Rotational Molding of Linear Low-Density Polyethylene Composites Filled with Wheat Bran

Abstract

Application of lignocellulosic fillers in the manufacturing of wood polymer composites (WPCs) is a very popular trend of research, however it is still rarely observed in the case of rotational molding. The present study aimed to analyze the impact of wheat bran content (from 2.5 wt.% to 20 wt.%) on the performance of rotationally-molded composites based on a linear low-density polyethylene (LLDPE) matrix. Microscopic structure (scanning electron microscopy), as well as physico-mechanical (density, porosity, tensile performance, hardness, rebound resilience, dynamic mechanical analysis), rheological (oscillatory rheometry) and thermo-mechanical (Vicat softening temperature) properties of composites were investigated. Incorporation of 2.5 wt.% and 5 wt.% of wheat bran did not cause significant deterioration of the mechanical performance of the material, despite the presence of ‘pin-holes’ at the surface. Values of tensile strength and rebound resilience were maintained at a very similar level, while hardness was slightly decreased, which was associated with the porosity of the structure. Higher loadings resulted in the deterioration of mechanical performance, which was also expressed by the noticeable rise of the adhesion factor. For lower loadings of filler did not affect the rheological properties. However, composites with 10wt.% and 20 wt.% also showed behavior suitable for rotational molding. The presented results indicate that the manufacturing of thin-walled products based on wood polymer composites via rotational molding should be considered a very interesting direction of research.

Valorization of Invasive Plants from Macaronesia as Filler Materials in the Production of Natural Fiber Composites by Rotational Molding

“…As observed in other studies, larger loadings of fibers led to parts with lower bulk density due to the greater porosity of the composites [ 28 ]. As already mentioned, composites with smaller fiber sizes showed higher number of voids and defects, which also explained their lower densities [ 33 , 34 ]. Untreated Pennisetum composites showed the lowest density values, with no significant differences, also explaining the poor mechanical results obtained for these materials.…”

Application of Walnut Shells-Derived Biopolyol in the Synthesis of Rigid Polyurethane Foams

“…The band located at 1735 cm −1 refers to the C=O vibration of holocellulose [41]. A wide band ranged from 3500 to 3300 cm −1 refers to the hydroxyl groups of lignin [42]. The band related to OH groups is also presented on the FTIR spectrum of the WS-based polyol, which indicates a great number of hydrogen groups.…”

Investigation of the Orientational Mechanical Properties of Biodegradable Extrusion Films Based on Polyolefins and Beet Pulp

“…Filling polymers with vegetable fillers such as wood flour, straw, husk of cereal crops reduces the cost of polymer compositions and can significantly reduce the environmental burden after their use, which is especially important for disposable packaging materials [1][2][3][4][5][6][7][8][9][10][11][12]. Recently, there have appeared a lot of studies , which describe the compositions of biodegradable composites based on thermoplastic polymers and natural fillers such as starch, cellulose, rice husks, wood flour, and cereal straw.…”