Synthesis of Linear Polyurethanes. I. Experiments

MARA POLO; MARISA SPONTÓN; FRANKLIN JARAMILLO; DIANA ESTENOZ; GREGORIO MEIRA

Simposio; XII Simposio Argentino de Polímeros 2017 (SAP); 2017

This work investigates the 2-steps synthesis of linear segmented thermoplastic polyurethanes (STPUs). The reactions involved methylene diphenyl diisocyanate (MDI), two different poly(tetramethylene oxide) (PTMO) macrodiols, and 1,4-butanediol (BD) as chain extender. The syntheses were carried out in two stages. In the first (Prepolymerization) stage, a low molar mass polymer was obtained by reaction between the macrodiol and an excess of diisocyanate. In the second (Finishing) stage, the system was diluted with THF, and thechain extender was added to increase chain length. The reaction was analyzed by FTIR, 1H-NMR and size exclusion chromatography (SEC). Measurements by 1H-NMR enabled to follow the global concentrations of isocyanate and urethane groups, the extent of reaction and the number-average number of structural unitsalong the Prepolymerization and Finishing stages.