Authors:Lisardo Núñez, F. Fraga López, L. Fraga Grueiro and J. A. Rodriguez Añón
From the peak reaction temperatures as a function of heating rate, the activation energies were obtained for a system consisting of an epoxy resin (Badgen=0) and a curing agent (isophorone diamine), using a Perkin Elmer DSC7 operated in the dynamic mode. At the same time, the Arrhenius law was used to calculate rate constants.
Authors:J. Añón, M. Añón, F. Fraga, J. Palacios and L. Regueira
Following a method based on the procedure given by Hubbardet al.  the calorific values of combustion in oxygen at 298.15 K were measured by static-bomb calorimetry for forest residues.
This waste mainly coming from mount reforestation, construction of firebreaks, etc., constitutes an important risk to originate
forest fire. From combustion experiments the mean calorific value of all species studied was found close to 19 000 kJ·kg−1, similar to calorific values of Municipal Waste. It can be concluded that this forest residues can be used as an additional
fuel to be added to Municipal Solid Waste in energy recovery plants. By doing this, energy, in this moment lost as abandoned
residues, can be recovered. At the same time the elimination of this waste minimizes the risk of forest fires. Our results
reasonably agree with literature values.
Authors:F. Fraga, T. Salgado, J. Rodríguez Añon and L. Nuñez Regueira
Mechanical behaviour play an important role in the election of an epoxidic formulation of well determined properties as it
has a marked influence on both structural and external factors.
Temperature and time strongly act on polymers properties owing to their viscoelastic nature.
Knowledge of the dynamic moduli and properties of polymeric materials is indispensable for the design of this materials. At
the same time, the influence of the temperature on polymers behaviour may be studied once the activation energy is known.
In this paper the different dynamic moduli and activation energy are measured using a Perkin Elmer DMA 7.
The relationships between the dynamic mechanical properties and the molecular weight of the polymers make possible the calculation
of the molecular weight.
Results reasonably agree with literature values.
Authors:F. Fraga, V. Soto, E. Rodríguez-Núñez, J. Martínez-Ageitos and V. Rodríguez
The study of the cure reaction of the epoxy
network diglycidyl ether of bisphenol A with amantidine is a useful tool to
characterize the industrial behaviour of this material. The total enthalpy
of reaction, the glass transition temperature and the partial enthalpies at
different cured temperatures have been determined using differential scanning
calorimetry in dynamic and isothermal mode. Two models, one based on chemical
kinetics and the other accounting for diffusion were used and compared with
experimental data. It can be seen that the inclusion of a diffusion factor
in the kinetic model is negligible.
Authors:F. Fraga, V. Soto, J. Blanco-Méndez, A. Luzardo-Alvarez, E. Rodríguez-Núñez, J. Martínez-Ageitos and M. Pérez
Knowledge of the the kinetic study of chitosan/genipin
allow to know the different effects that time and temperature have on the
cure reaction of the material.
The total enthalpy of reaction,
the glass transition temperature and the partial enthalpies have been determined
using DSC in dynamic mode. Two models, one based on chemical kinetics and
the other accounting for diffusion were used. The incorporation of the diffusion
factor in the second model allowed for the cure kinetics to be predicted the
whole range of conversion.