부산대학교 도서관

The aim of this work is to describe how rheological techniques can be used to investigate the morphology of blends of two immiscible elastomers, namely natural rubber (NR) and polybutadiene (PB). Rheological characterization in the melt was performed. In oscillatory shear flow at low frequencies and low volume fractions of the minor phase, the storage modulus shows an excess of elasticity that increases with the dispersed phase content. At higher concentration of the minor phase, the elasticity decreases in relation to the morphology. The rheological tests in the solid state were carried out. The evolution of storage modulus of blends with the composition at the temperature of crystallization of polybutadiene is related to the morphology of this elastomer. The phenomenon of “fractionated crystallization” is evoked to explain the structure of polybutadiene in the NR/PB blends. Samples were also ultra cryo-microtomed and then analyzed by TEM to confirm the results obtained by rheology. The superposition of the three procedures gives a nice picture of unfilled and uncured NR/PB blends. [ABSTRACT FROM AUTHOR]