Hibridos siloxano-polímero no comportamento hidrofilico de diferentes materiais
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Data
2009-05-12
Autores
Santos, Fabiane Raquel Oliveira dos [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
As mais recentes tecnologias requerem materiais com combinação de propriedades que não são encontradas nos materiais convencionais. Materiais híbridos foram preparados pelo processo sol-gel através da combinação de componentes orgânicos e inorgânicos e constituem uma alternativa para a produção de novos materiais multifuncionais, com uma larga faixa de aplicações. O objetivo deste trabalho foi avaliar as características mecânicas e hidrofilicidade de filmes híbridos siloxano-poliéter contendo ou não partículas de óxido de titânio antes e após fotocatálise sob irradiação no ultra-violeta. Numa primeira etapa, estudou-se a influência da quantidade de catalisador no tempo de gelatinização dos sois híbridos e a adição de polímero livre nas propriedades mecânicas, de aderência e molhabilidade de filmes híbridos do tipo siloxano-polietileno óxido (siloxano-PEO) com massa molar de 500 e 1900 g.mol-1. Posteriormente, analisou-se a influência da concentração de nanopartículas de titânia adicionada à matriz polimérica nas propriedades mecânicas, de aderência e molhabilidade. Avaliou-se a adesão utilizando-se a norma ASTM-D3359 e a molhabilidade do híbrido através de medidas de ângulo de contato em diferentes substratos recobertos: vidro, alumínio, acrílico e policarbonato. Medidas complementares de Microscopia Eletrônica de Varredura (MEV), Perfilometria, Ângulo de Contato e a Calorimetria Exploratória Diferencial (DSC) foram também efetuadas.
The more recent technologies require materials combining properties that are not found in convential materials. Hybrid materials prepared by sol-gel process from organic and inorganic components constitute one alternative to produce muntifunctional materials to be used in a wide range of applications. The main objective of this work was to evaluate the mechanic and hybrophilic characteristics of siloxane-polyether hybrid films containing (or not) titanium oxide particles before and after photocatalysis under ultraviolet irradiation. In a first step the influence of the catalitic compound amount on the gelation time of hybrid sols and the addition of free polyether on the mechanical adhesion and wet properties of siloxane-polyethylene oxide (siloxane-PEO) hybrid films (polymer molecular weight = 500 and 1900 g.mol-1) were evaluated. In the following, the influence of titanium oxide nanoparticles added to the polymer matrix on the mechanical, adhesion and wetting properties of films was studied. Adhesion was evaluated using the ASTM-D3359 technical norm while wetting was evaluated from contact angle measurements for films supported on glass, aluminum, polyacrilate and polycarbonate substrates. Complementary measurements of Eletronic Scanning Microscopy (ESM), perfilometry and Differential Scanning Calorimetry (DSC) were also performed.
The more recent technologies require materials combining properties that are not found in convential materials. Hybrid materials prepared by sol-gel process from organic and inorganic components constitute one alternative to produce muntifunctional materials to be used in a wide range of applications. The main objective of this work was to evaluate the mechanic and hybrophilic characteristics of siloxane-polyether hybrid films containing (or not) titanium oxide particles before and after photocatalysis under ultraviolet irradiation. In a first step the influence of the catalitic compound amount on the gelation time of hybrid sols and the addition of free polyether on the mechanical adhesion and wet properties of siloxane-polyethylene oxide (siloxane-PEO) hybrid films (polymer molecular weight = 500 and 1900 g.mol-1) were evaluated. In the following, the influence of titanium oxide nanoparticles added to the polymer matrix on the mechanical, adhesion and wetting properties of films was studied. Adhesion was evaluated using the ASTM-D3359 technical norm while wetting was evaluated from contact angle measurements for films supported on glass, aluminum, polyacrilate and polycarbonate substrates. Complementary measurements of Eletronic Scanning Microscopy (ESM), perfilometry and Differential Scanning Calorimetry (DSC) were also performed.
Descrição
Palavras-chave
Físico-química, Sol-gel, Polimeros, Híbridos
Como citar
SANTOS, Fabiane Raquel Oliveira dos. Hibridos siloxano-polímero no comportamento hidrofilico de diferentes materiais. 2009. 70. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Química, 2009.