Electron Beam Curing Of Methacrylated Gelatin: Analytical Characterization And Properties

Gelatin consists of a mixture of water-soluble proteins ranging from about 10000 to several
100000 Dalton. It is obtained from its naturally occurring parent protein, collagen, by chemical
and thermal hydrolysis. Aqueous gelatin solutions are well-known for their capability of forming
elastic gels. Due to its nontoxic nature, gelatin is widely used in food, pharmaceutical and
photographic products, and also as a protective colloid for prevention of coalescence.
Gelatin shows excellent film forming properties. Such films were found to have a very low
oxygen permeability. However, gelatin is soluble in warm water which is a considerable drawback
for the practical use of gelatin coatings, for example in food packaging applications. If
one succeeds to overcome the solubility of the gelatin by chemical cross-linking, one may get
polymer-like biodegradable coatings with a superior barrier behavior against oxygen and with
high resistance against boiling water.

This study describes the cross-linking of newly developed methacrylated gelatins by electron
beam curing. The gelatin coatings can also be cured by UV irradiation if a suitable water soluble
photoinitiator is used. However, the photoinitiator is not chemically incorporated into the
polymer network formed and may migrate out of the coating. In respect to this property, EB
curing is to be preferred.