The reversible addition-fragmentation chain transfer (RAFT) radical polymerization of N-vinylcaprolactam (NVCL) was performed using either S-benzyl-S-(benzyl propionate) trithiocarbonate (CTA 1) or N, N-diethyl-S-(alpha,alpha'- dimethyl-alpha ''-acetic acid) dithiocarbamate (CTA 2) as a chain transfer agent (CTA). The polymerizations were controlled processes that yielded polymers with high conversion (>60%), controlled molecular weights that were close to the theoretical values and a narrow molecular weight distribution (minimal value: 1.13). The cloud point temperatures of poly(N-vinylcaprolactam) (PNVCL) were measured by turbidimetry and shifted to lower temperature and concentrations as the hydrophobicity of the end groups and the molecular weights of the polymers increased. (C) 2012 Elsevier Ltd. All rights reserved.