The dynamics of photoinduced charge separation, recombination and trapping are examined in a polymer blend photovoltaic material with ultrafast visible pump - infrared probe and time-resolved infrared spectroscopy. The carbonyl (C=O) stretch of methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM) is probed as a local vibrational reporter of the dynamics in a blend with a poly(p-phenylenevinylene) (PPV) -based conjugated polymer, CN-MEH-PPV. Following interfacial electron transfer, geminate electron - hole pair dissociation occurs on ultrafast timescales. Subsequent to this charge separation process, charge carriers become trapped on the microsecond timescale resulting in the formation of a distinct peak in the vibrational spectra corresponding to the anion of PCBM. The charge trapping dynamics correspond to the carrier lifetime of similar PPV-based polymer blends as reported in photocurrent transients from the literature.