Banca de DEFESA: LEONARDO DALSENO ANTONINO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LEONARDO DALSENO ANTONINO
DATE: 15/12/2022
TIME: 09:00
LOCAL: Bloco B - Campus de Santo André - Sala a ser definida - Composição híbrida
TITLE:

ADESIVO POLIURETANO TERMOATIVADO A PARTIR DE LIGNINA KRAFT MODIFICADA: RELAÇÃO ENTRE ORGANIZAÇÃO MOLECULAR E PROPRIEDADES MACROSCÓPICAS

PAGES: 153
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Polímeros, Aplicações
SUMMARY:

In the last decades, lignin, the second most abundant biopolymer on the planet, has been gaining prominence in the context of renewable raw materials, aiming to minimize dependence on fossil fuels. This natural polymer exhibits potential for application in several areas due to its industrial scale availability and its physicochemical properties. However, currently most of the world's lignin production is burned for electricity generation. One of the possibilities for the revaluation of this material is its use as a precursor in the polymers synthesis, such as polyurethanes (PU). PU are extremely versatile materials with a wide range of applications, adhesives being a major one. This work goal is the synthesis and characterization of thermoactivated PU adhesives from lignin. For this purpose, unmodified Kraft lignin and hydroxypropylated lignins (via two different routes) were reacted with diphenyl methylene diisocyanate (MDI). Castor oil was also employed as a polyol. A blocking agent (diisopropylamine - DIPA) was added to the systems. The synthesis methodology was based on the chemistry of blocked isocyanate and was divided into two steps: prepolymerization and curing. The determination of the ideal DIPA molar ratio was investigated in order to guarantee a lower degree of cross-linking during the prepolymerization step. The influences of DIPA and lignin concentration on pre-polymerization and curing kinetics were investigated using Temperature Modulated Optical Refractometry (TMOR) and Fourier-transform infrared spectroscopy (FTIR) techniques. Systems containing DIPA and lower lignin concentrations exhibited lower degrees of densification in both steps. DIPA also delayed the curing of the adhesives. In addition, lignins exhibited different reactivity. In the second stage of this project, the kinetics study will be concluded by rheological tests and the mechanical, thermomechanical and adhesive properties, as well as the morphology, of the adhesives will be investigated. These results will scientifically support the development of the lignin-based thermoactivated PU adhesives, thus promoting the revaluation of this biopolymer.

BANKING MEMBERS:
Presidente - Interno ao Programa - 1961116 - DEMETRIO JACKSON DOS SANTOS
Membro Titular - Examinador(a) Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Interno ao Programa - 1763443 - MARCIA APARECIDA DA SILVA SPINACE
Membro Titular - Examinador(a) Externo ao Programa - 1730526 - SUEL ERIC VIDOTTI
Membro Titular - Examinador(a) Externo à Instituição - CESAR LIBERATO PETZHOLD
Membro Suplente - Examinador(a) Interno ao Programa - 1671298 - RENATO ALTOBELLI ANTUNES
Membro Suplente - Examinador(a) Externo ao Programa - 2604737 - EVERALDO CARLOS VENANCIO
Membro Suplente - Examinador(a) Externo ao Programa - 1850090 - ANNE CRISTINE CHINELLATO
Membro Suplente - Examinador(a) Externo ao Programa - 1600860 - ALVARO TAKEO OMORI