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The canola oil industry generates significant waste as canola meal (CM) which has limited scope and applications. This study demonstrates the possibility of valorization of CM as a sustainable natural filler in a biodegradable polymer composite of Poly(lactic acid) (PLA). Generally, interfacial bonding between natural fibers and the polymer matrix in the composite is weak and non-uniform. One possible solution is to derivatize natural fibre to introduce interfacial bond strength and compatibility with the PLA polymer matrix. Here, CM was succinylated in a reactive extrusion process using succinic anhydride at 30 wt% to get 14% derivatization with 0.02 g of -COOH density per g of CM. The CM or succinylated CM at 5 and 15 wt% was co-extruded with amorphous PLA to get composite fibers. CM-PLA and succinylated CM-PLA biocomposites were foamed using a mild and green microcellular foaming process, with CO2 as an impregnating agent without any addition of organic solvents. The properties of the foams were analyzed using differential scanning calorimetry (DSC), Dynamic mechanical thermal analysis (DMTA), shrinkage, and imaging. The addition of CM or succinylated CM as a natural filler did not significantly change the glass transition temperature, melting point, percent crystallization, stiffness, and thermal stability of PLA foams. This suggests succinylation (modification) of CM is not a mandatory step for improving interphase compatibility with the amorphous PLA. The new PLA-CM foams can be a good alternative in the packaging industry replacing the existing petroleum-based polymer foams. Highlights: Valorization of CM as a sustainable natural filler in PLA biocomposite foams Modification of CM is not mandatory for interphase compatibility with the PLA PLA-CM foams have similar appearance and properties to control PLA foams New PLA-CM foams can be a good alternative in the packaging industry [ABSTRACT FROM AUTHOR]

The use of wheat middlings (WM) and rice husks (RH) as biofillers for mixing with poly(lactic acid) (PLA) matrix to produce new 3D-printable biocomposites was assessed. Filaments containing 10 and 20 wt.% agro-waste-derived biofillers were manufactured and, for the sake of comparison, filaments of neat PLA were also produced. The obtained filaments were characterized via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), showing potential for further application in additive manufacturing processing. Three-dimensionally printed specimens were thus produced and characterized via: DSC, also evaluating the specific heat capacity (CP) of specific 3D-printed specimens; dynamic mechanical analysis (DMA), also applied for determining the coefficient of linear thermal expansion (CLTE) measured on 3D-printed specimens in two different directions (X and Y); and tensile tests. The latter testing campaign was carried out along three printing directions (X, Y, and Z axes) to test the intrinsic biocomposite features (X-printed samples) as well as interbead and interlayer adhesion (Y- and Z-printed specimens, respectively). All samples demonstrated acceptable properties. The inclusion of a cost-free natural material leads to a strong reduction of the whole material cost. Implementing this new class of composite material to an additive manufacturing technique can significantly reduce the environmental impact of 3D-printed products. [ABSTRACT FROM AUTHOR]

