|MadSci Network: Chemistry|
Dear Carea, PVA (polyvinyl alcohol) is a polymer that dissolves in water. As water dries, the PVA molecules begin to link together to form chains of different lengths. Certain surfactants and other chemicals can act as "crosslinking agents" that will cause the chains to link together to form a gel-like structure ("slime"). Traditionally, the most common crosslinker is Borax (sodium borate). Paints contain many chemicals and surfactants which could crosslink the PVA chains as readily as borate does.
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