Blocked Isocyanates and Their Usage in Plastic Coatings Applications
Similar trends can be seen in the results of stress/strain testing. As a system undergoes crosslinking, its tensile strength increases and its elongation will decrease. These results are shown in Figures 6 and 7. The DMP blocked control system does not reach maximum tensile strength or minimum elongation values until 135 deg C. The DIPA blocked system again appears very similar to the control in tensile strength development, but reaches minimum elongation values at a slightly lower temperature. However, this testing again shows improved crosslinking with the BEBA blocked system. Minimum elongation values are now seen at 120 deg C, while tensile strength values obtained at 125 deg C are of a level not seen by the DMP blocked system until 135 deg C.