Banca de DEFESA: ROGER SOUZA DE OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ROGER SOUZA DE OLIVEIRA
DATA : 26/06/2020
HORA: 09:00
LOCAL: Instituto de Química
TÍTULO:

Coordination compounds: a strategy for acting as catalysts in the polymerization of ethylene.

PALAVRAS-CHAVES:

Polyethylene, polymer, catalyst, graphene

PÁGINAS: 167
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Campos de Coordenação
RESUMO:

The polyethylene is currently one of the most used materials by modern society, since it started the so-called “Plastic Age”, early last century. There are various different types of polyethylene, with different properties, that lead to different applications, which makes this material quite versatile. This differentiation basically due to the polyethylene production, considering initiators, catalytic systems and industrial conditions.

Over time the ethylene polymerization process has undergone several modifications. Early processes using radical species as initiators, requiring high pressures and temperatures, were replaced by coordination compounds, on a catalytic system that made it possible to use much milder reaction conditions and obtaining a better quality polymer.

The first catalytic system of great success in industrial scale, they were Ziegler-Natta’s catalysts, made in the 50’s. With them it was possible get high density polyethylenes, with linear chain, without ramification as obtained with radical initiators. From knowledge obtained from this system obtained from this system, uniting coordination compounds containing transition metals and organometallic compounds, mainly alkylaluminiuns, it was possible develop various new catalyst called metalocenes.

In this job were used a series of catalysts, as the zirconocene (ZDC) which contains zirconium as a metal center, and a series of catalysts type 2,6-bis(imino)pyridine (MIpy), which contains iron or cobalt in its coordination realm. The catalysts were used singly or in combination and in all cases was utilized methylaluminoxane (MAO), to generate the catalytically active species to act on polymerization.

Further of homogeneous catalysis, the system with the heterogenation of the catalysts was used, using a carrier, changing the polyethylene’s properties. The carrier used was reduced graphene, a allotropic form of carbon, recently discovered. It stands out due to its excellent electrical and thermal properties, fact that considerably changes polyethylene, getting a product with increasingly comprehensive applications.

MEMBROS DA BANCA:
Interno - 1756798 - ELISANGELA FABIANA BOFFO
Interno - 413299 - ZENIS NOVAIS DA ROCHA
Externo ao Programa - 2474717 - KLEBER QUEIROZ FERREIRA
Externo ao Programa - 2494172 - LILIAN MARIA TOSTA SIMPLICIO RODRIGUES
Externo à Instituição - EMERSON ANDRADE SALES - UPD