Page 184 - Demo

Flinn Lab Activities and Demonstrations
Polymers—Demonstration Kits, continued
Mystery Nylon Factory—
Chemical Demonstration Kit
By: Jim and Julie Ealy, Retired
The Peddie School, Hightstown, NJ
Two solutions are poured together in a beaker. A paper clip is lowered into the solution. As the paper clip is withdrawn, almost by magic a very long strand of nylon is pulled from the beaker. A super demonstration to discuss polymer concepts. Demonstration Notes included.
Concepts: Polymerization, organic chemistry.
Time Required: 15 minutes
Chemicals Provided: Hexamethylenediamine/sodium hydroxide solu- tion, adipoyl chloride/hexane solution.
Note: Perform this demonstration in a fume hood or well-ventilated lab.
See free video at flinnsci.com.
Seeing Polymers in a New Light—
Demonstration Kit
By: The Flinn Staff
Discover the bright, rainbow-like color patterns that are created when objects made from polystyrene and other polymers are viewed between crossed polarizing filters. Brightly colored bands of different colors arise due to birefringence, making it possible to “see” areas in the struc- ture of a polymer where the molecules line up in an orderly, crystalline fashion. Crystalline regions may form when a hot polymer is forced through a narrow opening during injection molding or when a polymer is “stressed” by stretching or bending an object. Great applications- oriented demonstration—engineers use this tool to map out stress in plastic models of bridges! All the materials are reusable.
Concepts: Polymers, amorphous versus crystalline structure, polarized light, birefringence.
Time Required: 10 minutes
Materials Provided: Two polarizing filters, polystyrene “jewel” case, polyethylene bags, and craft sticks.
Sodium Alginate Polymer—
Chemical Demonstration Kit
By: The Flinn Staff
Sodium alginate is a natural “gummy-worm” polymer obtained from giant kelp and seaweed. The polymer is extremely hydrophilic or “water-loving” and dissolves in water to form a thick, viscous, smooth gel—perfect for use as a thickening agent in ice cream, yogurt, and other dairy products. Reacting sodium alginate solution with calcium or copper ions produces a smooth, flexible, semi-solid substance that precipitates from water in the form of—worms! The “worms” have the same texture and consistency as gummy candy. This fascinating demonstration shows what happens when long polymer chains are “tied together” via cross-linking. Be forewarned, your students may insist on “re-playing” this demonstration many times. That’s OK, because the polymer is a nontoxic food additive! Enough chemicals are provided to perform the demonstration as written seven times.
Concepts: Polymers, polymer gels, cross-linking, polysaccharides. Time Required: 15 minutes
Materials Provided: Calcium chloride solution, copper(II) chloride solution, sodium alginate, sodium chloride solution, jumbo pipets.
See free video at flinnsci.com.
1-800-452-1261
flinnsci.com
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Mystery Nylon Factory—Chemical Demonstration Kit AP2088
Catalog No.
Description
Price/Each
AP2088
Mystery Nylon Factory— Chemical Demonstration Kit
$31.30
Catalog No.
Description
Price/Each
AP7085
Seeing Polymers in a New Light—Demonstration Kit
$37.85
Seeing Polymers in a New Light—Demonstration Kit AP7085
Catalog No.
Description
Price/Each
AP7087
Sodium Alginate Polymer—Chemical Demonstration Kit
$32.20
POLYMERS—DEMONSTRATION KITS continued on next page.
Sodium Alginate Polymer—Chemical Demonstration Kit AP7087