Processes for preparing reinforced polymeric material and the materials formed therefrom are discussed herein. The processes generally include providing a polymeric matrix, providing single-wall carbon nanotubes (SWNT) or multiple-wall carbon nanotubes (MWNT), purifying by the nanotubes in a single step of dissolving a support and catalyst particles with an agent appropriate to the nature of the support to form a purified support, functionalising the purified support by reaction with an alkylamine to form a functionalized support, dispersing the nanotubes in the polymeric matrix by mixing in the molten state to form a mixture and optionally orienting the mixture by stretching.