UHMWPE-layered silicate nanocomposites by in situ polymerization with tris(pyrazolyl)borate titanium/clay catalyst
| Autor: | Osvaldo L. Casagrande, Mariana Silva Beauvalet, Adriana C. A. Casagrande, Raquel Santos Mauler, Fabio Fernandes Mota, Bárbara C. Leal, Fernando Junges |
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| Rok vydání: | 2009 |
| Předmět: |
Materials science
Nanocomposite Flexural modulus UHMWPE Intercalation (chemistry) Methylaluminoxane chemistry.chemical_element clay General Chemistry Dynamic mechanical analysis chemistry.chemical_compound Chemical engineering chemistry nanocomposites Polymer chemistry Organoclay titanium catalyst In situ polymerization Titanium |
| Zdroj: | Journal of the Brazilian Chemical Society, Volume: 20, Issue: 3, Pages: 472-477, Published: 2009 Journal of the Brazilian Chemical Society v.20 n.3 2009 Journal of the Brazilian Chemical Society Sociedade Brasileira de Química (SBQ) instacron:SBQ |
| ISSN: | 0103-5053 |
| Popis: | Polyethylene-MMT nanocomposites were prepared by in situ polymerization methodology using TpMs*TiCl3 (1) intercalated into the gallery of Cloisite® 30B (C30B) using methylaluminoxane (MAO) as activator. From the powder X-ray diffraction (XRD) analysis it was observed that the basal spacing of the activated organoclay changes from 1.85 nm (2θ = 4.8) to 2.18 nm (2θ = 4.0) indicating that the intercalation of the titanium catalyst into the gallery took place. The catalytic system 1/C30B/MAO was active in the ethylene polymerization under different reaction conditions. The exfoliated morphology of the PE-MMT nanocomposite was further examined and confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The presence of exfoliated clay (5 wt.%) in the PE matrix confers better mechanical properties (flexural modulus and storage modulus) when compared with the ones displayed by the neat PE produced using exclusively 1. Nanocompósitos de polietileno-MMT foram preparados através da metodologia de polimerização in situ utilizando TpMs*TiCl3 (1) intercalado na galeria da Cloisite® 30B (C30B) e na presença de metilaluminoxano (MAO) como ativador. Através da análise de difração de raios-X (DRX) foi observado que o espaçamento basal da argila ativada muda de 1,85 nm (2θ = 4,8) para 2,18 nm (2θ = 4,0) indicando a ocorrência da intercalação do catalisador de titânio na galeria da argila. O sistema catalítico 1/C30B/MAO foi ativo na polimerização do etileno sob diferentes condições reacionais. A morfologia esfoliada do nanocompósito PE-MMT foi confirmada pela análise de difração de raios-X (DRX) e microscopia eletrônica de transmissão (MET). A presença de argila esfoliada (5% em peso) na matriz polimérica confere melhores propriedades mecânicas (módulo de flexão e módulo de armazenamento) quando comparada com aquelas apresentadas pelo polietileno puro produzido exclusivamente por 1. |
| Databáze: | OpenAIRE |
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