Design and characterization of aromatic thermosetting copolyester resin for polymer matrix nanocomposites

aromatic thermosetting copolyester;nanocomposites;solid-state bonding;covetics

Bakir, Mete

关键词: aromatic thermosetting copolyester;    nanocomposites;    solid-state bonding;    covetics;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/104829/BAKIR-DISSERTATION-2019.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This study presents the development of multifunctional polymer nanocomposite systems utilizing aromatic thermosetting copolyester resin enriched with various forms of nanofiller particles. The molecular weight and crosslinking functionality of precursor oligomers during condensation polymerization reaction regulate thermal-mechanical properties of self-generated foam morphologies. Aluminum foam layered aromatic thermosetting copolyester foam sandwich structures demonstrate outstanding impact energy absorption characteristics. High-performance nanocomposite foams, incorporating homogenously distributed carbonaceous nanoparticles, display significantly improved thermophysical properties that outperform state-of-the-art configurations. Periodically-functionalized self-assembled shish-kebab structures develop within an aromatic resin dip-coated graphene fiber system through an epitaxial step-growth polymerization process. Graphene nanoplatelet particles conjugate with precursor oligomers during in situ polymerization process forming electrically percolated network domains which enable controllable conductivity for nanocomposite structures. The interfacial attachment mechanism between carbonaceous particles occurs via oxygen-bearing functional groups, which establishes covalent bonding with cure advancing crosslinking polymer network and modifies the glass transition region characteristics. The aromatic resin forms an interfacial liquid crystalline mesophase domain around graphene nanoplatelets, which uniquely displays a thermally reversible characteristic with shape memory effect. Self-luminescent dielectric silicon nanoparticles homogenously disperse into the aromatic matrix without neither losing their luminescent properties nor deteriorating chemical configuration of the polymer network. The neat and nanocomposite structures preserve their physical and chemical properties following direct exposure to aggressive environmental aging conditions. Bioactive nanofiller particles reinforced bionanocomposites hold a promise as a reconfigurable bone replacement material, for which interfacial coupling with nanoparticles enables more deformation tolerant nanocomposite matrix.The aromatic resin can afford high-temperature enabled solid-state dynamic covalent bond exchange reaction between two similar surfaces, which enables a reversible bonding scheme to develop multifunctional reconfigurable in-space architectures for deep-space missions. The bonding/debonding mechanism displays >50 times repeated cycles through predominantly cohesive failure along with high glass transition temperature and bonding strength required for relevant application requirements. The solid-state bonding concept can also be utilized to join similar/dissimilar polymer composites and metal articles permanently. Via controlled process time, temperature and pressure, aromatic resin displays relatively high bonding strengths viable from cryogenic temperatures to elevated temperatures. The bonding approach can be utilized to produce lightweight fuselage structures for spacecraft without necessitating additional joining mechanisms.Covetics are a novel class of carbon-metal nanomaterials for which in situ generated arc discharge during fabrication induces a chemical conversion reaction converting amorphous carbon to a crystalline graphitic structure which forms an intermetallic covalent bonding with host metal matrix. The covetics exhibit improved thermophysical properties as compared to their parent metals. We provide a comprehensive literature review on the covetics. Aluminum covetics demonstrate significantly improved corrosion potential relative to parent material with no carbon added. Both the hardness and the compressive strength of the aluminum covetic with carbon added are also improved. The carbon particles during covetics fabrication conditions induce structural modifications on intrinsic secondary phases which contribute to the observed changes in corrosion behavior and improvement in mechanical properties.