A reactive synergist (BAAEP) was designed for PP, paired with IFR(APP/CFA) for two-phase flame retardancy. It catalyzed charring, scavenged radicals, and synergized with IFR's intumescent effect for efficient flame retardancy and smoke suppression.

While biodegradable plastics alleviate plastic pollution, their degradation-derived biodegradable microplastics (BMPs) pose new ecological risks, necessitating efficient quantification methods. This study explores a label-free approach by leveraging the intrinsic fluorescence of common biodegradable polyesters (PLA, PHB, PBS, PBAT, PCL). We find that biodegradable microplastics exhibit two types of characteristic fluorescence emission: one originating from molecular functional groups and the other originating from the chromophore formed by the aggregation of conjugated groups. Using PBAT as a model, we confirm that fluorescence intensity depends on the BMPs’ size and shape. Under 380 nm excitation, concentration-dependent signals are observed at 436 nm (indirectly from PBAT-enhanced water Raman scattering) and 465 nm (directly from PBAT intrinsic fluorescence), leading to successful linear models between BMPs’ mass concentration and fluorescence intensity over 100–500 mg/L, with correlation coefficients (R²) of 0.877 and 0.963, respectively. Compared with the fluorescence labeling method, the intrinsic fluorescence approach achieves comparable R² while exhibiting lower signal intensity (~10³). Nevertheless, its operational simplicity offers a distinct advantage for the rapid quantification of pre-isolated and purified microplastics.

Lignin is a promising bio-based filler for poly(butylene adipate-co-terephthalate) (PBAT), yet its true contribution to biodegradation remains unclear—most studies rely on weight loss alone, neglecting CO₂ mineralization and lignin’s antibacterial activity. Here, lignin/PBAT composites with 1 wt% (LP-1) and 3 wt% (LP-2) lignin are assessed under composting conditions using both weight loss and mineralization rate. Lignin exhibits a dual role: it promotes hydrolytic weight loss (18.3% and 28.6% for LP-1 and LP-2 at 40 days), but significantly inhibits ultimate mineralization (one-year mineralization: 65.71% for pure PBAT vs. 48.74% and 29.53% for LP-1 and LP-2). A negative initial mineralization rate suggests transient antibacterial activity from released phenolic compounds. Lignin increases crystallization temperature (48.4 → 92.6 °C) and T_g (−28.5 → 49.1 °C), with 1% loading largely preserving mechanical properties. These findings demonstrate that weight loss alone is insufficient to assess degradation; mineralization must be included. Appropriate lignin loading enables balanced performance and degradation controllability, offering new insights into lifecycle assessment of green composites.