Our polymer idea is eco-friendly and child-safe polymer clay. We would want all the properties normal polymer clay has such as the ability to hold its shape, its flexibility, softness, and that it dries hard. Our plan was to take a basic dough recipe (cornstarch + water) but to alter it to fit the properties of polymer clay.
We first started out the basic clay recipe, but it was too hard and not moldable at all. We then decided to add some guar gum to give it an elasticity that is closer to polymer clay. We tried two prototypes one with 2 parts cornstarch 1 part guar gum and one with 1 part cornstarch 2 parts guar gum. Both were either too soft or too hard.
The process we went through was testing and revising until we got the perfect consistency.
Here is the final recipe:
6 tbs cornstarch
2 tbs guar gum
40 ml water
- Take cornstarch, guar gum and water. Mix
- Heat using microwave (light heat) for 30 seconds with 10 minute intervals
- Knead until clay
When you mix cornstarch, guar gum and water together it forms a frosting like consistency and the water gives the cornstarch and guar gum some room to move around so they can start forming long polymer chains. When you microwave the substance, the cornstarch/guar gum polymers will grab onto each other making them stick together- thus forming the clay.
A problem we encountered is that it cracks when it dries. We used different prototypes and compared them when they dried. The last prototype cracked the least and meets all our expectations.
Here is a picture of our second clay prototype when put through the ‘crack test’ (mentioned above)
Here are pictures of our final prototype
Justice, Lisa. “Corny chemistry.” Corny chemistry – Explorit Science Center. 23 May 2019 <http://www.explorit.org/news/corny-chemistry>.