Surface Modification of Flax Yarns by Enzymatic Treatment and Their Interfacial Adhesion with Thermoset Matrices

Abstract

The aim of this study was to assess the effects of commercially available and relatively inexpensive enzyme preparations based on endo 1,4-β-xylanase, pectinase and xyloglucanase on the thermal (TGA), morphological (SEM), chemical (FT-IR) and mechanical (single yarn tensile tests) properties of flax yarns. The preparation based on pectinase and xyloglucanase provided the best results, resulting in the effective removal of hydrophilic components such as hemicellulose and pectin, the individualization of yarns and increased thermal stability at the expense of a reduction in mechanical properties, depending on the treatment parameters. Single yarn fragmentation tests pointed out an improved interfacial adhesion after enzymatic treatment, with reduced debonding length values of 18% for an epoxy matrix and up to 36% for a vinylester resin compared to untreated flax yarns.

Structural Determination of Pectins by Spectroscopy Methods

“…In pure citrus pectin (available commercially, PectaSol-C, curve A), the first step at 60 • C corresponds to the water molecules and some volatile compounds loss, which confirms a loss of 3.7% of the weight of the PectaSol-C sample. The next steps with three endothermic effects at 200 • C, 229 • C, and 882.7 • C are associated with pyrolytic decomposition, consisting of primary and secondary decarboxylation with an acid side group and carbon in the ring [38,[41][42][43]. The successive mass loss (87.4%) may lead to pectin residue formation.…”

The Water Absorption and Thermal Properties of Green Pterocarpus Angolensis ( Mukwa )-Polylactide Composites

“…Xylanases (hemicellulases) degrade the hemicellulosic components. Pectinases hydrolyse pectin, and laccase is known for degrading lignin (Seghini, et al 2020). Sreekumar et al (2009) examined the effects of benzoylation, sodium hydroxide, silane, and permanganate treatment on the moisture uptake of polyester-sisal fibers.…”

Low-Velocity Impact Analysis of Pineapple Leaf Fiber (PALF) Hybrid Composites

“…Hence, CT is a powerful technique used to check the presence of major defects, such as open cracks and porosity. Besides those defects, a different study shows that micro-CT testing are used to capture the composite debonding length reduction of a surface modification of flax yarns by enzymatic treatment [ 8 ]. Moreover, through X-ray micro computed tomography also can check fiber distribution throughout a composite.…”