Biocomposites from abaca strands and polypropylene. Part I: Evaluation of the tensile properties

Macro and micromechanics analysis of short fiber composites stiffness: The case of old newspaper fibers–polypropylene composites

“…It was found that the Young's modulus of the composite materials, increased linearly with the percentage of reinforcement, this was the expected behavior, considering a good fiber dispersion inside the matrix [27,42]. By using ONF as reinforcing element, the rigidity of the plain matrix increased up to 3.5 times, in composites including 50 wt% of fiber content.…”

“…It has been reported that the value of β is mainly influenced by the fibers orientation and the stress concentration effects at the end of the fibers [44]. A value of β=0.4 has been reported to reproduce adequately results obtained experimentally for natural fiber composites [41,42] The inclusion of the value of E t f in the modified rule of mixtures mROM (Eq.2) [27], enabled calculation of the modulus efficiency factor (η e ).…”

“…It is accepted that the aspect ratio (ratio between fiber, length and diameter) has a role in the final mechanical characteristics of composite materials [18,42,47]. While Hirsch model doesn't explicitly incorporate the aspect ratio in the equations, Tsai-Pagano model (Eq.…”

“…In this case, efficiency factors were found between 0.45 and 0.52. In previous researches [2,26,42,43] it was found that usually the value of efficiency factor was between 0.45 and 0.56.…”

Estimation of the interfacial shears strength, orientation factor and mean equivalent intrinsic tensile strength in old newspaper fiber/polypropylene composites

“…Nonetheless it is difficult to determine this factor for injection molded fiber-polymer systems [23]. The analysis of  1 and  by means Bowyer-Bader methodology and the estimation of  t F by means of Kelly-Tyson modified equation [25] proved to be valid to study micromechanics of composite materials [26][27][28][29][30][31].…”