Sodium Silicate Polymer Lab

Sodium Silicate Polymer Lab

In science today we did a lab which tested a sodium silicate polymer. The purpose of this lab was to teach us some of the differences between this polymer, and the one we mad last week with sodium borate and glue. (See previous blog posts to read about that lab) The materials we used for the lab today were:

12 mL of Sodium Silicate solution

3 mL of Ethyl Alcohol

2 Small Beakers

1 Stirring Rod

1 Graduated Cylinder

Paper Towels

My hypothesis for this lab was that silicate chains will form from the sodium silicate and ethyl alcohol, creating a solid polymer. Because sodium silicate has sodium hydroxide in it, that acts as a strong base for the polymer. The cross-linking agent will be the ethyl alcohol, which will link the monomers in chains.

The procedure for this lab was pretty basic. First, measure 12 mL of sodium silicate solution with the graduated cylinder, and then pour it into one of the small beakers. Then clean the graduated cylinder and measure 3 mL of ethyl alcohol into it. Next, pour the 3 mL of ethyl alcohol into the other small beaker, (the one that doesn’t have the sodium silicate solution in it). When ready, pour the 3 mL of ethyl alcohol into the beaker with 12 mL of sodium silicate. Stir it with a stirring rod to create the polymer. Take it out and mold it into a ball. Drop it from a height to see if it bounces. Record different characteristics of the polymer.

Here is a drawing of the beaker of alcohol being added to the beaker of sodium silicate, creating a polymer:

Here is a diagram of the sodium silicate atoms and ethyl alcohol atoms:

The Sodium silicate has 1 atom of silicon and it is bonded to 4 oxygen atoms. Ethyl alcohol has only 2 carbon dioxide atoms.

After the polymer was made into a ball, my group tested the bounciness of the polymer. The silicate polymer was very bouncy. Even bouncier then the borax polymer. Here is a venn diagram of other similarities and differences between the silicate polymer and the sodium borate polymer:

The sodium silicate polymer smelled like nail polish, was hard, heavy, crumbly, compact and dry. The borax polymer was squishy, soft, smelled like glue, was light, slimy, stretchy, and slippery. Both of these polymers were made up of other monomers and they both had a cross-linking agent.

In the end, my hypothesis was supported because if sodium silicate is added to ethyl alcohol, then it will form a solid polymer because the atoms in the monomers bonded with each other in chains. As soon as the ethyl alcohol was added, a chemical reaction occurred and the solution became a polymer. Looking at this on a molecular level you can see that when sodium silicate and ethyl alcohol are put together, the ethyl groups replace oxygen atoms in the silicate ion. Then the silicate particles begin to link up with each other to form long chains. This gives you the hard, tough, bouncy polymer in the end.

This lab taught me a lot about how there are different types of polymers. In the previous lab, the end polymer was much unlike the polymer in this lab. If you start with different bases and you use different cross-linking agents, the end polymer has many possibilities. Now I know that if I need a strong polymer, I’ll use a strong substance like alcohol, but if I want a soft polymer, I’ll use something like borax.

If I could do anything differently, I would probably have done more tests to see the characteristics of the silicate polymer. I recorded a lot, but there still was more to observe and learn from this experiment.

If I could test anything differently, I would change the cross-linking agent of the experiment or the monomers of the experiment. I would choose substances, with a strong base level, to make the strongest polymer, and I would choose substances with the weakest base level, to make the weakest polymer. From this I would learn which monomers make the best and worst polymers.