Kinetic aspects of formation and hydrolysis of difurfurylidentriurea

Abstract

The urea and fulfural condensation, in the range of
urea:furfural molar relations from 1:1 to 1:4, produces the difurfurylidentriurea
regardless of the initial concentrations of the reactants. The result
is the same if the reaction is made in mass or in a dissolvent like water or
ethanol. A simplified kinetic study of the reaction of formation of the
difurfurilidentriurea (DFTU) in solution was carried out. Two solvents were
used: water and absolute ethanol. In both cases, we start from a homogeneous
system, but after a few minutes of initiating the reaction, a separation
of the product takes place and it becomes in a hard separable solid
product. That is why, the beginning of the reaction was studied and the
kinetic equation of the initial reaction rate was obtained in both cases. These
expressions differ from one system to another and the initial rate of reaction
is faster when the absolute ethanol is used as solvent. The hydrolysis
study of the DFTU was carried out at temperatures ranging between 30
and 80 °C . The results indicated that the maximum extent of the hydrolysis
increases with the temperature increment.