Polymers & Serendipity
Activities

Marcy Copeland, Yellow Medicine East High School, Granite Falls, MN
Dan Larson, Anoka High School, Anoka, MN
Dan Morton, Roseville Area High School, Roseville, MN

These lab activities are designed to accompany lessons in the role of serendipity in science. Students are usually impressed that they can prepare these polymers in a simple school lab:
To get students started, try this:

Have fun! (We did!)

An Introduction to Polymers

This is a partial list of common items that contain polymers.
Circle those that you have seen in the past seven days!

GARBAGE BAGS * FOAM CUPS * MILK JUGS * TOOTHPASTE TUBES * SANDWICH BAGS * FAST FOOD CONTAINERS * SHOE LACES * JUNK FOOD BAGS * 2-LITER BOTTLES * MOTOR OIL BOTTLES * PASTICWARE * SHAMPOO BOTTLES * SHOESTRING TIPS * FOOD WRAP * DISPOSABLE RAZORS * MARGARINE TUBS * DISPOSABLE DIAPERS * COFFEE STIRRERS * INSULATION * CAULKING * SHRINK WRAP * SILLY STRING * SILLY PUTTY * SLIME * CELLOPHANE TAPE * EPOXY GLUE * SUPERGLUE * DISH PANS * PLASTIC DISHES AND CUPS * TEFLON COATING * COMBS * TOOTHBRUSH * COUNTERTOPS * CARPET * TELEPHONE * FLOOR TILE * SYNTHETIC CLOTHING * SHOE SOLES * PAINT * TIRES * WINDSHIELD * SHOE BOX * DASHBOARD * FLOORMAT * VINYLTOP * BICYCLE HANDGRIPS * REFLECTORS * VINYL WALL COVERING * SUNGLASSES * COMPACT * CONTACT LENSES * HAIRSPRAY * LIPSTICK TUBES * RAINCOAT * PANTYHOSE * UMBRELLA * RUBBER GLOVES * NERF BALL * FRISBEE * SNORKLE * SWIM FINS * RAQUETBALL * TENNIS BALL * GUITAR STRINGS * BALLOONS * RUBBER BAND * CREDIT CARDS * PORTABLE RADIO * COMPUTERS * SAFETY GLASSES * FALSE TEETH * MUGS * LUNCH TRAY * FLOWER POT * MICROWAVE COOKWARE * LAWN CHAIR * ASTROTURF * VELCRO * FOOTBALL HELMET * HOCKEY PUCK * BUTTONS * ERASERS * THREAD * WIG * SURFBOARDS * PARACHUTE * SAIL * CORVETTE BODY * PLAYING CARDS * FLOOR WAX * RECORDS * AUDIO TAPES * COPMUTER DISCS * CDS * TYPEWRITER RIBBON * FLEA COLLAR * INDEX TABS * MODEL PLANES * JEWELRY * PACIFIER * BABY BOTTLE * FOAM RUBBER * PHOTO FILM * PHOTOGRAPHS * PLASTIC FLOWERS * MANNEQUINS * SCHOOL DESK * PROTRACTOR * RULER * OVERHEAD TRANSPARENCIES * SLIDES * TEST TUBE BRUSH * RUBBER TUBING
Can you name others?

PREPARATION OF COW PLASTIC

PREPARATION OF NITROCELLULOSE

PREPARATION OF NYLON 6-10

MATERIALS:

*Kits containing these compounds already prepared can be ordered from most chemical supply companies.

!! HAZARDS !!

Hexamethylenediamine and sebacoyl chloride are irritating to
the skin, eyes, and respiratory system.
Sodium hydroxide is caustic.
Hexane is extremely flammable as well as producing an irritating vapor.

PROCEDURE:

  1. Wearing gloves and goggles, prepare the hexamethylenediamine solution by dissolving 3.0 g of 1,6-diaminohexane and 1.0 g of NaOH in 50 mL of distilled water. (The hexamethylenediamine can be dispensed by placing the reagent bottle in hot water until sufficient solid has melted and can be decanted. mp = 39-40oC)
  2. Prepare the sebacoyl chloride solution by dissolving 1.5-2.0 mL sebacoyl chloride in 50 mL hexane.
  3. Place the hexamethylenediamine solution in a 250-mL beaker. Food coloring or phenolphathalein may be added to this lower phase to enhance the visibility of the liquid interface.
  4. Slowly pour the sebacoyl chloride solution as a second layer on top of the diamine solution, taking care to minimize agitation at the interface.
  5. With forceps, grasp the polymer film that forms at the interface of the two solutions and pull it carefully from the center of the beaker.
  6. Wind the polymer thread on a stirring rod.
  7. Wash the polymer thoroughly with water or ethanol before handling.

DISPOSAL:

Any remaining reactants should be mixed thoroughly to produce nylon. The solid nylon should be washed before being discarded in a solid waste container. Any remaining liquid should be discarded in a solvent waste container or should be neutralized with either sodium bisulfate (if basic) or sodium carbonate (if acidic) and flushed down the drain with water.

Click here for the story of the serendipitous discovery of nylon.

PREPARATION OF NYLON 66

PRODUCTION OF CUPRAMMONIUM RAYON

MATERIALS:

*MODIFICATIONS/SUBSTITUTIONS:
  1. CuSO4.5H2O can be purchased as root killer at a garden supply store.
  2. NaOH can be purchased as lye in grocery stores.
  3. Sulfuric acid is available from auto supply stores as battery acid. This solution is 4.8 M.
  4. Paper towels could be substituted for the shredded filter paper in this reaction.

EQUIPMENT:

!! HAZARDS !!

Avoid skin contact with all reagents.
> Use caution when making NaOH and H2SO4 solutions -- both are exothermic.
Avoid breathing NH3 vapors and work in a hood, if possible.
Goggles must be worn for this demonstration.

PROCEDURE:

  1. Dissolve 25.0 g of CuSO4.5H2O in 100 mL distilled water. Heat the water to accelerate the dissolving process.
  2. Dissolve 8.0 g of NaOH in 200 mL of distilled water.
  3. Mix the cooled NaOH solution with the copper sulfate solution. Collect the resultant gelatinous precipitate of Cu(OH)2 by filtration. Wash the precipitate with three 10-mL portions of distilled water. If using 11.0 cm filter paper, several filtrations will be required because of the large amount of precipitate produced.
  4. Measure 70-mL concentrated NH3 (aq) into a 250-mL Erlenmeyer flask. Shred four pieces of 11.0-cm filter paper. Add the Cu(OH)2 precipitate carefully along with the filter paper to this flask and stir. This should result in a deep purplish-blue solution of tetraaminecopper (II) hydroxide, referred to as Schweizer's reagent. Stopper the flask and stir periodically for 24 hours. Use a magnetic stirrer, if available.
  5. Take up the contents of the 250-mL Erlenmeyer flask in 10-mL increments in a 10-mL or 50-mL syringe. Squeeze out the contents into a 1000-mL beaker contained 300 mL of 1.6 M sulfuric acid. Be sure that the tip of the syringe or pipet is under the surface of the acid. A crude 'thread' should form.
  6. The clumps of threads can be washed free of the solution to show the white color of rayon.

DISPOSAL:

Flush the ammonia solution and the sulfuric acid solution down the drain with copious amounts of water. Dispose of rayon with solid waste.

The chemical structure of the product can be represented by the formula:

Click here for the story of the serendipitous discovery of rayon.

Silly Putty

Slime

'Sterno' (Canned Heat)