Influence of Nano-Organomontmorillonite on the Viscoelasticity of the Poly(trimethylene terephthalate)/ Glass Fiber/Organomontmorillonite Hybrid Nanocomposites Materials

摘要

The influences of organically modified montmorillonite (OMMT) on the viscoelasticity of poly(trimethylene ter-ephthalate)/glass fiber/OMMT (PTT/GF/OMMT) hybrid nanocomposite materials at liquid, elastic and glassy states, respectively, were investigated by using the rotational rheometer and dynamic mechanical analyzer (DMA). The viscoelasticity results suggest that OMMT has many important influences on the structure, modulus and toughness of the hybrid nanocomposite materials. At melton state, the shear-thinning phenomena of the hybrid composite melts become remarkable with increasing OMMT content. At low frequency, the shear storage modulus (G) and shear loss modulus (G'') of the melts increase with increasing OMMT content. The melt's elastic response increases by OMMT, and OMMT improves the creep resistance of the melts; in addition, the stress relaxation of the hybrid composite melts become slow with increasing OMMT content, and the stress leavings becomes much higher with increasing OMMT content. At glassy state, the storage modulus of the hybrid nanocomposites increases with increasing OMMT content, while the materials' loss modulus increases first and then decreases with increasing OMMT content; therefore, OMMT nano-sheets have reinforcement effect on the composites, and it also has definite toughening effect on the hybrid composite when the OMMT content is no >2 wt%. At rubbery state, the hybrid composites show lower decreasing storage modulus but have lower cold-crystallization ability than that of pure PTT and PTT/GF composite.