Metal oxides were embedded in multi-walled carbon nanotubes (MWCNTs) and irradiated with microwaves to synthesize metal matrix composites (MMCs). Under irradiation, the MWCNTs’ high blackbody emissivity generated temperatures above 1000 °C, promoting solid-state reduction of the metal oxides. Only copper showed high solubility for MWCNTs. Nanorods for polymer matrix composites (PMCs) were generated by irradiating pure MWCNTs. The PMCs were prepared with 1.0, 0.5, and 0.2 wt% AlN nanorods in bisphenol E cyanate ester (BECy) monomer. The composites were analyzed by DSC, TGA, DMA, and TMA instrumentation. High magnification SEM confirmed good dispersion of the nanorods in the polymer matrix.