Estudo do efeito da adição de poli(glicol etilênico-b-glicol propilênico) na formação de dispersões aquosas poliuretânicas à base de poli(glicol propilênico)

• Autor(a) principal: Almeida, Rosiléa Braga Luciano de
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/15782
• topic: Polyurethane aqueous dispersions; poly(propylene glycol); poly(ethylene glycol-co-propylene glycol); synthesis; characterization; dispersões aquosas poliuretânicas; poli(glicol propilênico); poli(glicol etilênico-co-glicol propilênico); síntese; caracterização; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA

Non-polluting and poly(urethane-urea) aqueous dispersions based on poly(propylene glycol) (PPG) and block copolymers of poly(ethylene glycol-b-propylene glycol) (EG-b-PG) containing 7% of ethylene glycol repeating units, were produced in an innovative way. The poly(urethane-urea)s were prepared, in two steps, by the prepolymer method. In the first step, anionomers, synthesized in bulk, based on EG-b-PG, PPG, dimethylolpropionic acid (DMPA) (anionomer sites generator) and isophorone diisocyanate (IPDI) were obtained. Still in the first step, the DMPA carboxylic groups were neutralized with triethylamine (TEA), generating the anionomer groups. In the second step, the anionomer prepolymer was dispersed in water under vigorous stirring and afterwards was chain extended with hydrazine. Different formulations were obtained by varying the NCO/OH ratio, and the proportions of PPG and EG-b-PG. Besides, poly(urethane-urea) aqueous dispersions with 40% and 50% of solid contents were obtained. The dispersions were evaluated in terms of their solid-contents, particle size and viscosity. The cast films, obtained from the dispersions concernig of water absorption, thermogravimetry (TG) and mechanical properties (stress and elongation at break). The films and monomers were characterized by infrared spectrometry (FTIR). The obtained dispersions were suitable when applied as for wood, metals and glass surfaces