Study on thermal property of Polyurethane-Urea elastomers prepared with different dianiline chain extenders

A number of polyurethane prepolymers based on polycaprolactone diol (CAPA), and 4, 4'-diphenyl methane diisocyanate(MDI) were synthesized and extended with different di anilines such as: 4,4'-Methylenebi s(2,6-diisopropylaniline) (M-DPA ), 4,4'Methylenebis(2-isopropyl-6-methyl aniline) (M-MIPA),4,4'-Methylenebis(2,6diethylaniline) (M-DEA),and 4,4'-Methylenebis(3-chloro-2,6-diethyl aniline) ( MCDEA). A method of using high melting point chain extenders in the synthesis of castable polyurethane Elastomer was applied in which the high melting point chain extenders was first dissolved in DMF before mixing with prepolymer. Using this method it was found possible to carry out a bulk polymerization in the normal PU reaction temperature range of 80-100C. IR spectroscopy was used to check the end of polymerization reaction and polymer characterization .Thermal properties were measured by means of DMTA, TGA and DSC and The effect of dianiline structure on the thermal properties of the cast films were studied and compared. It was found that the Thermal properties and thermal stabilities are affected by variation of dianiline molecular structure.