Banca de QUALIFICAÇÃO: JULIANA MARTINS DA SILVA
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : JULIANA MARTINS DA SILVA
DATA : 24/11/2021
HORA: 14:00
LOCAL: Por participação remota
TÍTULO:
DEVELOPMENT OF SUSTAINABLE ADHESIVES BASED ON NATURAL RUBBER LATEX AND LIGNIN FOR APPLICATION IN SEVERAL SUBSTRATES
PÁGINAS: 51
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
RESUMO:
Sustainable materials have gained enormous attention for scientific and technological development due to their high abundance on Earth’s crust, economic viability and biodegradability, being a great alternative to replace the fossil-based materials. Natural rubber latex and lignin are structures obtained from natural sources with interesting properties for adhesive applications. However, the combination of these materials in adhesive applications is still little reported in the literature. Therefore, this work aims to develop a sustainable adhesive based on natural rubber latex with 5 wt % of lignin as an additive for applications on chemically distinct substrates, such as polypropylene (PP), aluminum (Al), glass and wood. To understand the latex-lignin interactions, three types of lignin (organosolv, alkali and Kraft) from different sources and extraction processes were investigated by atomic force microscopy (AFM). The results showed that the alkali lignin exhibited the best adhesion to the latex film possible due to the highest oxygenated group amount present in its chemical structure. The tensile tests of latex-lignin films also demonstrated that alkali lignin improved the mechanical properties of latex-based films, revealing that macroscopic properties are also driven by nanoscale interactions. Thus, the alkali lignin adhesives were selected to bond the various substrates mentioned. The PP, Al and glass joints bonded with alkali lignin adhesive revealed higher shear strength than neat latex bonded joints. Furthermore, the alkali lignin adhesive have potential for underwater applications as indicated by the shear strength results of PP and Al joints immediately after immersed in water. Therefore, the simple mixture of latex and lignin generates a sustainable and low-cost adhesive with differentiated adhesive properties and high commercial potential.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 052.991.506-52 - JULIANA DA SILVA BERNARDES - UNICAMP
Membro Titular - Examinador(a) Externo à Instituição - GEORGE JACKSON DE MORAES ROCHA - CNPEM
Membro Titular - Examinador(a) Externo à Instituição - CAMILA ALVES DE REZENDE - UNICAMP
Membro Suplente - Examinador(a) Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Suplente - Examinador(a) Externo ao Programa - 2347767 - MATHILDE JULIENNE GISELE CHAMPEAU
Membro Suplente - Examinador(a) Externo à Instituição - CAIO GOMIDE OTONI