The structural and mechanical properties of polysulfide-based polyurea

A series of polysulfide-based polyureas was synthesized, which were based on isophorone diisocyanate (IPDI), liquid polysulfide and 2,5-diamino-3,6-dimethylmercaptotoluene (Ethacure-300). The structure and mechanical properties of these elastomers were investigated using dynamic mechanical thermal analysis, differential scanning calorimetry, stress-strain analysis, water-resistance and oil-resistance tests. The results showed that there was phase segregation between soft and hard segments in polysulfide-based polyurea. With the increase in number-average relative molar mass and content of liquid polysulfide, the tensile strength decreased while the ultimate elongation increased. The effect of number-average relative molar mass of polysulfide and hard-segment content on oil resistance is also discussed. (C) 2003 Society of Chemical Industry.