Effect of polycyclosilane microstructure on thermal properties

Thermal characterization of polysilanes has focused on the influence of organic side chains, whereas little is understood about the influence of silane backbone microstructure on thermal stability, phase properties, and pyrolysis. To address this knowledge gap, we prepared three distinct polycyclosilanes: linear polymers synthesized from the cyclosilane building blocks 1,4Si(6) and 1,3Si(6), as well as a cyclic polymer of 1,3Si(6). Thermal properties across the temperature range 25 to 600 degrees C were investigated using differential scanning calromietry (DSC) and thermogravimetric analysis (TGA). We found differences between linear and cyclic materials, including a phase transition unique to the cyclic polymer and lower rates of mass loss during pyrolysis. Density functional theory (DFT) calculations provided insight into microstructure-dependent pyrolysis.

Automated summary

Thermal characterization of polysilanes has mainly focused on the influence of organic side chains, but this study demonstrates the importance of considering the microstructure of the silane backbone on properties such as thermal stability and pyrolysis behavior. The research showed distinct differences between linear and cyclic polysilanes, with cyclic polymers exhibiting unique phase transitions and lower rates of mass loss during pyrolysis. Density functional theory calculations provided valuable insights into the microstructure-dependent pyrolysis behavior of polysilanes.