During the condensation polymerization of a specific polyester, which of the following changes in reaction conditions is most likely to enhance both the polymer's chain length and the formation of methanol as a byproduct?

Increasing the temperature while simultaneously removing the methanol that is released will push the equilibrium toward longer chains and more methanol. The higher temperature speeds up ester exchange and chain growth, and the vacuum or continuous methanol removal drives the reaction forward by Le Chatelier’s principle. As the methanol is pulled out, more ester bonds form, extending the polymer chain. For example, in the condensation of dimethyl terephthalate with ethylene glycol, raising the temperature to 180 °C and evacuating the methanol keeps the reaction moving toward high‑molecular‑weight PET. This dual change therefore lengthens the polymer and increases methanol production.