Effect of Temperature on Tensile Curve of Polyaspartic Ester Polyurea and Its Activation Energy Analysis

Abstract

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 development of high‐strength, anticorrosive, and strongly adhesive polyaspartate polyurea coating suitable for pipeline spray repairs

“…The PAE molecule contains secondary amine functional groups and exhibits steric hindrance effects, effectively reducing the gel time of polyurea. 13 This overcomes the construction difficulties associated with the rapid curing of the first two generations of polyurea. Polyurea elastomer is composed of alternating flexible soft segments and rigid hard segments.…”

“…Its main components include hexamethylene diisocyanate (HDI) trimer and polyaspartic acid ester (PAE). The PAE molecule contains secondary amine functional groups and exhibits steric hindrance effects, effectively reducing the gel time of polyurea 13 . This overcomes the construction difficulties associated with the rapid curing of the first two generations of polyurea.…”

A novel isocyanate-free strategy towards preparation of polyurea by a ring-opening reaction

“…19 The mechanical properties of PAE are close to those of sprayed PUA, but the thermal stability and chemical resistance are not superior enough. 20–22 This phenomenon is probably because the bonding energy of the hydrogen bonds in PAE prepared using these special amine groups is lower than that of sprayed PUA, which has an effect on its thermal stability. 23 The service temperature of elastic PAE should be ≤80 °C for a long time, and rigid PAE can withstand a highest temperature of only 120 °C.…”