The RPUFs have been fabricated from CMDI and
PPGs as a function of surfactant concentration with
an environmently friendly blowing agent (HFC
365mfc). Cream time, gel time, and tack-free time
increased with the addition of surfactant due to the
increased stability of reaction mixture and rising
bubbles.
Foam density and density distribution decreased
rapidly to a minimum at 0.5 pphp surfactant due to
the increased blowing efficiency in the presence of
surfactant. Surface tension of the foam rapidly
decreased to an asymptotic value at 2 pphp surfactant,
implying that the reaction mixture is saturated
at this concentration.
In accordance with the decreased surface tension,
cell size decreased and closed cell content increased
rapidly to constant values at low surfactant concentrations
(