Polyester composites filled with walnut shell powder: Preparation and thermal characterization

Abstract

This article reports on the fabrication and subsequently on the thermal properties of a biomaterial filled polymer composite consisting of polyester and walnut shell powder (WSP) in different proportions. The focus has been given to the evaluation of effective properties of the composites like thermal conductivity, glass transition temperature, and coefficient of thermal expansion. The experimental findings obtained for thermal conductivity are supported by the mathematical and numerical analysis made under suitable assumptions. A mathematical correlation is proposed to predict the effective thermal conductivity (Keff) of such particulate filled polymer composites. For the numerical study, a commercially available finite‐element package ANSYS19.2R2 is used to calculate the thermal conductivity of the composites. One dimensional heat conduction analysis is performed across composites with the periodic and randomly oriented arrangement of spherical fillers in different concentrations. Thermal conductivities of the composites are measured with Unitherm Model 2022 tester to validate the results. These values are then compared with effective thermal conductivities obtained from the proposed mathematical correlation and are found to be in close agreement with one another. It is concluded from this study that the addition of WSP improves the thermal insulation capability of neat polyester to a reasonable extent.

Analysis, Development, and Scaling-Up of Poly(lactic acid) (PLA) Biocomposites with Hazelnuts Shell Powder (HSP)

“…The shell extracts can be used as natural antioxidants in polymeric matrices as they can act as thermal and photo oxidative stabilizers for different types of polymers, including biopolymers like poly(lactic) acid (PLA) [ 13 , 14 ]. Moreover, the HSP addition enables light biocomposites to be obtained that, in some cases, possess improved mechanical and thermal properties and have enhanced biodegradability, when compared to the pure matrices [ 15 , 16 , 17 , 18 , 19 ]. Furthermore, the incorporation of HSPs into a biopolymeric matrix contributes to reducing the overall biocomposite cost [ 20 ].…”

Epoxy‐hemp and epoxy‐flax composites filled with glass dust for enhanced thermal insulation: An analytical and experimental study

“…Use of coconut shell particles, wood dust, egg shell particles, walnut shell powder, bamboo fillers, peanut shell powder, etc. have been reported by many researchers 14–16 . Al‐Shabander 14 observed that the addition of 10%wt of wood dust reduces the thermal conductivity by about 67.1% in compared with the neat epoxy with the addition of wood dust filler using the Lee's disk thermal test.…”

“…have been reported by many researchers. [14][15][16] Al-Shabander 14 observed that the addition of 10%wt of wood dust reduces the thermal conductivity by about 67.1% in compared with the neat epoxy with the addition of wood dust filler using the Lee's disk thermal test. But they lack high mechanical strength.…”

“…They observed increment in the thermal stability of the composites with PSP (15 wt% of 7% alkali treated). Pradhan et al 16 investigated the thermal properties of polyester composites filled with walnut shell powder (WSP). Their study reported linear decrement of 25% in k eff with 17.95 vol% addition of the WSP.…”

Physical, mechanical, and sliding wear behavior of epoxy composites filled with surface modified walnut shell particulate

“…Against that, they reported achieving improvement in sliding wear resistance under all sliding conditions for filled polyester. Pradhan et al [ 28 ] studied the thermal properties of polyester/walnut shell particulate composites and found that the inclusion of filler enhances the thermal insulation and glass transition temperature of the material, whereas, the coefficient of thermal expansion drastically reduces. Sejkar et al [ 23,29 ] studied the effect of the walnut shell particle size and found that composites prepared with small size particulates bring enhanced properties.…”