Influence of the Size of the Fiber Filler of Corn Stalks in the Polylactide Matrix Composite on the Mechanical and Thermomechanical Properties

Abstract

This paper presents results of a study on the effect of filler size in the form of 15 wt% corn stalk (CS) fibers on the mechanical and thermomechanical properties of polylactide (PLA) matrix composites. In the test, polylactidic acid (PLA) is filled with four types of length of corn stalk fibers with a diameter of 1 mm, 1.6 mm, 2 mm and 4 mm. The composites were composed by single screw extrusion and then samples were prepared by injection molding. The mechanical properties of the composites were determined by static tensile test, static bending test and Charpy impact test while the thermo-mechanical properties were determined by dynamic mechanical thermal analysis (DMTA). The composite structures were also observed using X-ray microcomputed tomography and scanning electron microscopy. In the PLA/CS composites, as the filler fiber diameter increased, the degradation of mechanical properties relative to the matrix was observed including tensile strength (decrease 22.9–51.1%), bending strength (decrease 18.9–36.6%) and impact energy absorption (decrease 58.8–69.8%). On the basis of 3D images of the composite structures for the filler particles larger than 2 mm a weak dispersion with the filler was observed, which is reflected in a significant deterioration of the mechanical and thermomechanical properties of the composite. The best mechanical and thermomechanical properties were found in the composite with filler fiber of 1 mm diameter. Processing resulted in a more than 6-fold decrease in filler fiber length from 719 ± 190 µm, 893 ± 291 µm, 1073 ± 219 µm, and 1698 ± 636 µm for CS1, CS1.6, CS2, and CS4 fractions, respectively, to 104 ± 43 µm, 123 ± 60 µm, 173 ± 60 µm, and 227 ± 89 µm. The fabricated green composites with 1 to 2 mm corn stalk fiber filler are an alternative to traditional plastic based materials in some applications.

Biodegradable polymer composite containing ground corn stalk modified with polydopamine

“…Corn stalks can also be used as a filler for polymeric materials. 14 This article presents the results of research on the influence of the filler size in the form of 15 wt.% of corn stalk fibers on the mechanical and thermomechanical properties of composites based on polylactide. Corn stalk fiber was used in four sizes-1, 1.6, 2, and 4 mm.…”

Effect of lignocellulosic corn stalk on mechanical, physical, and thermal properties of injection moulded low density polyethylene composites: An approach towards a circular economy

“…Composites are mixtures of two or more different materials that possess superior properties compared to those of individual materials that participate in the fabrication of composites [ 19 , 20 ]. The investigations of corn stalk waste reinforced composites have pulled in due thought from academicians and industrialists for their unrivalled properties such as improved mechanical characteristics, reduced density, biodegradability and eco-accommodating materials [ [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] ] ( Table S1 ). Chen et al [ 29 ] utilised corn stalk flour and hybridized it with sisal fibres for the fabrication of PVC based composites.…”