CONICET | Buscador de Institutos y Recursos Humanos

The incorporation of an active compound to a polymeric matrix can provide distinctive functionalities as controlled release system of the active compound. The effect of additives on the morphological structure of a polymeric film is an important aspect in film characterization from a practical point of view, due to changes in permeability and mechanical properties. Polyurethane is one of the most popular materials for film-forming materials and they attract considerable attention since it combines a variety of functional components into a single material, which have the possibility of tailoring their properties by varying the polymer microstructure. These polymers are composed of alternating urethane and polyol segments formed in the reaction of organic diisocyanates with high molecular weight polyols and optionally with low molecular weight chain extenders. Microphase separation in this type of materials due to thermodynamic incompatibility between segments of various types and to formation of impermeable hard-segment domains dispersed in the rubbery softsegment matrix were often observed [2, 3]. The addition of an active compound to the polymeric matrix will produce micro and macroscopic changes in the film. On these changes, as well as on the action of the active compound, will depend the applicability of the film. If the relevant structural features are at a super-atomic level, from 1 to 100 nm, smallangle X-ray scattering (SAXS) is the most broadly used technique for studying them and particularly PU films morphology. The objective of this study is to investigate the effects of common antioxidant molecules, like butylated hydroxytoluene (BHT) and a-tocopherol (Toc), on the morphological structure of polyurethane (PU) films based on isophorone diisocyanate (IPDI) and polypropylene glycol (PPG1000) using SAXS.

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