Role of Phase Compatibility in Gas Barrier Improvement of Biodegradable Polymer Blends for Food Packaging Application

Properties and environmental sustainability of fungal chitin nanofibril reinforced cellulose acetate films and nanofiber mats by solution blow spinning

Materials from biological origin composed by renewable carbon facilitate the transition from linear carbon-intensive economy to a sustainable circular economy. Accordingly, we use solution blow spinning to develop fully biobased cellulose acetate films and nanofiber mats reinforced with fungal chitin nanofibrils (ChNFs), an emerging bio-colloid with lower carbon footprint compared to crustacean-derived nanochitin. This study incorporates fungal ChNFs into spinning processes for the first time. ChNF addition reduces film surface roughness, modifies film water affinity, and tailors the nanofiber diameter of the mats. The covalently bonded β-D-glucans of ChNFs act as a binder to improve the interfacial properties and consequently load transference to enhance the mechanical properties. Accordingly, the Young's modulus of the films increases from 200 ± 18 MPa to 359 ± 99 MPa with 1.5 wt% ChNFs, while the elongation at break increases by ~45 %. Life cycle assessment (LCA) is applied to quantify the environmental impacts of solution blow spinning for the first time, providing global warming potential values of 69.7-347.4 kg·CO2-equiv.·kg-1. Additionally, this work highlights the suitability of ChNFs as reinforcing fillers during spinning and proves the reinforcing effect of mushroom-derived chitin in bio-based films, opening alternatives for sustainable materials development beyond nanocelluloses in the near future.

Silane treated starch dispersed PBAT/PHBV-based composites: Improved barrier performance for single-use plastic alternatives

The objective of this study is to include 5 wt% silane-treated starch (S-t-Starch) into biodegradable flexible poly(butylene adipate-co-terephthalate) (PBAT)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) blend matrix, which can facilitate superior barrier and balanced mechanical properties. With the intension of improving compatibilization between matrix and filler, starch (biological macromolecule) was efficiently treated with 15 wt% of 3-glycidoxypropyl trimethoxy silane (GPTMS), a coupling agent. Various analyses such as barrier, mechanical, thermal, surface morphology and rheological were performed using cast extruded PBAT/PHBV-based composite films. Comprehensive characterizations suggested that cast extruded PBAT/PHBV with 5 wt% S-t-Starch composites exhibited 91 and 82 % improvement in oxygen and water vapor barrier, respectively, compared to PBAT film. The increment in % crystallinity (as supported by DSC analysis) of PBAT/PHBV/5%S-t-Starch composite due to the silane component was one of the reasons for barrier improvement. The other reason was the improved interfacial adhesion between matrix and S-t-Starch particles (as supported by SEM analysis), which restricted the mobility of the polymer chains. The elongation at break (%EB) of the cast extruded PBAT/PHBV/5%Starch film was slightly improved from 536 to 542 % after silane treatment. Hence, the developed polymer composite in this research work can contribute to flexible packaging applications that require improved barrier properties.