  The multifaceted applications of polymers are often limited by their thermal
conductivity. Therefore, understanding the mechanisms of thermal transport in
polymers is of vital interest. Here, we leverage molecular layer deposition to
grow three types of hybrid metalcone (i.e., alucone, zincone, and tincone)
films and study their thermal and acoustic properties. The thermal conductivity
of the hybrid polymer films ranges from 0.43 to 1.14 W/mK. Using kinetic
theory, we trace the origin of thermal conductivity difference to sound speed
change, which is dictated by the structural disorder within the films. Changing
the disorder has negligible impacts on volumetric heat capacity and vibrational
lifetimes. Our findings provide means to improve the thermal conductivity of
organic, hybrid, and inorganic polymer films.
