the chemistry of glue, goats milk is dairy and more

[Guest guest]

Yes goats milk is dairy, but it is missing the chemical Casein which makes

glue, which makes glue in our system some information and there's other

products like gluten this makes glue in our system. Hear some basic

information on

glue.

The Chemistry of Glue

Teacher Note: Just about everyone is familiar with milk, but few of us are

aware of its chemical uses. If milk is not refrigerated it sours due to the

production of lactic acid by bacteria. The acid in turn causes milk to curdle.

The curds contain the solid, precipitate casein. Casein is a key ingredient

in plastics, synthetic fibers, and glue. In the lab, the curdling process can

be speeded up by the addition of an acid to take the place of the lactic

acid. You will use vinegar (acetic acid) to produce the curds of casein. Later,

you will neutralize the vinegar using sodium bicarbonate (baking soda). The

filtering takes a long time. You will need to let this sit overnight before the

students can get the curds. You could, however, use several layers of cheese

cloth in place of the filter paper to speed up the process. Also, use skim

milk - the fat in whole milk makes for slippery glue.

MATERIALS: Skim milk, vinegar (acetic acid) CH3COOH, Sodium Bicarbonate

(baking soda) NaHCO3, water, beaker, graduate, stirring sticks, filter paper or

cheese cloth, funnel, tongs, hot plate.

PROCEDURE:

1. Pour about 50ml of skim milk into a beaker. Add 10ml of vinegar (acetic

acid).

2. Heat slowly on a hot plate with constant stirring. As soon as the milk

begins to curd, remove the beaker from the heat. Continue to stir for about one

minute.

3. Filter mixture.

4. After the liquid has been drained, scrape the curds from the filter paper

into the beaker.

5. Add a little water and .5g of sodium bicarbonate (baking soda). Stir the

mixture until it is creamy smooth. If it still bubbles, add a little more

baking soda to completely neutralize the vinegar.

6. Use your glue to bond two 2 inch squares of scrap paper together. Staple

your sample to the upper left-hand corner of this lab

Jeff el

10360 Pine Lakes Blvd

North Fort Myers, Fl 33903

http://www.msprotocols.com/