Sodium Silicate Polymer Lab Investigation

Background: In my previous blog, I talked about what polymers were. They are basically long strings of molecules.

Chemical formulas:

Na2Si3O7 is sodium silicate but the sodium silicate solution is in H2O.

NaOH is sodium hydroxide and is found in sodium silicate solution. It is a very strong base.
SiO2 is silicon dioxide.

CH3CH2OH is ethyl alcohol.

• When the ethyl alcohol is added to the sodium silicate solution, 2 ethyl atoms, or CHCH, replace 2 oxygen atoms from the sodium silicate.

Materials:

• 12 mL sodium silicate solution
• 3 mL ethyl alcohol 
• 2 small beakers (150 mL to 250 mL) 
• stirring rod 
• 2 funnels
• 1 graduated cylinder
• water
• paper towels

Procedure: First, measure 12 mL of sodium silicate solution an pour it in one beaker. Pour 3 mL of ethyl alcohol in the other beaker. Be careful with both of these liquids and try not to let them touch your skin. Add the ethyl alcohol to the sodium silicate solution very slowly and then stir it with the stirring rod. After a solid is formed, put it in the palm of your hands and press on it. Try to form a sphere. You will have to occasionally wet down the sphere to keep the crumbles in place. Record your observations and try bouncing the polymer. To dispose of the polymer, put it in the trash, not the sink.

Data and Pictures:

This is the 2 small beakers with the ethyl alcohol (right) and sodium silicate solution (left). The sodium silicate solution is thicker and is a cloudy white. The ethyl alcohol is clear and is like water as far as consistency goes.

This is the beaker right as the polymer started forming. You can kind of see the polymer starting to form around the sides of the beaker and get lines in it as it solidifies. 

This is the polymer after about a minute of stirring. A polymer was formed instantly, but it took a while to get the crumbles to attach to the main clump of the polymer. Some of the polymer was left behind  and it was still very crumbly and it was very white.

This is the polymer after we had tried to press it into a ball for a while. You can see all the crumbles on the paper and our hands. It was drying out at this point and it was kind of rough and sandy. Little pieces broke off everywhere, making our polymer smaller.

This is after we added water to the polymer. It got very glossy, but it still would not form a ball. There were still a few crumbly pieces and they would not stick together easily. If we got the crumbles to stick, they would not mold into a sphere. The pieces of polymer were splotchy ranging from a cloudy clear to a bright white. 

Even though we did not get a sphere, other groups did. This is one of the ones that worked. It is the size of a large marble and is white but still has a few clear patches that are not visible in this picture. It is very smooth and rubbery. It feels sort of wet or at least moist. It was very bouncy and it held its shape. When I bounced the polymer, it came all the way back up to where I had dropped it from. 

Relation to the slime Polymer I did last post:
They were the same because:

• The silicon molecule was very close to the borax molecule in structure                       
• They both started to form instantly and started their formation at the sides of the beaker.
• They both left residue in the beaker. 
• Both of them are polyatomic.

They were different because:

• The slime did not bounce half as much as this polymer this polymer bounced up really fast and exactly where you wanted it too.

• Two liquids were used to make this polymer instead of and elastomer and a solid.
• This polymer held its shape pretty well and if it was molded too much, it crumbled but the slime was very moldable and squishy and it didn't dry out or crumble.
• In this polymer, the oxygen atoms are replaced by ethyl atoms instead of all the atoms just linking to each other.
• This polymer changed color and was not one solid color but the slime was one color and took on the white color and left behind the clear color. The clear was just water though, and most of the water was left behind in the slime polymer. No water was used in this polymer besides the water in the sodium silicate solution which was already mixed in.
• You could tell when the chemical reaction was taking place because a solid started to form.