Which would be expected to have a lower softening point an a

Which would be expected to have a lower softening point, an asphalt directly obtained from vacuum fractionation, or the same asphalt, but which is later subjected to air blowing? Briefly explain.

Solution

The asphalt directly obtained from vacuum fractionation is expected to have a lower softening point.

The same asphalt, but which is later subjected to air blowing in the presence of some catalyst amounts will harden and the will lead to a higher softening point. This will cause the condensation polymerization reactions inside the asphalt and harden the asphalt.