The objective of the present work was to investigate the effect of CMC biopolymer on the physicochemical, mechanical, thermal, barrier, and biodegradation properties of PVA-based films. The polymeric films were developed using solution casting method, incorporating CMC at concentrations ranging from 0.5 to 1.5%. With the addition of CMC, the tensile strength (TS) of the hybrid films was reduced from 1.40 +/- 0.02 MPa to 1.99 +/- 0.02 MPa. However, there was a significant improvement in the elongation at break (EAB) up to 49.29% compared to PVA film. The addition of CMC resulted in substantial improvements in water vapor permeability (WVP) and moisture retention capacity (MRC), showcasing a 38.73% improvement in WVP and a satisfactory MRC of 78.374% at 0.5% CMC concentration. The hybrid films also exhibit enhanced light absorbance at UV wavelength with opacity ranging from 0.301 to 1.413. TGA analysis showed a notable enhancement in the decomposition temperature of the hybrid PVA/CMC films, resulting in reduced mass loss compared to the PVA film. FTIR spectra confirmed that blending CMC with PVA led to the formation of strong hydrogen bonds within the polymer blend, significantly affecting the intermolecular forces inside the cellulose matrix. Moreover, with the addition of CMC, the degradation rate of the PVA/CMC film was increased approximately to 40% on the 30th day of soil burial. The films also exhibit effective microbial degradation against Pseudomonas putida and Bacillus subtilis bacteria strains as compared to commercial plastics. Overall, the obtained results validate the use of CMC biopolymer for blending of single polymer system as well as scaling down the extensive use of petroleum-based polymers in the field of packaging.

In the effort to mitigate environmental pollution there is a growing global demand for sustainable materials in place of existing synthetic one. In this research work, stacked hybrid laminate composite were produced by combining alkali treated kenaf and bamboo natural fiber mats as reinforcement with a biopolymer polylactic acid as matrix through compression moulding technique. The current work intends to study the outcome of surface modification of natural fibers which modifies their performance characteristics. Here the overall characteristics: mechanical, tribological, thermal and physical properties were investigated for the fabricated sample and the assessments were made between the alkali treated and untreated fiber composites. The alkali treated samples exhibited an enhanced tensile strength of 44.83 %, flexural strength of 108.13 %, compressive strength of 86.21 % and peak degradation temperature compared to the untreated samples. In addition, the tribological characteristics of the treated hybrid composites were studied. The inherent hydrophilic characteristics of natural fiber which leads to water absorption is resisted by the chemical treatment and it is also confirmed by the Fourier Transform Infrared (FTIR) analysis.Morphological analysis of the fractured and worn composites was also conducted to examine the microstructural changes and interface bonding within the developed composites. The biodegradability of the developed composites under soil burial test showed that the untreated composites exhibited higher weight loss percentage compared to the treated samples. The experimental results reveal that the alkali chemical treatment significantly enhances the suitability and compatibility of kenaf and bamboo natural fibers in polymer composites for sustainable construction products like roofing sheets and door panels in rural terrain regions.

Hydroxypropyl methylcellulose (HPMC) incorporated bio-composite films (unplasticized and plasticized) were prepared from pregelatinized maize starch/polyvinyl alcohol (PMS/PVA) blends by solution casting method. 10% boric acid (BA) was used as crosslinker. The physico-mechanical properties (tensile strength (TS), elongation at break (%EB), water solubility and moisture uptake) of the bio-composite films were studied. The thermo-chemical stability of the biofilms was studied by FT-IR, TGA and DSC analysis. TS, %EB, water solubility and moisture absorbency of 10% HPMC containing unplasticized films were found 38.1 MPa, 8.5%, 61% and 32.3%, respectively, however, the films were hard and brittle. On the contrary, TS, %EB, water solubility and moisture absorbency of 10% HPMC plasticized films were found 19.2 MPa, 28.5%, 62.2% and 57.3%. The biofilms exhibited relatively low water solubility and moisture uptake compared to higher HPMC containing composite. The thermo-chemical analysis revealed that the HPMC incorporated plasticized film was more thermally stable compared to pure PMS, PVA, HPMC and other bio composite films due to strong hydrogen bonding interaction with BA. The biodegradability of HPMC incorporated plasticized films was confirmed by soil burial test (anaerobic condition, RH 98%, 3 months). Therefore, the plasticized biofilm would be considered an alternative approach for biocompatible packaging material.

The production of tomatoes faces significant challenges, including the high amount of waste generated during the harvest stage and copper-contaminated soil due to pesticide use. To address these issues and to promote a more sustainable agriculture, innovative biodegradable green composites for contextual controlled soil fertilization and Cu removal were produced by 3D-printing technology. These composites were made by incorporating NPK fertilizer flour and tomato plant waste particles (SLP) into three different biodegradable polymeric matrices: polylactic acid (PLA); a commercial blend of biodegradable co-polyesters (Mater-Bi (R), MB) and their blend (MB/PLA, 50:50). Rheological characterization suggested the potential processability of all of the composites by FDM. Morphological analysis of printed samples confirmed the good dispersion of both filler and fertilizer, which also acted as reinforcement for MB and MB/PLA composites. SLP and NPK moduli were evaluated by powder nanoindentation and, for almost composites, the theoretical Halpin-Tsai model satisfactorily fitted the actual tensile moduli. The decrease in NPK fertilizer release rate and the increase in Cu(II) removal efficiency were achieved using whole 3D-printed composites. By selecting the appropriate matrix and incorporating SLP particles, it was possible to tune the NPK release rate and achieve copper absorption efficiency. Notably, MB samples containing SLP particles displayed the fastest release and the highest Cu(II) removal efficiency.

Among the sectors influencing the environment, the building sector is known to be very energy consuming and to use large granular materials. Face to these problems, the development of materials based on renewable and biodegradable resources represents amajor scientific challenge to produce high-performance materials and materials that can be used as an alternative to synthetic materials. Several materials have been studied and proposed, in particular for the thermal insulation of buildings [1]. However, these materials based on vegetable aggregates remain, in most cases cement or lime-based [2], which are energy consumers and emit carbon dioxide [3, 4]. This work aims to propose a bio-composite with both vegetable aggregates and binders with thermal performances that are competitive with materials based on mineral binders. Vegetable glues were extracted using wheat straw fines that cannot be used as aggregates. The straw fines were soaked in a solution containing 6% NaOH at 90 degrees C for 2 h. Then, the extracted liquid was concentrated by adding sunflower pith powder and/or gelatin. The bio-binder was mixed with the straw aggregates to prepare biocomposite samples using the protocol developed in the PEPITE research program funded by the Region Centre. Experimental results in thermal conductivity allowed us to examine the influence of each bio-binder and compare the performance of straw aggregate-based bio-composites developed [5, 6].