The utilization of multifunctional composite materials presents significant advantages in terms of system efficiency, cost-effectiveness, and miniaturization, making them highly valuable for a wide range of industrial applications. One approach to harness the multifunctionality of carbon fiber reinforced polymer (CFRP) is to integrate it with a secondary material to form a hybrid composite. In our previous research, we explored the use of carbonaceous material derived from coconut shells as a sustainable alternative to inorganic fillers, aiming to enhance the out-of-plane mechanical performance of CFRP. In this study, our focus is to investigate the influence of carbonized coconut shell particles on the non-structural properties of CFRP, specifically electromagnetic interference (EMI) shielding, thermal stability, and water absorption resistance. The carbonized material was prepared by thermal processing at 400 °C. Varying proportions of carbonized material, ranging from 1% to 5% by weight, were thoroughly mixed with epoxy resin to form the matrix used for impregnating woven carbon fabric with a volume fraction of 29%. Through measurements of scattering parameters, we found that the hybrid composites with particle loadings up to 3% exhibited EMI shielding effectiveness suitable for industrial applications. Also, incorporating low concentrations of carbonized particle to CFRP enhances the thermal stability of hybrid CFRP composites. However, the inclusion of carbonized particle to CFRP has a complex effect on the glass transition temperature. Even so, the hybrid composite with 2% particle loading exhibits the highest glass transition temperature and lowest damping factor among the tested variations. Furthermore, when subjected to a 7-day water immersion test, hybrid composites with 3% or less amount of carbonized particle showed the least water absorption. The favorable outcome can be attributed to good interfacial bonding at the matrix/fiber interface. Conversely, at higher particle concentrations, aggregation of particles and formation of interfacial and internal pores was observed, ultimately resulting in deteriorated measured properties. The improved non-structural functionalities observed in these biocomposites suggest the potential for a more sustainable and cost-effective alternative to their inorganic-based counterparts. This advancement in multifunctional composites could pave the way for enhanced applications of biocomposites in various industries.

Poly(glycerol sebacate) (PGS) is a novel polymeric material intended for applications in tissue engineering (TE). This study involves synthesizing the PGS prepolymer (pPGS) and subsequent manufacturing of porous PGS-based scaffolds with an addition of hydroxyapatite (HAp) by means of thermally induced phase separation followed by thermal cross-linking and salt-leaching (TIPS-TCL-SL). The study aims to investigate the effect of the apatite filler content on properties and morphology of porous PGS/HAp scaffolds. The emphasis is put on the mechanical behavior of the material characterized by means of compression tests and dynamic thermal mechanical analysis (DMTA). In addition to the reference polymer scaffold, the composites with filler contents of 10, 20 and 30 wt% have been examined. Our research revealed that the HAp content does not affect the mechanical properties in a directly proportional manner. The 30 wt% addition of HAp resulted in frayed structure and decrease in the mechanical parameters in comparison to other tested specimens. On the other hand, an addition of 10% did not sufficiently boost the properties. Therefore, a 20% addition of HAp was concluded to have superior mechanical properties in comparison to other analyzed specimens. A similar relationship results from the DMTA studies. Moreover, the strain sweep and frequency sweep tests confirmed the stability of the mechanical parameters in various conditions, as well as the elastomeric nature of the materials. Finally, the material did not exhibit cytotoxicity against standard L929 fibroblasts and cells readily populated the scaffolds. [Display omitted] [ABSTRACT FROM AUTHOR]

Green nanocomposites based on polylactic acid (PLA) and Wood Flour (WF) with different loadings of graphene nanoparticles (GNPs) were produced by compressing molding process. The mechanical strength, dimensional stability, and viscoelastic behavior of nanocomposites were characterized by static mechanical analysis (flexural and tensile), water uptake, and dynamic mechanical analysis (DMA) tests. Results indicated that the incorporation of GNPS into the fabricated samples, significantly improved the mechanical properties of the composites. However, the water absorption and thickness swelling of the composites progressively decreased with increasing GNPs content. In general, the specimens filled with GNPs showed the highest values of storage and loss modulus compared with the other ones, due to the highest interaction taking place at the matrix–filler interface. Morphological images show that the GNPs were homogeneously and well-dispersed in the composites. Based on the findings obtained from the present study, it can be said that the optimum content of GNPs for the fabricated WPC samples is 2%. [ABSTRACT FROM AUTHOR]

