I just read the article on the clay and PVA mixture to see what I could learn from it, and though it is mostly over my head, I learned enough from it.
http://image.sciencenet.cn/olddata/kexue.com.cn/blog/admin//images/upfiles/20071217222011250911.pdf
It seems that all of the crosslinks in our formula would have to be hydrogen links.
In this website, it gives me more clues as it pertains to that:
http://courses.chem.psu.edu/chem112/materials/polymers.html
For example:
In theses paragraphs, it describes what we want:
"The strongest non-covalent forces are
hydrogen bonds, which involve a positively charged hydrogen interacting with an electronegative element. Only hydrogen that is bonded to nitrogen, oxygen, or fluorine can do it, e.g. in OH...O, OH...N, NH...O, OH...F, etc. interactions. Take, for example, the nylon polymer. There are NH groups that can make hydrogen bonds to the C=O groups of another chain. Each of these hydrogen bonds is worth only about 15-20 kJ/mole, compared to 300-400 kJ/mole for a covalent bond. Nevertheless, lots of interchain hydrogen bonds add up, making the nylon polymer rather stiff and giving it a Tg of 57oC."
"
Viscoelasticity. There is a property that distinguishes polymers from all other types of materials. This property is termed viscoelasticity, and is most easily appreciated by considering the behavior of Silly Putty (polydimethylsiloxane), or the slime (polyvinylalcohol, PVA) we made in class. The silicone polymer contains a -Si-O-Si-O- backbone that terminates in Si-OH groups, and these chain ends are crosslinked by making hydrogen bonds with boric acid, B(OH)3. The linear PVA chains were crosslinked the same way. Unlike covalent bonds, hydrogen bonds can form, break up, and then form again many times in the liquid state. Without these weak crosslinks, Silly Putty could only be a very viscous liquid - it wouldn't bounce. When Silly Putty is thrown at a wall it bounces back, a behavior characteristic of an elastic solid. However, under (slower) tensile or compressive stress, like pulling or squeezing, it deforms like a viscous liquid. How can a material be
both an elastic solid and a viscous liquid? The key is the timescale of the deformation. Under application of rapid stress, like bouncing it against a wall, the hydrogen bonds in the polymer don't have time to break and re-form; therefore the deformation is elastic. Slow pulling results in plastic deformation, because there is sufficient time to break and re-form these non-covalent bonds. Recall that the slime we made had the same properties - it deformed like a liquid under the force of gravity, but only slowly - it felt solid enough if somebody threw a hunk of it at you. The phenomenon of viscoelasticity is therefore time-dependent."
So as we see, we can determine which plastic we hould use based on it's overall charge. While the chemistry will be a little difficult with reactivity and other such things to consider, we at least have limitations that will make the search easier. For example, this line "There are NH groups that can make hydrogen bonds to the C=O groups of another chain," tells us that we want a plastic that dissolves in acetone or water that contains NH groups, as graphene contains C=O groups.
