Round 4: Tossup 5

Characteristic ratios can be compiled for these molecules using the rotational isomeric state model. Symmetric “Maltese cross” patterns can be observed under polarized light when these molecules form semicrystalline spherulites (-5[1])(“sfir-ROO-lites”). Solutions of these molecules are considered ideal when the Mark–Houwink exponent equals one half (10[1])and the theta condition is reached. The interaction parameter chi (“kai”) is used to (10[1])calculate free energies (-5[1])of mixing for solutions of these molecules in the Flory–Huggins model. Atactic examples of these molecules usually have lowered glass-transition temperatures. Epoxy resins are “cured” into the thermoset type of these molecules, which are alternatively formed by step-growth (10[1])or chain-growth (10[1])methods. For 10 points, name these molecules made of repeating monomers. ■END■ (10[1])

Back to tossups

Buzzes

Summary