How is solubility affected by polymer chain structure?
The general principle is that "like dissolves like".
Thus, polar molecules like poly(acrylic acid), poly(acrylamide), and poly(vinyl alcohol) are soluble in water.
Nonpolar polymers such as polystyrene, poly(methyl methacrylate), poly(vinyl chloride), and poly(isobutylene) are soluble in nonpolar solvents.
Long chains can be densely entangled. This makes it difficult for solvent molecules to penetrate. So longer chains dissolve more slowly than short ones.
As crosslinking increases, solubility decreases. A high degree of crosslinking prevents polymer chains from escaping into solution.