Flexural Properties and Low-Velocity Impact Behavior of Polyamide 11/Basalt Fiber Fabric Laminates

Abstract

Environmentally friendly composite plates intended for load-bearing applications were prepared and systematically characterized in terms of mechanical performances and morphological features. Sample plates combining two extrusion grades of bio-polyamide 11, one of which is plasticized, and two basalt fiber fabrics (plain weave and twill architectures) were obtained by film stacking and hot pressing, and their mechanical properties were investigated by quasi-static flexural and low-velocity impact tests. The comparative analysis of the results, also interpreted by the bending damage analysis, through optical microscope observations, and impact damage analysis through visual inspection and indentation measurements demonstrate that, besides interfacial adhesion issues, the mechanical performance of the laminates need to be optimized through a careful selection of the constituents in the light of the final application. In particular, if the goal is a gain in impact strength, the use of the plasticized matrix is beneficial, but it brings about a loss in stiffness and strength that can be partially compensated by properly selecting a more performing fiber fabric architecture. The latter must also be easily permeated by the matrix to enhance the efficiency of stress transfer from the matrix. Overall, our results can be exploited for the development of bio-composites for particularly demanding applications.

Toughened Bio-Polyamide 11 for Impact-Resistant Intraply Basalt/Flax Hybrid Composites

“…This damage degree is achieved at 20 J for the present work composite entailing a significant improvement in impact resistance. Furthermore, Vitiello et al [45] evaluated the impact resistance of PA11/basalt composites with a fiber volume fraction of 0.45 and a thickness of 3 mm. Their composites display peak forces and maximum displacements comparable with the ones obtained in this work but are characterized by a damage degree almost 30-60% lower.…”

Low Molecular Weight Bio-Polyamide 11 Composites Reinforced with Flax and Intraply Flax/Basalt Hybrid Fabrics for Eco-Friendlier Transportation Components

“…The [0/90] configuration featured intermediate quasi-static properties with a flexural stiffness closer to the [0/0] upper limit. The obtained results are promising, considering that Vitiello et al [43] reported a 15.7 GPa flexural stiffness and a 174 MPa flexural strength for a regular PA11 matrix reinforced with a basalt 2 × 2 twill, and Vitiello et al [44] acknowledged a bending stiffness of around 13 GPa and a strength of around 130 MPa for a PA11 reinforced with a plain-weave basalt fabric. The results compare favorably even with more traditional composite configurations, such as polypropylene (PP) glass-reinforced ones.…”

Damage detection in bio-polyamide 11/woven basalt fibres composite laminates subjected to dynamic events

“…[17][18][19][20][21][22][23] Basalt is a rock of volcanic origin that can be transformed into fibers with a melt spinning process similar to that used for the production of glass fibers. Over the last few years, the easy handling, reduced abrasiveness and low cost have fueled a growing and rapid interest in these fibers as valid alternatives to conventional ones, [24][25][26][27][28] and experimental indications are available on the preparation and characterization of many thermoplastic polymers, [29][30][31][32] including basalt fibres.…”