Estudio cinético de la síntesis en masa de poliuretanos de 1,6-hexamtilen diisocianato y distintos glicoles de baja masa molecular

Abstract

Segmented polyurethanes (PU) present such versatility that allow us to design materials with varied mechanical properties, such as elasticity, resilience or toughness. The systematic study of the morphology-properties relationship of different blocks constituent of PU would allow us to understand their role in the mechanical properties of PU made up of distinct blocks. In this work we study the kinetics of bulk synthesis of different 1,6-hexamethylene diisocyanate PUs formed upon reaction with different low molecular weight glycols with varied chemical structure and composition: 1,4-butanediol (BD), ethylenglicol (EG), propylene glycol (PPgli), N-methyl diethanolamine (MDEA) and 3-methyl 1,5 pentanediol (3MPD). Some morphological aspects of the PU formed thereof are discussed. The exothermal behavior of the stoichiometric reactions follow the order MDEA > PPgli > EG > BD > 3MPD. The speed of reactions follows approximately the following order: MDEA > PPgli > BD > 3MPD > EG. The difference between the exothermal behavior and the curing kinetics appear to be promoted by the glycols viscosity as well as by the nature of formed PU.