The current experimental investigation presents a comparative evaluation of selected biodegradable polymer blends and their composites, focusing on their material properties. Two biopolymers, polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT), along with pineapple fibers (F), as bio-reinforcement were taken for the analysis, which was conducted in two stages: During first stage, PBAT was melt-blended with PLA in varying weight fractions (10, 20, 30, 40, and 50 wt%) to produce PLA/PBAT blend (B) and in second stage, PLA, PBAT, B 80/20 blend were reinforced with pineapple fiber (10, 20, and 30 wt%). The samples were fabricated using extrusion-injection molding. The samples were characterized for density, thermal degradation, crystallinity, and mechanical behaviour. Among the blends, the optimal B 80/20 combination exhibited tensile strength, flexural strength, and elongation at break of 47.9±2.4, 88.2±5.4 MPa, and 330.6±10.47%, respectively. Results indicate that the PLA-based composites (PF) exhibit significantly better density, tensile strength, and flexural strength as compared to neat polymers, blends, blend-based composites (BF), and PBAT-based composites (TF). Among the PF composites, the PF 70/30 composite demonstrated superior performance, with maximum tensile and flexural strength values of 73.9±1.3 and 107.1±4.3 MPa, respectively.

Bacterial cellulose (BC) is an eco-friendly biopolymer with outstanding structural and functional properties, offering promising applications in sustainable packaging and bio-based materials. In this study, we demonstrate the feasibility of producing BC via spontaneous fermentation, using grape pomace supplemented with sucrose as the sole carbon source, nutrient substrate, and microbial inoculum, without the addition of commercial strains or nitrogen supplements. Fermentation was conducted under static conditions, yielding biofilms with stable structural characteristics and BC production of up to 14.1 g/L, thereby confirming the efficiency of this low-cost, residue-based process. The films obtained exhibited well-organized polymeric networks, with thermal stability in the range of T_g ≈ 159–266 °C and mechanical resistance comparable to or higher than conventional biopolymers. Characterization confirmed reproducible chemical profiles, thermal stability, and measurable variation in mechanical performance, with a tensile strength ranging from 0.0001 to 105 MPa and an elongation at break of 15±5%. The process highlights a resource-efficient and sustainable pathway, adaptable to rural contexts and aligned with circular economic principles. While minor variations among replicates reflected the intrinsic variability of biological systems, mean values and standard deviations demonstrated reproducible physicochemical and mechanical properties. These findings demonstrate that BC derived from agro-industrial residues can be produced under simple, low-input conditions, opening opportunities for scalable valorization in functional and sustainable materials.

Maleic anhydride (MA) is widely used to modify plastics and as a compatibilizer in recycling. This study examines the effect of varying MA concentrations on blends of polyoxymethylene (POM) and recycled polyvinyl butyral (rPVB) from automotive windshields. Morphological analysis showed that MA contents between 0.25 and 0.75 wt% led to smaller, more closely dispersed rPVB particles, indicating enhanced phase miscibility. Rheological and thermal analyses revealed up to a 47% increase in melt flow index at lower MA concentrations, and improved interfacial interactions and crystallinity at higher levels. The tensile modulus dropped by 10% at 0.25 wt% MA but increased with further additions; tensile strength and Shore D hardness remained unaffected. Impact strength improved by up to 65% with MA addition, mainly due to increased ductility and a morphology characterized by larger rPVB domains and shorter interparticle distances at low MA contents. The coefficient of friction decreased with rPVB but increased with MA, along with higher volume loss. Microscopic wear analysis confirmed that rPVB dispersion, influenced by MA, was key to transfer film formation and surface lubrication. Thus, MA optimization enables tailored mechanical and tribological properties in POM/rPVB blends.

Waste rubber management through developing blends of thermoplastics with ground tire rubber (GTR) has gained significant attention for creating sustainable, high-performance materials with enhanced properties. In this work, we developed customized graphene/polymer nanocomposites applying GTR, ethylene-vinyl acetate copolymer (EVA), and graphene nanoplatelets (GNPs), taking carbon black (CB) as the reference additive. A wide range of electrical conductivity from 10^–12 S/cm (dielectric) to 10^–5 S/cm (semiconductor) was obtained for optimized composites containing GNPs and CB, respectively. Thermal, mechanical, and flame-retardant properties looked promising for additive manufacturing, while electrical conductivity was tailored for soft electronics. In view of processability, mechanical strength, and elasticity, GNPs-incorporated EVA/GTR composites showed an edge over their CB-aided counterparts. For example, tensile strength and elongation at break of EVA/GTR blends reinforced with 20 phr GNPs were 4.8 MPa and 681%, respectively, compared to 4.0 MPa and 651% for the composite comprising an identical amount of CB. Interestingly, combining GNPs and CB enhanced the thermal stability and flame retardancy of EVA/GTR compared to only GNPs or CB. These results were promising from both sustainability and advanced functional materials perspectives.

The growing need for sustainable materials has stimulated research into eco-friendly composites, with biochar emerging as an important reinforcement in polymer matrices. Biochar is a carbon-rich material produced by pyrolyzing organic biomass, offering various benefits over traditional fillers, including sustainability, waste reduction, and carbon sequestration. This study explores the effects of bamboo biochar as a hybrid reinforcement on the properties of polylactic acid (PLA)-rice husk composites. The present hybrid composites are prepared by varying the bamboo biochar from 5–25% and have better mechanical properties than PLA and its composite reinforced with a rice husk filler. The tensile, flexural, and compressive strengths of 51.5, 166.0, and 77.5 MPa are measured for the biochar percentage of 10%, representing increases of 73.1, 150.0, and 58.2% compared to PLA, and 158.2, 98.6, and 31% compared to the PLA composite with rice husk. Higher tensile and flexural moduli of 1.46 and 7.34 GPa are observed for 10 and 15%, respectively. However, the impact strength decreases with higher biochar content due to increased rigidity. The material’s hardness increases at higher biochar content due to enhanced stiffness. Thermal transition and degradation points rise due to increased crystallinity from the biochar reinforcement’s nucleation effect. Additionally, the hydrophobic biochar reinforcement reduces water absorption of PLA composite from 3.2 to 1.6%.