Flammability and Solubility of Natural
and Synthetic Fibers
Collaborative Class with Chemistry
Purpose: To determine
how natural and man-made fibers compare in strength, absorbency, resistance
to chemical damage, and flammability
Materials:
- Styrofoam cups
- Liquid bleach
- Water
- Oil
- Medicine dropper
- Mild acid ( lime juice, vinegar, or
lemon juice )
- 4 samples of natural fibers:
wool, cotton, linen, silk
- 6 samples of synthetic fibers:
rayon, polyester, nylon, acetate, ramie, acrylic
- Bunsen burner
- Tongs
- Marking pen
- Scissors
- Paper towel
- Rubber gloves
- Metric ruler
Safety: Wear safety
goggles at all times. Tie long hair back. Wear rubber gloves
when working with acids and bleach.
Procedure:
1. Record the color of each cloth.
2. Label six Styrofoam cups with
the names of the six cloth samples. Also, write the word bleach
on each cup.
3. Cut a piece of about 2 square
centimeters from each cloth. Put each piece in its cup.
4. Wearing rubber gloves, carefully
pour a small amount of bleach into each cup.
5. Label the six remaining cups with
the names of the six cloth samples and the word “acid”. Then pour
a small amount of the mild acid into each and repeat step 3.
6. Set the cups aside for 24 hours.
Meanwhile, proceed with steps 7-9.
7. Using the remaining samples of
clothe, attempt to tear each.
8. Place a drop of water on each
material. Note whether the water forms beads or is absorbed.
If the water is absorbed, record the rate of absorption.
9. Repeat step 8 using a drop of oil.
10. Obtain six more cloth samples.
Using tongs, burn each piece of material with a Bunsen burner and record
what you see.
11. After 24 hours, carefully pour
the liquids in the cups into the sink. Dry the samples with a
paper towel.
12. Record any color changes.
QUESTIONS
1. Which material held its color best
in bleach?
2. Which materials were least resistant
to chemical damage by bleach or mild acid?
3. Which material has the strongest fiber
or is hardest to tear?
4. Which materials are water repellant?
5. Which materials are flame repellant?
6. Which materials are most flammable?
7. Compare the natural and synthetic polymers’
strength, absorbency, and resistance to chemical damage.
8. Which material would you use to manufacture
a laboratory coat? A farmer’s overalls? A raincoat?
An auto mechanic’s shirt? A child’s pajamas?
Kim Greear
St. Paul High School
St. Paul VA
