TEMPO-oxidized cellulose nanofibrils increase tensile strength by 80% and enhance barrier and biodegradation performance in PLA/PBAT nanocomposites: a systematic meta-analysis

Background Biodegradable poly (lactic acid)/poly (butylene adipate-co-terephthalate) (PLA/PBAT) blends suffer from poor interfacial adhesion and suboptimal mechanical performance, limiting their use in sustainable packaging. Methods A PRISMA-compliant systematic meta-analysis of 34 peer-reviewed publications (2018–2025) was conducted. Inclusion criteria required studies reporting tensile, thermal, or barrier data on PLA/PBAT blends with nanocellulose ≥2 wt%. Heterogeneity was assessed using Cochran’s Q and I 2 statistics; sensitivity analysis confirmed robustness. Data were normalized to a 70/30 PLA/PBAT reference composition using a validated linear mixing-rule protocol (R 2 = 0.91), acknowledging that this approach may introduce systematic bias for properties exhibiting nonlinear composition dependence, particularly barrier properties. Results Surface-modified TEMPO-oxidized CNFs at 5 wt% achieved the most significant improvements: tensile strength increased 80% (28.4 → 51.2 MPa), Young’s modulus increased 158% (1.2 → 3.1 GPa), thermal degradation onset temperature improved by 35 °C (295 → 330 °C), and water vapor permeability decreased 57% (15.2 → 6.5 g mm/m 2 ·day at 100 μm reference thickness). Crystallinity increased from 32% to 55%, and activation energy for thermal degradation rose from 155.8 to 205.3 kJ/mol. Nanocellulose incorporation accelerated biodegradation under industrial composting conditions (ISO 14855-1, 58 °C, 60%–65% RH), reducing half-life from 12.0 to 7.9 weeks and increasing degradation (weight loss) to 86% at 12 weeks (CO 2 -based mineralization efficiency: 81%). The tortuosity factor increased from 1.2 to 2.4, consistent with Nielsen’s tortuous path model. Conclusion Surface-modified nanocellulose enables high-performance, fully biodegradable composites suitable for sustainable packaging, with biodegradation rates meeting the ISO 14855-1 threshold of EN 13432. Full certification additionally requires disintegration and ecotoxicity data not available in the present meta-analysis corpus. Performance is comparable to, or exceeds, that of synthetic nanoreinforcements (CNTs, organoclays) in independent studies—though direct comparison under identical conditions would be needed to establish definitive superiority—while offering full biodegradability.