Egg shell powder extraction and its application for water hyacinth (Eichhornia crassipes) natural fibre polymer composite mechanical, thermal behaviour and characterization analysis: Aquatic waste into sustainable product

The goal of this study is to investigate the morphological and mechanical characteristics of water hyacinth plant fibre polymer composites using the aquatic waste of water hyacinth plant fibre as a reinforcement material. Our main objective has been to make successive sustainable products for commercial and household use using aquatic waste plants. As a filler material, the eggshell powder is used here, which is derived naturally. The composite sample's mechanical properties are increased by this process. A novel way of extracting fibre from hyacinth is used in this study by fabricating a mechanical fibre extraction machine of our own design. The main aim of this work is to convert the biological waste of water hyacinth plants into successful commercial products. Using compression moulding techniques, fibre reinforced polymer composites are produced from water hyacinth plant extracts. ASTM standards are followed for the evaluation of manufactured samples, mechanical tests, and absorption tests. Utilizing TGA analysis, it is possible to identify the maximum withstand and degrading temperatures of composite samples. In order to determine whether FTIR can reveal chemical functional groups and percentage crystallinity, XRD is used as well. The scanning electron microscope is used to locate fibre clusters and brittle fractures in composite samples. With the help of an epoxy resin matrix, the fibres from water hyacinth can be used to make particleboard and other lightweight materials. By the end of this study, it should be able to demonstrate that water hyacinth plant fibres are suitable for use as reinforcement for an epoxy resin matrix.

Use of Cement Suspension as an Alternative Matrix Material for Textile-Reinforced Concrete

Textile-reinforced concrete (TRC) is a material consisting of high-performance concrete (HPC) and tensile reinforcement comprised of carbon roving with epoxy resin matrix. However, the problem of low epoxy resin resistance at higher temperatures persists. In this work, an alternative to the epoxy resin matrix, a non-combustible cement suspension (cement milk) which has proven stability at elevated temperatures, was evaluated. In the first part of the work, microscopic research was carried out to determine the distribution of particle sizes in the cement suspension. Subsequently, five series of plate samples differing in the type of cement and the method of textile reinforcement saturation were designed and prepared. Mechanical experiments (four-point bending tests) were carried out to verify the properties of each sample type. It was found that the highest efficiency of carbon roving saturation was achieved by using finer ground cement (CEM 52.5) and the pressure saturation method. Moreover, this solution also exhibited the best results in the four-point bending test. Finally, the use of CEM 52.5 in the cement matrix appears to be a feasible variant for TRC constructions that could overcome problems with its low temperature resistance.

Understanding the self-polymerization mechanism of dopamine by molecular simulation and applying dopamine surface modification to improve the interfacial adhesion of polyimide fibers with epoxy resin matrix

The object of this paper is to interpret the self-polymerization mechanism of dopamine by molecular simulation and use dopamine polymerization to modify the surface properties of polyimide fibers for improving its interfacial adhesion strength with the epoxy resin matrix. Theoretically, the molecular simulation results of calculated energy band gaps and infrared spectrum of the intermediate products generated in the dopamine self-polymerization process confirmed that the spontaneity of self-polymerization of dopamine and the occurrence of intramolecular cyclization and intermolecular polymerization in the self-polymerization process of dopamine. Moreover, the interaction between polyimide and poly(dopamine) was simulated, and the calculated results showed that the interaction between them depended on hydrogen bonding and was verified by ultrasound treatment. Experimentally, the effect of dopamine treatment concentration on the surface properties of polyimide fibers was investigated. Obviously, after a relatively high dopamine concentration treatment, the surface roughness and surface energy of polyimide fibers were largely improved and the number of active groups on polyimide fibers surface were increased, which were altogether conducive to enhance the adhesion strength of polyimide fibers with the epoxy resin matrix.