A new composite made from Luffa Cylindrica and ethylene vinyl acetate (EVA): Mechanical and structural characterization for its use as Mouthguard (MG). (February 2022) - Carmona, Alejandro Restrepo
Abstract: The use of Mouthguards (MGs) in contact sports is an interesting biomedical topic. MGs are protective personal equipment made principally from the copolymer ethylene vinyl acetate (EVA). EVA is a thermoplastic whose thickness and rigidity are variables of concern for a good shock energy absorption capability in an MG. A natural fiber polymer composite is an interesting attempt for tackling these variables. Luffa cylindrica (luffa) is a sponge gourd that grows in 3D structure, which is used mainly as an ornament, a filling, or is trimmed for its use as a bathing product. In this work, a new EVA-luffa composite (EVLc) was made from commercial EVA sheets and luffa mat acting as reinforcement. FTIR, DSC, and TGA tests of EVA revealed its nature compared to literature data. A mechanical testing was applied to eight EVLc ASTM D-638 type V dumbbells (D1-D8) that showed low tensile strength values compared to EVA resistance ranges in literature. SEM images of EVLc's D1-D8 confirmed good adhesion between the reinforcement and matrix without surface treatment, and a descriptive statistical analysis indicated an intrinsic variation. Highlights: A novel composite made from Luffa cylindrica and EVA copolymer is presented in this research. Extensive mechanical and materials characterization was included, showing the potential use for contact sports use. A successful compression molding processing was accomplished for the EVA-luffa composite. A detailed use of proper ASTM norms was applied to the obtention of the adhesion in such a composite.