Understanding the nature of glass transition, as well
as the precise
estimation of the glass transition temperature for polymeric materials,
remains open questions in both experimental and theoretical polymer
sciences. We propose a data-driven approach, which utilizes the high-resolution
details accessible through the molecular dynamics simulation and considers
the structural information on individual chains. It clearly identifies
the glass transition temperature of polymer melts of weakly semiflexible
chains. By combining principal component analysis and clustering,
we identify the glass transition temperature in the asymptotic limit
even from relatively short time trajectories, which just reach into
the Rouse-like monomer displacement regime. We demonstrate that fluctuations
captured by the principal component analysis reflect the change in
a chain’s behavior: from conformational rearrangement above
to small fluctuations below the glass transition temperature. Our
approach is straightforward to apply and should be applicable to other
polymeric glass-forming liquids.