Development of Novel Polymer Matrix Composites and their Processing for Enhanced Damping

This thesis advances the field of polymer matrix composites by developing materials with enhanced damping properties. The focus is on the integration of soft elastomers along with the proper use of compatibilizers and basalt fibers into methyl methacrylate-acrylonitrile butadiene styrene (MABS) matrix. By employing a novel multiphase binary polymer blend approach, this research investigates the viscoelastic property enhancement through the strategic incorporation of dynamically vulcanized alloys, specifically ethylene propylene diene monomar rubber (EPDM) particles within a polypropylene (PP) matrix (Santoprene) and a styrene-based thermoplastic elastomer (VDT).The research employs a methodology that combines experimental and computational modeling to develop polymer blends with superior damping properties. This includes detailed morphological, mechanical, and viscoelastic characterizations using stateof- the-art techniques such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier-transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), laser microscopy, and scanning transmission electron microscopy (STEM). The comprehensive analysis reveals that the integration of VDT into MABS matrices significantly enhances damping performance due to its superior compatibility and dispersion, as compared to those of Santoprene. The improvement in damping properties with the addition of soft elastomeric phases, although affecting tensile strength, opens new avenues for the application of these materials beyond hearing aids, including in automotive, aerospace, and consumer electronics industries where vibration damping is crucial. Moreover, the successful integration of basalt fibers not only enhances the composite’s mechanical performance and damping efficacy but also highlights the fibers sustainable and environmentally friendly nature. This integration is in alignment with the broader research objective of developing advanced materials that balance performance with ecological sustainability. Parallelly, this thesis develops predictive computational models based on viscoelastic theory, validated against experimental data, to elucidate the complex interactions within these novel polymer composites. These models provide a foundational tool for predicting material behavior and guiding the design of next-generation polymer blends with tailored viscoelastic properties for specific industrial applications.In summary, this work contributes to significant advancements in materials science by elucidating the mechanisms underlying enhanced damping in polymer composites through the synergistic use of compatibilizers and basalt fibers. It presents a pioneering approach to material design that not only has implications for the hearing aid industry but also for a broad spectrum of applications requiring advanced vibration damping solutions. The integration of computational modeling with experimental investigations further exemplifies a comprehensive methodology for accelerating the development and optimization of high-performance material systems

Enhancing vibration damping properties of MABS/VDT blends using SEBS-g-MAH as a compatibilizer

This investigation focuses on the enhancement of the damping properties of Methyl Methacrylate Acrylonitrile Butadiene Styrene (MABS) through the formulation of a specific blend with a styrene-based elastomer referred to as VDT, and with the incorporation of Ethylene Butylene Styrene grafted Maleic Anhydride (SEBS-g-MAH) as a compatibilizer. In contrast to traditional investigations that primarily focus on the mechanical rigidity, thermal conductivity, and electrical conductivity of materials, this research explores the enhancement of damping properties via the process of melt compounding. Using a twin-screw extruder in a precise melt-mixing process, a multiphase polymer blend is generated by including three different weight ratios (10, 20, and 30 wt.%) of VDT. Furthermore, in order to enhance the compatibility between MABS and VDT, three different weight percentages of SEBS-g-MAH (2, 4, and 6 wt.%) have been used in the blend. Tensile testing, laser confocal microscopy, dynamic mechanical analysis (DMA) and nuclear magnetic resonance (NMR), are used to thoroughly assess the compatibility and effectiveness of the blends. The results indicate that the damping performance of the blend increases in direct proportion to the amount of VDT. Conversely, the addition of SEBS-g-MAH has a non-monotonic effect: the inclusion of 4 wt.% SEBS-g-MAH leads to the most substantial improvements in both damping performance and tensile strength, exceeding the results obtained with 2 wt.% and 6 wt.% compatibilizer. The study highlights the need for carefully choosing the right wt.% of compatibilizers when aiming to formulate polymer blends with enhanced vibration dampening properties

