Influence of Ethylene Plasma Treatment of Agave Fiber on the Cellular Morphology and Compressive Properties of Low-Density Polyethylene/Ethylene Vinyl Acetate Copolymer/Agave Fiber Composite Foams

Abstract

Agave fibers (AF) were incorporated either pristine (AFp) or surface treated by ethylene plasma (AFm) in low-density polyethylene (LDPE)/ethylene vinyl acetate (EVA) blends at a ratio of 1 : 1 and foamed by chemical means. The role of the AF content (3, 6, 9, 12, and 15 wt.%) and its surface modification on the cellular morphology and mechanical properties of LDPE/EVA/AF foams under compression is investigated herein. Fourier transform-infrared spectroscopy, contact angle, and water suspension of AF suggest that plasma treatment using ethylene successfully modifies the surface nature of AF from hydrophilic to hydrophobic. AF and the surface treatment have an important role on the morphological properties of the foams. Composite foams reinforced with 12 wt.% AFm exhibited the highest mechanical properties improvements. At this fiber content, the composite foams enhanced 30% of the compressive modulus and 23% of the energy absorption under compression with respect to the neat polymer blend foam, as a result to the formation of more uniform cells with smaller size and the enhancement of compatibility and spatial distribution of the AFm in the polymer composite foams due to thin clusters of polyethylene-like polymer deposited on the AF surface.

Extrusion foaming of multiphasic polyethylene/ethylene-vinyl acetate copolymer/carbon nanotube mixtures: Tailoring foam properties by selective localization of nanoparticles

“…Thus, new materials having advantageous properties can be prepared using polymer blending techniques. 10,11 Accordingly, LDPE is typically blended with other polymers with more elastomeric behavior like poly(ethylene-co-vinyl acetate) (EVA). 12,13 The PE/EVA blend foams demonstrate better flexibility, higher toughness, more significant impact resistance, and lower thermal conductivity than LDPE foams.…”

“…It is also worth noting that the PE/EVA blend foams improve resistance to electrical discharge and solvents, stress cracking resistance, weather-ability, creep behavior, and service temperature. [11][12][13] Li et al in 2021 14 prepared microcellular LDPE/EVA foams by using a physical foaming agent, supercritical CO 2 , via a low-temperature solid-state batch foaming process. By using a crosslinking reaction and the presence of micron-size phase-separated domains and crystalline structures, their prepared elastomeric polyolefin foams showed considerable higher tensile and compression strength comparing with other elastomeric polyolefin foams.…”