The interest for the use of composite materials in the production of primary structures is strongly related to the ability of conferring to the polymers important functionalities, such as improved impact damage resistance and high electrical conductivity, allowing to overcome the structural limits of the same composites and extending their use for structural applications. Many studies have been carried out in this direction, obtaining important results, among which those related to the formulation of new nano-charged thermosetting resins with auto-repair functionality based on the supramolecular chemistry. For these materials, the self-healing activity is due to the presence, inside the epoxy matrix, of non-covalent interactions able to generate a supramolecular network which can heal the damaged sites. Different types of non-covalent interactions such as ionic, π-π stacking or hydrogen-bonding interactions, can be established. In particular, in this work, supramolecular hydrogen-bonding self-healing systems have been analyzed. For these systems, the hosting matrix has been toughened, through the addition of a rubber phase, to increase the chains mobility and to favor the activation of auto-repair mechanisms. Furthermore, in order to simultaneously impart electrical conductivity and auto-repair ability to the material, covalently functionalized Multi-Wall Carbon Nanotubes (MWCNTs) have been embedded in the polymer to transfer to it electrical conductivity and self-healing ability. The chemical groups chosen to functionalize the carbon nanofillers are Barbiturate and Thymine based ligands. The generation of the supramolecular network is based on the hydrogen bonds formed between the functional groups of the functionalized carbon nanofillers and those of the hosting matrix. The epoxy resin has been loaded with two different percentages of functionalized MWCNTs (0.5 and 2% by weight) and the obtained samples have shown good values of healing efficiency and electrical conductivity. The target of this investigation is to evaluate the thermal properties of the formulated self-healing carbon-based nanocomposites, by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) analysis. The formulated materials manifest thermal properties capable to fulfill the requirements of those applicable for structural applications, as they show thermal degradation temperatures higher than 350°C and high values of the Cure Degrees (higher than 90%).
Thermal investigation of supramolecular self-healing nanocomposite for structural applications
Elisa Calabrese;Carlo Naddeo;Marialuigia Raimondo;Liberata Guadagno;
2021-01-01
Abstract
The interest for the use of composite materials in the production of primary structures is strongly related to the ability of conferring to the polymers important functionalities, such as improved impact damage resistance and high electrical conductivity, allowing to overcome the structural limits of the same composites and extending their use for structural applications. Many studies have been carried out in this direction, obtaining important results, among which those related to the formulation of new nano-charged thermosetting resins with auto-repair functionality based on the supramolecular chemistry. For these materials, the self-healing activity is due to the presence, inside the epoxy matrix, of non-covalent interactions able to generate a supramolecular network which can heal the damaged sites. Different types of non-covalent interactions such as ionic, π-π stacking or hydrogen-bonding interactions, can be established. In particular, in this work, supramolecular hydrogen-bonding self-healing systems have been analyzed. For these systems, the hosting matrix has been toughened, through the addition of a rubber phase, to increase the chains mobility and to favor the activation of auto-repair mechanisms. Furthermore, in order to simultaneously impart electrical conductivity and auto-repair ability to the material, covalently functionalized Multi-Wall Carbon Nanotubes (MWCNTs) have been embedded in the polymer to transfer to it electrical conductivity and self-healing ability. The chemical groups chosen to functionalize the carbon nanofillers are Barbiturate and Thymine based ligands. The generation of the supramolecular network is based on the hydrogen bonds formed between the functional groups of the functionalized carbon nanofillers and those of the hosting matrix. The epoxy resin has been loaded with two different percentages of functionalized MWCNTs (0.5 and 2% by weight) and the obtained samples have shown good values of healing efficiency and electrical conductivity. The target of this investigation is to evaluate the thermal properties of the formulated self-healing carbon-based nanocomposites, by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) analysis. The formulated materials manifest thermal properties capable to fulfill the requirements of those applicable for structural applications, as they show thermal degradation temperatures higher than 350°C and high values of the Cure Degrees (higher than 90%).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
