Design of fiber-reinforced polymer damping laminates has been attracting great interest in industrial sectors for lightweight structural damping applications. The present work investigates the impact of skin, core, neutral, and alternate intertwined basalt/flax fabric on the mechanical and vibrational properties of the newly designed polymeric laminate. The designed sequence structure was fabricated using a wet hand lay-up technique with hydraulic compression. Tensile and flexural strength of intertwined multilayer basalt/flax woven composite were studied. An effect of the intertwining on the tensile and flexural strength fractured surface of the composites has been further evaluated. Free vibration technique was used for recording vibration response and the related damping frequencies of intertwining composites. A cantilever mode impact hammer was used for generating periodic signals of the designed composite systems. Damping ratios and damped natural frequencies were calculated with several plies and sequence of flax/basalt woven in the composite. The experimental results revealed that the damped natural frequencies of class II, skin basalt layer intertwined seven core flax layered composite (B2F7) was high, followed by two skin basalt layers intertwined core flax layered composite (B4F5). The addition of the flax layer enhanced the natural frequency to the higher value. It was found that the skin basalt layer with intertwined flax layered B2F7 design structure exhibits maximum damping value with acceptable mechanical properties.

A novel cellulosic fibre was extracted from the peduncle portion of the fish tail palm tree and the extracted fish tail palm fibre was treated with different concentrations (1%, 5%, and 9%) of silane solution. The characteristic analysis on chemical, functional, mechanical and surface property of the extracted fish tail palm fibres were investigated through chemical composition analysis, Fourier Transform InfraRed spectroscopy (FT-IR), single fibre tensile test, and Scanning Electron Microscopy (SEM). Chemical analysis results indicate that silane treatment improved the cellulose content of the fish tail palm fibre. The highest cellulose content of 72.51% was observed in the 9% silane treated fish tail palm fibre. Also, it improved crystallinity index value of 62.5% for 5% silane treated fibre, which is confirmed through the X-ray diffraction analysis. FT-IR result indicates the removal of hemicellulose at characteristic wavelength of 1745 cm −1 for 5% silane treated fish tail palm fibre. Tensile property of the silane treated fish tail palm fibre (1, 5, and 9%) shows an increased tensile strength of 7.3%, 12%, and 6.6% as compared to raw fish tail palm fibre. Moreover, this type of novel natural fibres can reduce the cost while offering competent performance during the polymer-based product development.

Natural fiber and particulates are being exploited to attain eco-friendly products for construction and automotive sectors. These sectors are moving towards the use of high damping characteristic natural biofibers and particulate-reinforced polymer composite as part of the structural components. In this work, woven flax fiber (0° and 90°) and almond shell particulates were used. They were subsequently treated with alkaline and acetylene chemical solution separately. Polymer composite laminates were prepared using a vinyl ester resin as matrix and by stacking flax fibers and almond particulates interleaved in an alternative sequence using the hand layup technique. This was followed by hydraulic pressing. Composite laminates were fabricated by varying the almond shell particulate weight fraction of 0%, 5%, 10%, and 15%. Mechanical properties such as tensile and flexural strength were experimentally measured. Dynamic thermomechanical analysis was conducted on the alkaline-treated and untreated composites with different frequencies for the assessment of the damping characteristics. The alkaline-treated interleaved almond shell and flax fiber composite showed considerably higher damping characteristics. This could be due to the improved adhesion between the matrix and reinforcements. An addition of almond shell particulate positively increased the strength and stiffness of composites.

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This paper deals with the influence of inorganic electrical insulator waste filler on the properties of glass fiber reinforced epoxy composite. The electrical insulator waste fillers were uniformly mixed in the resin through ultrasonication technique. Composites were made up with different percentages of filler (0, 5, 10, 20 wt%) and 20 wt% glass fiber using the hand lay-up method. Physical, mechanical, water absorption, thermal, and dynamic mechanical properties were studied. The experimental results indicate an increase in water absorption and density of composites with increased electrical insulator waste filler in the polymer matrix. Furthermore, the filler addition reduces the tensile strength and increases the flexural strength to 402 MPa at 20% addition. The thermogravimetric analysis reveals that the incorporation of electrical insulator waste filler increases the thermal stability considerably. Dynamic property reveals the damping property of the materials, in which the incorporation of 20% filler leads to higher storage modulus. Particle dispersion and failure mode were analyzed using scanning electron microscope. This work highlights the possibility for reprocessing electrical insulator waste as low-cost reinforcement in polymer composites.