6533b834fe1ef96bd129e070

RESEARCH PRODUCT

Use of new hydroxytelechelic cis-1,4-polyisoprene (HTPI) in the synthesis of polyurethanes (PUs): Influence of isocyanate and chain extender natureand their equivalent ratios on the mechanical and thermal properties of PUs

subject

description

AbstractNew segmented polyurethanes (thermoplastic-elastomers) based on previously described hydroxytelechelic cis-1,4-polyisoprene (HTPI), miscellaneous isocyanates and chain extenders at various equivalent ratios were prepared by the classical one-shot method. The influence of the nature of isocyanate and chain extender, as well as their equivalent ratios, on the mechanical and thermal materials behavior was investigated. Thus, a comparative assessment of material properties was performed. Microphase separation of hard and soft segments was observed by DMTA, DSC and AFM. Moreover, according to Thermogravimetric Analysis (TGA), linear relationships depending on the isocyanate and chain extender nature were found between the weight loss (%) and the percentages of hard segments. A classification of thermal stability in terms of weight loss was established. With the aim of a thermo-mechanical comparative study, polyurethane elastomers based on HTPI and isocyanates without chain extender, were also synthesized.