In this paper, fracture toughness of banana fiber reinforced thermoplastic starch (BF_TPS) material was studied. Fiber weight percent (30, 40, and 50 wt.%) to starch polymer was fabricated using hot press at a pressure of 5 MPa of 160°C for 30 min. Experimental result shows that 40 wt.% BF_TPS biocomposite gave optimum tensile strength. Furthermore, nanoclay with varying weight percentage (1-5 wt.%) of dry cornstarch (CS) powder was added to enhance the property of the optimum 40 wt.% BF_TPS biocomposite, hence, forming hybrid clay/BF_TPS biocomposite. Tensile, impact, and fracture mechanics (Mode I fracture test) through Single End Notched Bending (SENB) Test were studied concurrently. Thermal properties and degradations were equally studied through Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analysis (TGA). Results show that tensile strength and impact resistance increased to the maximum of 65% and 15.6%, respectively, at 3 wt.% clay addition. Critical stress intensity factor (KIC) was approximately higher by 276% when compared to neat BF_TPS material. Strain energy release rates (GIC) values were minimal. Delamination and catastrophic failures occurred with less fiber crack propagation along the crack initiation notches. In TGA, less weight reduction was observed at 3 wt.% clay/BF_TPS material, while a positive shift occurred in DMA tan delta (Tan δ) Tg by 30°C. The micrography of the clay-enhanced biocomposites resulted in better bonding interaction between the polymer and fiber. [ABSTRACT FROM AUTHOR]

Thermomechanical pulp (TMP) fibres can serve as renewable, cost-efficient and lightweight reinforcement for thermoplastic polymers such as poly(lactic acid) (PLA). The reinforcing ability of TMP fibres can be reduced due to various factors, e.g., insufficient dispersion of the fibres in the matrix material, fibre shortening under processing and poor surface interaction between fibres and matrix. A two-level factorial design was created and PLA together with TMP fibres and an industrial and recyclable side stream were processed in a twin-screw microcompounder accordingly. From the obtained biocomposites, dogbone specimens were injection-moulded. These specimens were tensile tested, and the compounding parameters statistically evaluated. Additionally, the analysis included the melt flow index (MFI), a dynamic mechanical analysis (DMA), scanning electron microscopy (SEM) and three-dimensional X-ray micro tomography (X- μ CT). The assessment provided insight into the microstructure that could affect the mechanical performance of the biocomposites. The temperature turned out to be the major influence factor on tensile strength and elongation, while no significant difference was quantified for the tensile modulus. A temperature of 180 °C, screw speed of 50 rpm and compounding time of 1 min turned out to be the optimal settings. [ABSTRACT FROM AUTHOR]

The enhancement of the PLA thermomechanical properties is significant due to its suitability as a replacement for primary synthetic polymer use in diverse industrial production. The amphiphilic chitin was used as a compatibilizer in PLA/starch biocomposite. The properties of plasticised polylactic acid blended with starch, and amphiphilic chitin was studied for enhanced thermomechanical and viscoelastic properties. Chitin was modified using acetylated substitution reaction and blended with plasticised PLA/starch biocomposite. The biocomposite was prepared with combined compression and melt extrusion techniques. The biocomposite's thermomechanical, thermal, mechanical, and morphological properties were studied using dynamic mechanical analysis, TGA-DSC, tensile test, and scanning electron microscopy. The storage and loss modulus were significantly enhanced with increased amphiphilic chitin content. Similarly, the single peak of tan delta showed good miscibility of the polymeric blend. Additionally, the modulus increases with frequency change from 1 Hz to 10 Hz. The thermal stability of the biocomposite was observed to be lower than the neat PLA. The tensile properties of the biocomposite increased significantly more than the neat PLA, with P4S4C having the highest tensile strength and modulus of 87 MPa and 7600 MPa. The SEM images show good miscibility with no significant void in the fractured surface. The viscoelastic properties of PLA were enhanced considerably with plasticizer and amphiphilic chitin with improved biodegradability. The properties of the biocomposite can be adapted for various industrial applications. [ABSTRACT FROM AUTHOR]

