Gelatin as a Physically Cross-linked Elastomer

You are shipwrecked on a desert island. You find some bushes that have a sticky sap. You also find the island has all kinds of minerals. How do you get off the island  

Ordinary gelatin is made from the skins of animals by a partial hydrolysis of their collagen, an important type of protein (A1,A2). At home, a crude type of gelatin can be prepared from the broth of cooked meats and fowl this material also frequently gels on cooling. 

By observing the depth of indentation of a sphere into the surface of gelatin, indentation modulus is easily determined. The indentation modulus yields its close relative. Young s modulus. The cross-link density and thus the number of hydrogen bonds (simple physical cross-links) are readily determined by treating the gelatin as a hydrogen-bonded elastomer. 

Young s modulus may l e determined by indentation using the Hertz (A6) equation  

The ball indentation experiment is the scientific analogue of pressing on an object with one s thumb to determine hardness. The less the indentation, the higher the modulus. 

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APPENDIX 9.1 GELATIN AS A PHYSICALLY CROSS-LINKED ELASTOMER... 

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