Over the last decade, carbon nanotubes (CNTs) are regarded as promising candidate for mechanical reinforcement of polymers. This thesis is mainly focused on developing Polymer/CNT composites using Single-walled carbon nanotubes (SWCNTs) as an effective mechanical reinforcement agent in the host polymer, Poly(methyl methacrylate) (PMMA). PMMA/CNT composites were fabricated in the form of gels and transparent films. In PMMA/CNT films, an interconnecting network of CNTs was observed in the scanning electron microscope after stretching the films at high temperature. The films showed improved tensile properties and it was observed that CNTs in PMMA have added flexibility to the originally brittle polymer. The addition of CNTs in the PMMA gel can be used to control the pore size in the composite gels. It was observed that as we increased the CNT concentration in PMMA, the pores sizes on the polymer surface reduced in dimensions leading to improved mechanical properties of the polymers.