Mechanical Properties of Hybrid Carbonized Plant Fibers Reinforced Bio-Based Epoxy Laminates.

Edgar Adrián Franco-Urquiza,Raúl Samir Saleme-Osornio,Rodrigo Ramírez-Aguilar

doi:10.3390/polym13193435

Edgar Adrián Franco-Urquiza, Raúl Samir Saleme-Osornio + Show 1 more

Open Access

https://doi.org/10.3390/polym13193435

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Abstract

In this work, henequen and ixlte plant fibers were carbonized in a horizontal quartz tube furnace. Several carbonized and non-carbonized fiber fabric configurations were impregnated with a bio-based epoxy resin through the infuseon process. The infrared spectra revealed characteristic bands of styrene instead of organic compounds, representing that the carbonization procedure was adequate to carbonize the plant fibers. The porosity volume ratio for the non-carbonized henequen laminates showed the highest number of voids >1.9%, and the rest of the composites had a similar void density between 1.2–1.7%. The storage modulus of the non-carbonized and carbonized henequen laminates resulted in 2268.5 MPa and 2092.1 MPa, respectively. The storage modulus of the carbonized ixtle laminates was 1541.4 MPa, which is 37.8% higher than the non-carbonized ixtle laminates and 12% higher than henequen composites. The laminates were subject to thermal shock cycling, and tomography scans revealed no alterations on the porosity level or in the cracks after the cycling procedure. Thermal shock cycling promoted the post-curing effect by increasing the glass transition temperature. The viscoelastic results showed a variation in the storage modulus when the carbonized fiber fabrics were located between natural fiber fabrics, which was attributed to more excellent compaction during the infusion process. Variations in the viscoelastic behavior were observed between the different types of natural fibers, which influenced the mechanical properties.

Highlights

Biolaminates are natural fiber-reinforced bio-based epoxy resins [1,2,3]
Vegetable oils obtained from soybeans and flaxseeds are suitable for producing epoxy groups with high functionality due to their relatively high iodine value and high unsaturated fatty acid content [4,5,6]
Recent evaluations have reported that bio-based epoxy resins synthesized from functionalized natural compounds may have comparable thermal and mechanical properties with commercial epoxy resins [2,4,6,7,8,9,10,11]

Summary

Introduction

Biolaminates are natural fiber-reinforced bio-based epoxy resins [1,2,3]. Vegetable oils obtained from soybeans and flaxseeds are suitable for producing epoxy groups with high functionality due to their relatively high iodine value and high unsaturated fatty acid content [4,5,6]. Plant fibers have many advantages over synthetic fibers due to their abundance, low cost, high specific mechanical properties, and density values of 1.2 to 1.6 g/cm, all of which allow the manufacturing of lightweight composites. They are attractive for various sectors such as the infrastructure, aviation, or automobile industries. The authors observed that both precursors were suitable for continuous processing in terms of mechanical stability, and this resulted in carbonized fibers with a significant increase in the mechanical properties, especially in Young’s modulus They recognized the need for deeper studies in order to evaluate the resulting structural changes. Of particular interest is in the mechanical properties that are demonstrated when these hybrid bio-laminates are subject to thermal shock cycles, which allows the discovery of multiple industrial applications

Materials

Composite Manufacturing and Testing

Findings

C C I CCCCCCCCC