10 Liany et al studied the high-density polyethylene/wheat straw composites incorporated with the various concentrations of magnesium hydroxide, nanoclay, and also used the maleic anhydride-grafted polyethylene as a compatibilizer at constant content.…”

Polycaprolactone (PCL) based polymer composites filled wheat straw flour

“…PCL is more costly than many other synthetic plastics. For different application areas, the use lignocellulosic filler in PCL matrix were investigated (Ruseckaite and Jimenez, 2003;Mishra and Sain, 2009;Dong and Davies, 2011; Lignocellulosic filler has several advantages including abundance, low cost and high modulus of elasticity (Hornsby et al, 1997;Velde and Kiekens, 2002). For this purpose some researchers have used various polymer and lignocellulosic fiber (Donmez Cavdar et al, 2011;Kaymakci et al, 2013;Donmez Cavdar et al, 2015).…”

Effect of fibre loading on mechanical properties of jute fibre bundle reinforced gypsum composites

“…When fibre bundle is incorporated into the composite, flexural strength decreases up to 8% loading of fibre bundle. This occurs due to weak interlocking among the matrix molecules and due to the existence of voids inside the composite [ 31 , 32 ].…”