Methods of increasing thermal conductivity of a bulk polymer are provided. The methods include contacting a bulk polyelectrolyte polymer comprising an ionizable repeating pendant group with an aqueous liquid having a pH that ionizes the pendant group and isotropically extend the polyelectrolyte polymer to an extended non-globular chain conformation. The polyelectrolyte polymer so treated thus exhibits a thermal conductivity of greater than or equal to about 0.6 W/m·K and optionally greater than or equal to about 1 W/m·K. In other aspects, the present disclosure provides a high thermal conductivity material comprising a bulk polyelectrolyte polymer bearing a repeating charged group and having an extended non-globular chain conformation and that exhibits a thermal conductivity of greater than or equal to about 0.6 W/m·K and optionally greater than or equal to about 1 W/m·K. The high thermal conductivity material may be used in electronic devices, including as housings/encapsulation and thermal interfaces.