Damping and sound absorption properties of polymer matrix composites: A review

This review article provides a comprehensive overview of fiber and nanoparticle reinforced polymer matrix composites (PMC) for their damping and sound absorption properties. It explains the mechanism of damping and sound absorption properties of the material as a first step. Further, the paper discusses the governing parameters of materials responsible for the variation of the material's damping and sound absorption properties. The performance of damping and sound absorption properties of different fibrous materials, including natural fibers, synthetic fibers, and different nanoparticles, including carbon nanotube, graphene nanotubes-based PMC are reviewed. The role of the interfacial region, density, fiber thickness, porosity, viscoelasticity, and friction on the damping and sound absorption properties has been discussed. The sound absorption properties of much denser, thicker, and more porous materials are higher than those of less dense, thinner, and less porous materials because of their higher polymerization. The damping performance of the PMC was observed to be increased with the decrease in the bonding of the interface region between fiber and matrix. The conclusion of this review provides several useful recommendations for the further development of PMC with the desired damping and sound absorption properties

Effects of SEBS-g-MAH addition on the vibration damping and mechanical properties of MABS/VDT blend

This study explored the influence of Maleic Anhydride-grafted Styrene Ethylene Butylene Styrene (SEBS-g-MAH) compatibilizer on the development of a novel kind of polymer blend to increase the vibration damping property of Methyl Methacrylate Acrylonitrile Butadiene Styrene (MABS) by compounding with a Styrene-based engineered elastomer (tradename VDT). Most of the research related to polymer blends has been focused on enhancing the material's stiffness, thermal or electrical conductivity by incorporating stiffer materials like glass fiber, graphene, CNT and so on. However, a limited amount of study has been done to investigate the possibility of increasing the damping property of the polymer by the use of melt compounding. Thus, a multiphase polymer blend was formulated by melt mixing in a twin screw extruder with three different weight ratios (10, 20, and 30 wt%) of VDT to enhance vibration damping with a minimum tradeoff in stiffness property. To improve the compatibility between MABS/VDT, SEBS-g-MAH was used with three different weight percentages (2, 4, and 6 wt%) and the effect of the compatibilizer was compared without it as well. The compatibility and effectiveness of the compatibilizer were investigated by studying their microstructure, tensile, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), light optical microscopy (LOM), and scanning electron microscopy (SEM) analysis and the samples were prepared by injection molding. The damping performance has been shown to improve as the weight percent of VDT in the blends increases. It was also found that the addition of 4 wt % of SEBS-g-MAH had the highest effect on the improvement of the damping performance and tensile strength compared to the additions of 2 wt % and 6 wt % of the compatibilizer

Novel approach for optimizing mechanical and damping performance of MABS composites reinforced with basalt fibers:An experimental study

The purpose of this research is to explore how basalt fibers, when compounded in specific proportions, impact the mechanical and damping attributes of methyl methacrylate acrylonitrile butadiene styrene (MABS). The fabrication process involved compounding basalt fibers in a twin-screw extruder at four distinct weight percentages: 5%, 10%, 15%, and 20%, with an MABS matrix. This study uniquely employs a comprehensive suite of characterization techniques including dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), X-ray microcomputed tomography (micro-CT), scanning electron microscopy (SEM), tensile tests, and density measurements to evaluate the composite's performance. The research significantly reveals that the integration of basalt fibers enhances the damping characteristics of MABS composites, as confirmed by DMA. Additionally, micro-CT scans provide unprecedented insights into the uniform distribution of basalt fibers within the MABS matrix, thereby elucidating the underlying mechanisms for the observed improvements. TGA data further bolsters the composite's thermal resilience, revealing its aptitude for high-temperature applications. Our findings establish a novel correlation between the basalt fiber weight percentage and the damping properties, revealing a non-monotonic relationship. This study thus not only augments the understanding of MABS based composites but also opens new avenues for the exploitation of basalt fibers in advanced composite materials, particularly in terms of their damping capabilities.</p