The activation energy was calculated for the raw material
and for the as-spun membranes before and after
cross-linking with GA (Table 1). The values show that
dissolution and processing conditions does not affect the
thermal degradation of the material. It was previously reported
that the [25] thermal activation energy for gelatin is
between 175 and 275 kJ.mol1
, the difference to the present
investigation being attributed to the gelatin source, i.e.
animal or fish gelatin, and molecular weight. After crosslinking,
a decrease of Eact was observed in both transition
stages of the electrospun membranes (Table 1), which was
probably due to random scission of polymer chains [25]. GA
cross-linking of gelatin promotes water insoluble enzymes,
cross-linking being associated with more rigid molecules
with less ordered structures. Protein–protein interaction is,
therefore, apparently affected by chemical cross-linking,
and decreases the thermal stability of gelatin electrospun
membranes. During heating, the initially ordered structure
of the samples is gradually destroyed after breaking of
inter- and intra-molecular hydrogen bonds, which are
responsible for the maintenance of the polymeric chain
[25,27].
The activation energy was calculated for the raw materialand for the as-spun membranes before and aftercross-linking with GA (Table 1). The values show thatdissolution and processing conditions does not affect thethermal degradation of the material. It was previously reportedthat the [25] thermal activation energy for gelatin isbetween 175 and 275 kJ.mol1, the difference to the presentinvestigation being attributed to the gelatin source, i.e.animal or fish gelatin, and molecular weight. After crosslinking,a decrease of Eact was observed in both transitionstages of the electrospun membranes (Table 1), which wasprobably due to random scission of polymer chains [25]. GAcross-linking of gelatin promotes water insoluble enzymes,cross-linking being associated with more rigid moleculeswith less ordered structures. Protein–protein interaction is,therefore, apparently affected by chemical cross-linking,and decreases the thermal stability of gelatin electrospunmembranes. During heating, the initially ordered structureof the samples is gradually destroyed after breaking ofinter- and intra-molecular hydrogen bonds, which areresponsible for the maintenance of the polymeric chain[25,27].
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