Sintese de dispersões aquosas de poliuretano como proposta de substituição ao latex natural

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Products used as medical devices (gloves) or contraceptives (condoms) generally are made from natural latex due to its outstanding balance of physical properties. However, presence of proteins and chemical ingredients in its formulation can lead to human allergic reactions. Polyurethane has been used as a natural latex substitute, due to its good properties of strength and elasticity and non-allergenicity. Manufacturing process using polyurethanes generally uses organic solvent based solutions, that causes problems in terms of environmental and occupational healthy. In this work, formulations of polyurethane aqueous dispersions were studied as an alternative related to environmental subject and physical properties performance compared to naturallatex. Formulations using different ingredients (diisocyanates and polyols) and concentrations of hard and soft segments were done. Films were prepared and submitted to physical properties tests, infrared characterization, differential scanning calorimetry (DSC) and dynamical mechanical analysis (DMA). Results were comparatively evaluated with films from natural latex formulation. Through the analysis of DSC the relationship was verified inversely proportional between the molecular mass of the used poliol and the glass temperature transition (Tg) of the polyurethane. LIt was verified through the results of the physical properties that it is possible to obtain films originated of polyurethane aqueous dispersions with mechanical properties similar to the naturallatex ones (dispersion DAPU2), using a concentration of flexible (75,4%) superior to the hard segments (24,6%)

ASSUNTO(S)

poliuretanas elastomeros luvas camisa-de-venus latex polimeros soluveis em agua

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