This study deal with the development and investigation of a novel hybrid nano-shell plant fiber biocomposite. Nano-calcium carbonate CaCO3 ranging from 1 to 5 wt% and 20 wt% banana fiber-filled hybrid biocomposite were prepared using a hand lay-up process followed by applying load on a closed mold. Nano-CaCO3 of near-uniform size and shape was synthesized from Achatina Fulica through a mechanochemical technique. The effect loading fiber of uniform 30 mm size on the mechanical, physical, thermal properties of greenpoxy composite was investigated. The influence of nano-CaCO3 loading (1 to 5 wt%) on banana fiber-filled greenpoxy composite, dynamic mechanical properties, tensile, flexural, impact strength was further investigated. The result showed that the loading of banana fiber improved mechanical properties and negatively affected temperature dependence storage modulus, loss modulus, and tan δ. Better load carrying and stress distribution capacity of the fiber within the biocomposites can be attributed to the high strength and stiffness observed for these series. The poor thermal properties of banana fiber can be ascribed to a decrease in the temperature dependence properties. The loading of nano-CaCO3 improved most of the banana-filled greenpoxy biocomposite, and hybrid composite with 2 wt% nano-CaCO3 offered superior properties. Uniform dispersion, excellent matrix/nano-CaCO3/banana fiber adhesion provided a strong structure, resulting in improved mechanical and temperature-dependant properties. [ABSTRACT FROM AUTHOR]

• Novel low-melting point biopolyamide was synthesized via a copolymerization reaction. • Lignin modification was done through grafting of octadecyl isocyanate molecules. • Biocomposites with a high concentration of lignin were prepared. • Surface-modified lignin particles dispersed evenly in all biocomposites. • The mechanical properties of the biocomposite improved upon the addition of lignin. Blending polymers with a high concentration of bio-based fillers is one of the solutions that not only reduces a dependency on petroleum-based feedstocks but can also significantly decrease the carbon footprint. In the current study, n -octadecyl isocyanate (ODI) molecules were grafted on lignin particles to render them compatible with a novel copolyamide matrix, which was successfully synthesized through a copolymerization between petroleum- and bio-based monomers. Different concentrations of the surface-modified particles were melt-blended with a low-melting point copolyimide, and the properties of the developed biocomposites being thoroughly studied. The SEM imaging revealed that the surface-modified particles homogeneously dispersed into the polymer matrix for all loading levels without any clear evidence of particle agglomeration, phase separation, or voids formation, proposing excellent compatibility between the components that arose from a successful surface modification process. Furthermore, the mechanical properties of the biocomposites significantly improved. For instance, the yield stress and tensile modulus were enhanced by 50% and 200% at the biocomposite with 50 wt% filler content, without any considerable change in the tensile strain. The dynamic mechanical analysis, as well as the rheology measurements, further confirmed the uniform dispersion of the surface-modified particles and their compatibility with the copolymer matrix, within which the storage modulus considerably improved upon the increase of filler content. Overall, our findings strongly suggest that these newly developed biocomposites with a green content of up to 80% are attractive candidates for substituting petroleum-based plastics for the demanded applications. [ABSTRACT FROM AUTHOR]

In this study, novel acrylated epoxidized hemp oil bioresin was used in the manufacturing of jute fibre reinforced biocomposites. The 100% biocomposite laminates were characterised in terms of mechanical properties (tensile, flexural, Charpy impact and interlaminar shear), thermo-mechanical properties (glass transition temperature, storage modulus and crosslink density) and water absorption properties (saturation moisture level and diffusion coefficient). Comparisons with the equivalent synthetic vinylester resin based jute fibre reinforced biocomposite panels were performed. Scanning electron microscopic analysis confirmed panel samples containing acrylated epoxidized hemp oil to display improved fibre–matrix interfacial adhesion compared with the vinylester resin based samples. Furthermore in terms of mechanical properties acrylated epoxidized hemp oil based biocomposites compared favourably with those manufactured from vinylester resin synthetic resin. Dynamic mechanical analysis found acrylated epoxidized hemp oil based biocomposites to have lower glass transition temperature, storage modulus and crosslink density than vinylester resin based samples. Increasing acrylated epoxidized hemp oil content resulted in a marginal increase in saturation moisture content and diffusion coefficient. [ABSTRACT FROM PUBLISHER]

