THERMOMECHANICAL PROPERTIES OF TOUGHENED PHENOLIC RESOL RESIN

Abstract

Changes in thermal and mechanical properties of polyvinylbutyral (PVB) modified phenolic resole resin were studied. The DSC and TGA studies show that an increase in PVB content results in a reduced thermal stability at temperatures above 360 °C, but causes little change in thermal properties at temperatures below 300 °C. The izod impact strength of cast moulded resin is maximum with PVB content of 10 phr. The PVB modified phenolic system possessed discrete spheres of PVB evenly dispersed in a phenolic resin matrix at low thermoplastic content. However, at higher concentrations, phase inversion resulted, and the morphology consisted of discrete spheres of phenolic resin embedded in a PVB matrix. A decreased in hydroxyl peak intensities (3497-3362 cm -1 ) and broadening of ether peak (1275-1200 cm -1 ) are more prominent when compared with the unmodified blend, due to cure reactions and with the increased amount of PVB in the blend film.