Page 36 - 4th edition Nayi Udaan
P. 36
Khel-Khel me
Green Chemistry
Green Chemistr y
G reen chemistry also known as sustainable the use of as little energy and a few materials
chemistry involves designing chemical prod-
as possible and emphasizes using renewable
ucts and processes in ways that reduce or resources.
eliminate hazardous substances. This Lets learn to Turn Milk into Plastic!
includes re-evaluating which chemicals are Khel khel mein…
used, assessing chemical reactions, and (usually called casein plastic)
designing processes that result in less hazard- You can use it to make beads, ornaments, or
ous by-products and wastes. It encourages other items.
TIME REQUIRED called casein. When you heat milk and add an
acid (in our case vinegar), the casein mole-
Very Short (≤ 1 day) cules unfold and reorganize into a long chain.
Without enough vinegar the casein molecules
The word plastic is used to describe a material do not unfold well, making it difficult for
that can be moulded into many shapes. They them to link together into a polymer.
are all made up of molecules that are repeated
over and over again in a chain. These are The "best" recipe will have the highest yield
called polymers, and all plastics are polymers. (make the most plastic) for the smallest
Sometimes polymers are chains of just one amount of vinegar.
type of molecule, and in other cases polymers
are chains of different types of molecules. Materials and Equipment required:
Mugs or other heat-resistant cups (4); they
should all be identical, Masking tape, Pen or
permanent marker, Teaspoon measuring
spoon, White vinegar (at least 1 small bottle)
Milk (at least 12 cups); nonfat, 1%, 2%, and
whole milk will all work, Microwavable liquid
measuring cup; should be large enough to
hold 4 cups of mik, Spoons (4), Cotton cloth
The top image shows a polymer where the (12 squares, each 6 x 6 inches); cutting up old
monomers are just one type of molecule. The T-shirts works just fine, Rubber bands (4),
bottom image shows a polymer where the Clear plastic or glass drinking cups (4), each
monomers are made up of three different large enough, Wax paper (in 12 identical
molecules. In both polymers, the monomers pieces); each piece should be smaller than the
link in a repeating pattern. weighing surface of the kitchen scale, Paper
towels, molds, cookie cutters, food coloring,
Milk contains many molecules of a protein paint, glitter, permanent markers.
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