Cosmological models arising from generalized scalar field potentials

We find exact solutions for isotropic cosmological models containing a self -interacting scalar field possessing an interaction potential of a general class. In particular, we consider the combination of exponential potentials arising from a perturbation expansion in superstring theories. We also con sider a general class of potentials that give rise to power-law and polynom ial chaotic inflation, as well as the intermediate inflationary models; We compute the scalar and tensor perturbations produced in those models and us e the exact solutions obtained to examine the consistency of the first-orde r slow-roll expansion.