Influence of glass and sisal fibers on the cure kinetics of unsaturated polyester resin

Abstract

The effect of grinded glass and sisal fibers (25 vol%) on the cure kinetics of composites of unsaturated polyester resin (UPR) was investigated by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The DSC analysis was carried out at four different heating rates (5, 10, 20 and 40 °C/min), and the cure enthalpy and activation energy (E a ) were determined according to the Flynn-Wall-Ozawa (FWO) method. The results showed that increasing heating rates promoted reduced reaction times. The sisal fiber-containing composites exhibit higher activation energy values for the cure process in comparison with the neat polyester resin and the glass fiber composites. This can be due to the presence of polar groups in the sisal components, which physically interact with the polyester resin and retard the cure reaction. Hence, as sisal fiber retarded the cure reaction of the UPR resin, it is suggested that the use of natural fibers in polymer matrix composites can affect the cure kinetics of the polyester resin.

Thermal Degradation Kinetics of ZnO/polyester Nanocomposites

“…Nevertheless, some differences in the numerical values of the kinetic parameters are possible to appreciate. These differences with respect to Kissinger and Friedman are derived from the mathematical basis of both models, as previously described by other authors [ 15 , 18 , 19 ].…”

“…There are several methods for evaluating kinetic parameters through non isothermal thermogravimetric analysis, being the most common the model-fitting and the model-free [ 15 , 16 , 17 , 18 ]. The model-fitting approach employs different models to fit the experimental data.…”

“…However, not all model-free are isoconversional analysis. The typical case is the Kissinger model, which is a model-free but is not the isoconversional approach because it does not calculate activation energy at different constant extents of conversion but instead assumes constant activation energy [ 15 , 18 , 19 ]. The Friedman model is another isoconversional approach, just this model is a derivative method (Kissinger is integral method) and perhaps the most general of the derivative techniques [ 18 , 20 ].…”

Influence of tribological test on the global conversion of natural composites

“…This behavior suggests that the presence of fiber bundles could affect the development of curing. Some authors [39,40] have commented alteration on curing evolution of thermosetting composites systems, even when natural fibers are used as reinforcement. Musaceae fiber bundles could introduces the variations on the interfacial interactions respect to the matrix and introduce a catalytic effect on curing process and polymer chain network formation [41,42] .…”

Concreto Polimérico Reforzado con Fibras de Luffa

“…y Carneiro E.P., 2013); también se han utilizado fibras de bambú para mejorar la propiedades de tracción y la adhesión entre el agregado mineral y la resina polimérica, en base al poder antioxidante del bambú (Santos Delgado P. et al, 2012). Por otro lado, los grupos polares en la fibra natural de sisal interactúan físicamente con la resina poliéster y retardan la reacción de curado, lo cual puede permitir la manipulación durante la elaboración del concreto polimérico, el cual en promedio polimeriza en dos horas (Pistor V. et al, 2012).…”