Polímero biocompatível e biodegradável como plastificante para nitrocelulose: possibilidade de aplicação em esmalte de unha

Abstract

This work investigated the use of poly(Ɛ-caprolactone) as a plasticizer for nitrocellulose nail varnish application. The glass transition temperature (Tg) was studied as a condition related to the formation of miscible polymer blends because it is directly related to the addition of plasticizers in nail polish due to the fragile behavior of nitrocellulose. A total of eight blends were prepared from commercial nitrocellulose and two other blends from nitrocellulose synthesized in the laboratory through reaction between cotton and a mixture of H2SO4/HNO3. The changes in the thermo-mechanical properties of the blends were determined by Dynamic-Mechanical Analysis (DMA) – Material Pocket. Tg of commercial nitrocellulose and poly(Ɛ-caprolactone) were 68,0 and -52,0 °C, respectively, and agreed with the values reported in the literature. The Tg of the blends was easily determined from tan curve, since it showed a single peak between the Tg values of isolated polymers, indicating good miscibility between them, also confirmed by the Hansen solubility parameter. The synthesized nitrocellulose, blends and poly(Ɛ-caprolactone) were also analyzed by IR spectroscopy, which indicated the reaction success and the presence of each polymer in the blends. Finally, the Tg of the blends exhibited a logarithmic dependence on the poly(Ɛ-caprolactone) content, decreasing as the poly(Ɛ-caprolactone) content increased, indicating that NC plasticization has occurred.