Abstract
Research with the objective to find alternative raw materials for production of stickers are of great importance; as example of the tannin, that is a polifenol obtained of several renewable sources. This work aimed to evaluate the quality of a solution of tannin 50% as a modifier element in two synthetic resins with urea-formaldehyde with two concentration of free formaldehyde. The density, viscosity, time of gel formation and solids concentration were analysed for the modified sticker and for the modified resins or not. The data showed that the tannin change the properties of the modified commercial stickers, being the sticker with high concentration of free formol presented smaller viscosity and higher concentration of solids.
Key words
Tannin; urea-formaldehyde; adhesive.