Studies on lignocellulosic fibers of Brazil: Part III – Morphology and properties of Brazilian curauá fibers

Continuing the studies on the Brazilian lignocellulosic fibers, this paper presents chemical, physical, thermal and mechanical properties of curauá fibers, one of the unique fibers of the country. Stress–strain curves as a function of diameter of the fiber and static mechanical properties as functions of diameter, length of the fiber and as function of strain rate are determined for the first time. It was found that the tensile strength (TS) and Young’s modulus (YM) decrease while % strain at break remained constant as fiber diameter increases; decrease of TS and % strain at break and increase in YM as test length increased and an increase in TS and YM but without any change in % strain at break with increase of strain rate. Density, crystallinity, identification of chemical groups and degradation temperatures of these constituents of the fibers have been determined using pycnometer, X-ray diffraction, FTIR, UV and DTA/DSC instruments respectively. Dynamic mechanical analysis was also carried out, which revealed increase in modulus as the water present in the fiber is removed. All the results are discussed in terms of morphological observations including fractography.