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Melamine cyanurate served as a reactive flame retardant crosslinker for chloroprene rubbers.

The influence of ambient temperature on the tensile stress-strain curve of polyaspartic ester polyurea (PAE-PU) was investigated to discuss the yield and breakage mechanism of tensile deformation. Temperature has a significant effect on the tensile stress-strain curve of PAE-PU. At low temperature (27, 40 °C), it shows obvious yield and forced high elasticity. After the temperature exceeds 80 °C, the yield phenomenon disappears and shows high elasticity of rubber: the strain energy and breakage energy are significantly reduced. The yield activation energy of PAE-PU was calculated by yield strain time at different temperatures. It was found that the yield activation energy decreased with the increase of tensile rate. When the tensile rate is 500mm/min, among the activation energies calculated by breakage strength, yield strength and Young’s modulus at different temperatures, the ordinary elastic deformation activation energy is higher, while the yield and breakage activation energy are close and lower. The latter two are close to the hydrogen bond energy and one order of magnitude lower than the chemical bond energy of molecular chain.

The tensile properties of polyurethane are related to the microstructure due to the change of hydrogen bond and hard segment domains at different temperature and velocity. In this paper, the structure and glass transition before and after tensile breakage of polyaspartate (PAE) based polyurea (PU) coatings were analyzed by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and tensile strain energy of stress - strain curve. The PAE-PU has not changed its allophanoyl (C=O in urea) and amino (N-H) hydrogen bond content apparently by the comparison of their IR absorption peak height. The PAE-PU has two glass transition temperatures related to soft and hard segments, which move to greater distance after tension. Moreover, the Enthalpy relaxation accompanied by hard segment glass transition almost disappears after tensile break. The dependency of tensile curve of PAE-PU on tensile rate at the same temperature is different from ordinary polymer materials; i.e.it has greatest yielding, strength and strain energy at medial rate of 100mm/min rather than higher ones.