Faces in the Molecular Sciences - Polymer Module
Rubber, Plastic, Fiber - Procedure
A. Elongation at Break Test
Lay the yard stick across the table
Measure the length of the rubber, plastic, and fiber samples to be tested, and record
them in your laboratory notebook.
Using two pair of needle-nosed pliers, grasp the sample at each end. Hold one end of the
sample at "0" on the yard stick. Slowly stretch the other end of the sample as far as it
will stretch, until the sample breaks. This is best done with two students, each holding the
sample at one end. Note how far you had stretched the sample when it broke. Record this in your
laboratory notebook.
Using the formula below, calculate percent elongation at the point of breaking. Record this
information in your laboratory notebook.
B. Reversible Elongation Test
Lay the yard stick across the table
Measure the length of the rubber, plastic, and fiber samples to be tested, and record
them in your laboratory notebook.
Using two pair of needle-nosed pliers, grasp the sample at each end. Hold one end of the
sample at "0" on the yard stick. Slowly stretch the other end of the sample in small
increments. After each increment, release the sample to see if it will return to its original
length. This is best done with two students, each holding the
sample at one end. Note the longest distance you can stretch the sample without having the
sample stretch permanently. Record this in your laboratory notebook.
Using the formula below, calculate percent reversible elongation. Record this
information in your laboratory notebook.
