Hi, Im learning about polymers. I did a lab to make slime where I mixed PVA glue & water. I then added borax to some water in another container, and the poured off the water from the wet borax. I then added the borax to the glue/water solution. I have to make a procedure that will produce a more runny slime, so I figured that I should add less water TO THE BORAX, because a condensation polymer is happening( I think????) and they become stronger with more intermolecular bonds (formed form the H atoms in the water)...Is my thinking right?
This is a great opportunity for you to experiment. The slime I have seen made usually becomes harder with more kneading; therefore, I would try more water as a separate experiment.
WHAT DO YOU MEAN MORE KNEADING? and that would cause it to become harder right and not as runny? so if I kneaded less it would be runnier? if so why is this?
http://chemistry.about.com/cs/howtos/ht/slime.htm
Your thinking is partly correct! The formation of slime in this experiment is not due to a condensation polymerization, but rather a cross-linking reaction between polyvinyl alcohol (PVA) and borate ions from the borax. I can explain the process and help you understand how to adjust the procedure to make a more runny slime.
When PVA glue is mixed with water, the PVA chains can freely move around and flow, creating a liquid-like consistency. However, when borax is added to the solution, the borate ions form cross-links with the PVA chains. These cross-links link the PVA chains together, creating a network structure and transforming the solution into a gel or slime.
To make a more runny slime, you correctly identified that reducing the amount of water in the borax solution can be a good approach. This is because adding more water to the borax solution would potentially increase the number of borate ions available to cross-link the PVA chains, resulting in a stronger and thicker slime.
Here's a step-by-step procedure to produce a more runny slime:
1. Mix PVA glue and water in a container, maintaining a certain ratio (e.g., 1:1 or 2:1 glue to water).
2. In another container, dissolve borax in water, also maintaining a ratio (e.g., 1 tablespoon of borax dissolved in 250 mL of water).
3. Pour off excess water from the borax solution, leaving behind a concentrated borax solution.
4. Slowly add a small amount of the concentrated borax solution to the glue/water mixture while stirring continuously.
5. Observe the consistency of the slime as you add the borax solution. If you want a more runny slime, add a smaller amount of the concentrated borax solution.
6. Continue adding the borax solution gradually until you achieve your desired slime consistency. Remember to stir continuously while adding the borax solution.
7. Once you reach the desired consistency, remove any excess liquid from the slime.
By adjusting the amount of water in the borax solution, you can control the strength of the cross-linking reaction and ultimately achieve a more runny slime.