Structural, Mechanical, and Environmental Assessment of a Poly(butylene adipate-co-terephthalate) (PBAT)-Inulin Composite Material

TL;DR

This paper studies a biodegradable composite material made of PBAT and inulin, evaluating its mechanical and environmental properties to find optimal formulations and reduce environmental impact.

Contribution

The study introduces a PBAT-inulin composite and uses a DoE approach to optimize mechanical properties and assess environmental impacts through LCA.

Findings

Inulin content significantly affects strain at break, with an optimal range of 4.4−4.5%.

PBAT production contributes most to environmental impacts, while inulin affects marine eutrophication and land occupation.

Using biobased PBAT and renewable electricity could reduce environmental burdens.

Abstract

The growing interest in mitigating the effects associated
with
the extensive production and consumption of fossil-based plastics
has led to increasing efforts in the development of biobased and biodegradable
materials. In this setting, poly­(butylene adipate-co-terephthalate) (PBAT) has emerged as a viable biodegradable alternative
to traditional polyesters. In this study, the manufacture of a PBAT-inulin
composite film is investigated to assess its structural, mechanical,
and environmental properties. A design of experiments (DoE) approach
was applied to limit the number of experiments and find potential
multivariate correlations (p-value <0.005) between
composite formulation, e.g., inulin content, and mechanical properties.
Results show that the inulin percentage has the highest influence
on the strain at break, which is found to decrease as the percentage
of inulin increases; as such, an ideal amount of inulin is found to
be equal to 4.4−4.5% of the composite. From an environmental
standpoint, results of a cradle-to-gate life cycle assessment (LCA)
(1 kg of composite as the functional unit) show that PBAT production
is the highest overall contributor to the impacts of the composite
(68% average across categories), whereas inulin presents the highest
contribution in the marine eutrophication (71%) and land-occupation
(44%) categories. Among the processing steps, composite extrusion
reports the highest average impacts at 14%. Also, a sensitivity analysis
suggests that adopting biobased PBAT and increasing the percentage
of renewable electricity consumed could reduce the cumulative environmental
burdens. Overall, this integrated approach can provide valuable information
for further optimization of both mechanical performance and environmental
sustainability, in line with the principles of Green Chemistry and
Green Engineering.

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