Kenaf-filled polylactic acid (PLA) biocomposites were prepared using dry blending, twin screw extrusion and compression molding. PLA was blended with raw and alkali treated kenaf, polyethylene glycol and ammonium polyphosphate (APP). Dynamic mechanical properties of biocomposites were investigated by dynamic mechanical analysis. Storage modulus of composites decreased, while magnitude of damping peaks increased with increase in APP content. TheTgof composites shifted to lower values with APP addition. Alkali treatment improved interfacial adhesion between PLA and kenaf. SEM analysis indicates good dispersion of APP in PLA matrix, however interfacial adhesion between PLA and matrix decreased with increasing APP content. [ABSTRACT FROM PUBLISHER]

Novel biocomposites made of an acrylated epoxidized hemp oil based bioresin reinforced with random hemp fiber mat were manufactured by the vacuum infusion technique. Mechanical properties (tensile, flexural, Charpy impact and interlaminar shear), dynamic mechanical properties (glass transition temperature, storage modulus and crosslink density) and moisture absorption properties (saturation moisture level and diffusion coefficient) were investigated and compared with samples manufactured under the same conditions but using a commercial synthetic vinylester resin as the polymeric matrix. Results showed that the 100% biocomposites mechanical performance is comparable to that of the hybrid composites made with the synthetic resin. Moisture absorption tests showed that acrylated epoxidized hemp oil based samples displayed both higher diffusion coefficient and saturation moisture content; however, fiber reinforcement was the dominant transfer mechanism. Vinyl ester based samples were found to have higher storage modulus, glass transition temperature and crosslink density than acrylated epoxidized hemp oil samples. [ABSTRACT FROM AUTHOR]

Biocomposites were prepared using epoxidized linseed oil and flax fibre reinforcements in different assemblies. Epoxidized linseed oil was cured by two different anhydrides to check how its thermomechanical properties can be influenced. As reinforcements, nonwoven mat, twill weave and quasi-unidirectional textile fabrics with two different yarn finenesses were used. Their reinforcing effect was determined using dynamic mechanical analysis in flexure. Dynamic mechanical analysis served to determine the glass transition temperature (Tg) also. Shape-memory properties were derived from quasi-unconstrained flexural tests performed near to the Tg of the epoxidized linseed oil and its biocomposites. Flax reinforcement reduced the Tg that was attributed to off-stoichiometry owing to chemical reaction between the hydroxyl groups of flax and anhydride hardener. The shape-memory parameters were moderate or low. They were affected by both textile content and type. [ABSTRACT FROM AUTHOR]

Novel epoxidized hemp oil-based biocomposites containing jute fibre reinforcement were produced at the Centre of Excellence in Engineered Fibre Composites (CEEFC) owing to the need to develop new types of biobased materials. Mechanical properties (tensile, flexural, Charpy impact and interlaminar shear), thermo-mechanical properties (glass transition temperature, storage modulus and crosslink density) and moisture-absorption properties (saturation moisture level and diffusion coefficient) were investigated and compared with samples containing commercially produced epoxidized soybean oil and a synthetic bisphenol A diglycidyl ether-based epoxy control, R246TX cured with a blend of triethylenetetramine and isophorone diamine. Scanning electron microscopy was also performed to investigate the fibre–matrix interface. Epoxidized hemp oil-based samples were found to have marginally superior mechanical, dynamic mechanical and similar water-absorption properties in comparison to samples made with epoxidized soybean oil bioresin; however, both sample types were limited to bioresin concentrations below 30%. Synthetic epoxy-based samples exhibited the highest mechanical, dynamic mechanical and lowest water-absorption properties of all investigated samples. This study has also determined that epoxidized hemp oil-based bioresins when applied to jute fibre-reinforced biocomposites can compete with commercially produced epoxidized soybean oil in biocomposite applications. [ABSTRACT FROM PUBLISHER]