Predicting the viscosity (η) of polymer nanocomposites
(PNCs)
is of critical importance as it governs a dominant role in PNCs’
processing and application. Machine-learning (ML) algorithms, enabled
by pre-existing experimental and computational data, have emerged
as robust tools for the prediction of quantitative relationships between
feature parameters and various physical properties of materials. In
this work, we employed nonequilibrium molecular dynamics (NEMD) simulation
with ML models to systematically investigate the η of PNCs over
a wide range of nanoparticle (NP) loadings (φ), shear rates
(γ̇), and temperatures (T). With the
increase in γ̇, shear thinning takes place as the value
of η decreases on the orders of magnitude. In addition, the
φ dependence and T dependence reduce to the
extent that it is not visible at high γ̇. The value of
η for PNCs is proportional to φ and inversely proportional
to T below the intermediate γ̇. Using
the obtained NEMD results, four machine-learning models were trained
to provide effective predictions for the η. The extreme gradient
boosting (XGBoost) model yields the best accuracy in η prediction
under complex conditions and is further used to evaluate feature importance.
This quantitative structure–property relationship (QSPR) model
used physical views to investigate the effect of process parameters,
such as T, φ, and γ̇, on the η
of PNCs and paves the path for theoretically proposing reasonable
parameters for successful processing.