After one propagation step
, the whole graph is monitored so [[gamma].
followed by a propagation step
, in which the addition of an epoxy/anhydride couple (M) to the growing chain takes place.
Therefore some initiative has to be introduced the enable the propagation step
to be interrupted and able to separate the wavelength eventually (Figure 4 (b).
In the propagation step
, peroxyl radical is able to abstract H from another fatty acid, resulting lipid hydroperoxide or peroxide (LOOH).
The propagation step
involves H: shift and :CH3 group shift to form tertiary carbenium ion which is more stable and abundantly available during propagation.
c] is reached, the propagation step
is no longer favoured, and the reverse reaction dominates.
Once the free radical process is initiated, abstraction of the most labile hydrogen atom in the polymer by alkylperoxy radical predominates in the propagation step
Almost all thermal oxidations of vinyl polymers at moderate temperatures are postulated to involve the hydroperoxide radical in the propagation step
of the degradation.
As the kinetic model will be applied in the conversion range previous to vitrification, the specific rate constant for the propagation step
will be considered independent of conversion.
Apparently, the influence on the termination and initiation steps outweighs that on the propagation step
The above results indicate that the sharper the notch the less effect the thermal history has on the fracture energy, or in other words, the crack initiation step is more sensitive to the thermal treatment used in the foaming procedure than the crack propagation step
Those radicals react with a nearby monomer M beginning the radical chain reaction with P(1), which continues through propagation steps
that generate longer chains P(i).