Here an in-depth analysis of reversible addition-fragmentation chain transfer (RAFT) polymerization kinetics is reported in order to provide better definition of poly(3-hexylthiophene) (P3HT) rod-coil block copolymers thru a more thorough understanding of the RAFT polymerization of the coil block. To this end, a new P3HT macroRAFT agent is synthesized and utilized to prepare rod-coil block copolymers with P3HT and poly(styrene), poly(tert-butylacrylate), and poly(4-vinylpyridine), and the RAFT polymerization kinetics of each system are fully detailed. This is achieved by a comprehensive analysis of characterization data from H-1 nuclear magnetic resonance spectroscopy, gel permeation chromatography, and matrix-assisted laser desorption ionization time of flight spectroscopy, which are used as complementary techniques in order to address difficulties in accurately characterizing the synthesized polymer systems. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3575-3585