Banca de DEFESA: ROGERIO RAMOS DE SOUSA JUNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ROGERIO RAMOS DE SOUSA JUNIOR
DATA : 10/12/2019
HORA: 09:00
LOCAL: Auditório, 8º andar, Bloco B, Campus SA da Fundação Universidade Federal do ABC, localizada na Avenida dos Estados, 5001, Santa Terezinha, Santo André, SP
TÍTULO:

Block copolymer-based nanostructured dielectric gels for artificial muscle applications

PÁGINAS: 150
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Polímeros, Aplicações
RESUMO:

In recent years there has been a growing number of studies involving so-called smart materials. An example is that of electroactive polymers, materials that show a mechanical response from an electrical stimulus, and due to their similarity to natural muscles, are known as artificial muscles. The main group of materials studied as artificial muscles are dielectric elastomers, which essentially must present properties such as low elastic modulus and high values of dielectric constant and stretchability. Currently, the main materials used in this area are acrylic elastomers, silicones and polyurethanes. In this context, there is the possibility of using styrenic block copolymers, materials of elastomeric behavior and which have as their main feature the ability to self-organize in ordered structures, allowing adjustments in mechanical, electrical and rheological properties. To reduce the elastic modulus, the use of these materials as artificial muscles occurs through the formation of nanostructured gels, by adding a low molecular weight compound that has selective interaction to the flexible segment of the copolymer. However, obtaining this type of gel also causes a reduction in their mechanical stability, due to the reduction of their physical cross-linking sites. Thus, the purpose of this work was to obtain nanostructured dielectric gels from the block copolymer SEBS with the addition of white mineral oil and, in order to improve mechanical stability, the a hydrogenated hydrocarbon resin was added. Subsequently, in order to increase the dielectric constant of the gels, lignin was introduced as an additive, an amorphous biopolymer with structure rich in functional groups such as phenols, carbonyls and hydroxyls. The materials obtained were characterized on their morphology and dielectric, rheological and mechanical behaviors. As main results, the addition of hydrocarbon resin caused an increase greater than 800% in tensile strength and greater than 1000% in elongation, without significantly changing the elastic modulus of the gels. And the addition of lignin, due to its polar structure, provided increases in the order of 50% in the dielectric constant of the gels. Finally the actuation behavior of the materials was verified by testing the effect of an electric stimulus. The gels presented an areal strain in the order of 200% under a relatively low electric field, demonstrating that these materials could eventually be used in artificial muscle applications.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Interno ao Programa - 2604128 - ALEXANDRE JOSE DE CASTRO LANFREDI
Membro Titular - Examinador(a) Interno ao Programa - 1961116 - DEMETRIO JACKSON DOS SANTOS
Membro Titular - Examinador(a) Externo ao Programa - 1730526 - SUEL ERIC VIDOTTI
Membro Titular - Examinador(a) Externo à Instituição - RICARDO JORGE ESPANHOL ANDRADE - UPM
Membro Suplente - Examinador(a) Interno ao Programa - 1763443 - MARCIA APARECIDA DA SILVA SPINACE
Membro Suplente - Examinador(a) Externo ao Programa - 2352281 - LIGIA PASSOS MAIA
Membro Suplente - Examinador(a) Externo à Instituição - BALTUS CORNELIUS BONSE - FEI
Membro Suplente - Examinador(a) Externo à Instituição - CARLOS HENRIQUE SCURACCHIO - UFSCAR