Influence of alkaline hornification treatment cycles on the mechanical behavior in curaua fibers

Abstract

A well‐known treatment applied in vegetable fibers in both paper and cellulose industry is named hornification. This treatment consists in soaking and drying cycles aiming promoting a reducing in the water absorption capability of the fibers, which causes a stiffening in the cellulosic structure increasing the dimensional stability and consequently their mechanical properties. In this work is presented an analysis of the effect of alkaline hornification, using a calcium hydroxide (CH) 0.7% w/v solution, after 01, 05, and 10 cycles of soaking and drying on the structure changes, mechanical answer, durability performance, and adherence behavior of curaua fibers in the cementitious matrix. The fiber structure as well as their physical and chemical characteristics are evaluated before and after hornification treatment by X‐ray diffraction (DRX), Thermogravimetry (TGA), Fourier Transformade Infrared (FTIR), and Scanning Electronic Microscope (SEM), while their mechanical answer is evaluated by direct tensile tests. The obtained results indicate that the hornification treatment alters the morphological, physical, and chemical fiber properties, improving their mechanical properties. However, when the number of cycles is excessive, this kind of treatment may cause a decreasing in fiber mechanical properties.