The scale-up of the synthesis of high purity hydrogen-bonded supramolecular polymers is described. The synthesis involves functionalization of telechelic hydroxy-terminated poly(ethylenebutylene) with 2-ureido-4[1H]-pyrimidinone quadruple hydrogen-bonding groups via dibutyltindilaurate catalyzed urethane formation. A procedure with optimized reaction conditions was developed and applied on a 10dm(3) mini plant scale. The hydrogen-bonded supramolecular polymer was isolated in a yield of 86% (803 g) and the 2-ureido-4[1H]pyrimidinone functionalization of the end product was accurately determined with (FNMR)-F-19 to be 99.8% of the available hydroxy end groups in the telechelic hydroxy terminated poly(ethylenebutylene). Tensile tests showed that the product of the optimized large scale synthesis has better mechanical properties than the product of the unoptimized synthesis reported earlier. (C) 2003 Published by Elsevier Ltd.