Higher Storage Modulus Research Articles

Effects of cellulose diameter on the formation and rheological properties of edible walnut oleogels structured by cellulose nanofiber

Oleogel of edible vegetable oils structured by cellulose nanofiber (CNF) via emulsion-templated method has attracted many interests due to its potential substitute of saturated or trans-fats in food industry. The gelation mechanism of liquid oil is dominated by different intermolecular non-covalent interactions, while the type and strength of these interactions are greatly influenced by the structure and properties of the gelator factors. Here, the effect of different CNF diameter ranges (5–10 nm, 10–20 nm and 20–60 nm) was investigated for CNF-based walnut oil oleogels, under the same fiber length and surface carboxyl content of CNFs. The results showed that CNFs with diameters of <20 nm exhibited better emulsification properties, and effectively restrained droplet size increasing and aggregation, compared to CNF with diameter of 20–60 nm. The resultant oleogels with smaller CNF diameter exhibited higher oil-binding capacity (OBC, ∼85%) and better thermal stability of the resultant oleogels. More compact structure and stronger mechanical strength of oleogels were achieved with CNF diameters of <20 nm, which was verified by stronger textural hardness of the oleogels (0.46 N), as well as higher storage modulus (up to 1.1 × 105 Pa) and apparent viscosity in rheological measurement. The enhanced OBC and structure strength of oleogels with smaller CNF diameter could be attributed to the enhanced hydrogen bonding interactions between CNF molecules and CNFs with oil molecules during oleogelation, as the rigorously fibrillation exposed more surface hydroxyl groups as accessible hydrogen bonding sites during CNF preparation. This study improved the understanding about gelling properties of CNFs with different fiber diameters and provided an empirical basis for the construction of CNF-based oleogels with tunable hydrogen bonding interactions.

Investigating the complete replacement of conventional fat with oleogel on the structural behavior of five different pastry products

Saturated and trans fat intake have been linked to an increased risk of developing diseases such as cardiovascular and coronary heart disease, obesity, and myocardial infarction. As a result of the actions and regulations proposed to reduce and eliminate the content of saturated and trans fats, it is necessary to develop and implement new structuring technologies, such as oleogelation. Oleogelation is a promising strategy for structuring liquid oil, that allows the incorporation of vegetable oils rich in unsaturated fatty acids into food matrix and which can provide the functionality of solid fats and improved nutritional characteristics. The partial or total replacement of conventional fats with oleogels in pastry products is of great interest due to their larger consumption. In this research paper, the puff (jam-filled puff pastry) and tender pastries (bow tie cookies, cheese crackers, apple pie, and cookies) have been reformulated by totally replacing of conventional fats with oleogel and the structural behavior in the dynamics of the technological process was evaluated. The textural properties of oleogel were comparable to those of some conventional fats, but frequency sweep measurements showed that the oleogel formulated with refined sunflower oil and carnauba wax (10% w/w) had the highest storage modulus G’ and loss modulus G’’ values when compared to conventional fats (commercial margarine, butter, a mixture of 73% margarine and 27% lard, and puff pastry margarine). The textural properties of oleogel (2.34 N and 2.30 mJ) were significantly different from those of puff pastry margarine (9.78 N and 21.73 mJ), but compared to other conventional fats, the values of hardness (1.42–2.70 N) and adhesiveness (4.40–5.17 mJ) were similar. For conventional and oleogel doughs the storage modulus (Gʹ) were higher than loss modulus (G″) and both increased with the applied frequency (Hz). In terms of the products textural profile, the prototypes formed with oleogel exhibited lower hardness values (2.37–15.64 N) than the conventional products (8.83–19.89 N), indicating the tenderizing effect produced by the oleogel. The fat losses determined during 14 days of storage showed a lower physical stability of the doughs and products formulated with oleogel, most probably due to the destabilization kinetics of the lipid system during the operations of the technological process.

Effect of starch and peanut oil on physicochemical and gel properties of myofibrillar protein: Amylose content and addition form

Starch and peanut oil (PO) were widely used to improve the gel properties of surimi, however, the impact mechanism of addition forms on the denaturation and aggregation behavior of myofibrillar protein (MP) is not clear. Therefore, the effect of starch, PO, starch/PO mixture, and starch-based emulsion on the physicochemical and gel properties of MP was investigated. The results showed that amylose could accelerate the aggregation of MP, while amylopectin was conducive to the improvement of gel properties. The addition of PO, starch/PO mixture, or starch-based emulsion increased the turbidity, solubility, sulfhydryl content of MP, and improved the gel strength, whiteness, and texture of MP gel. However, compared with starch/PO mixture group, the gel strength of MP with waxy, normal and high amylose corn starch-based emulsion increased by 22.68 %, 10.27 %, and 32.89 %, respectively. The MP containing emulsion had higher storage modulus than MP with starch/PO mixture under the same amylose content. CLSM results indicated that the oil droplets aggregated in PO or starch/PO mixture group, while emulsified oil droplets filled the protein gel network more homogeneously. Therefore, the addition of starch and PO in the form of emulsion could effectively play the filling role to improve the gel properties of MP.

Performance Enhancement of Silicone Rubber Using Superhydrophobic Silica Aerogel with Robust Nanonetwork Structure and Outstanding Interfacial Effect.

The application of high-performance rubber nanocomposites has attracted wide attention, but its development is limited by the imbalance of interface and network effects caused by fillers. Herein, an ultrastrong polymer nanocomposite is successfully designed by introducing a superhydrophobic and mesoporous silica aerogel (HSA) as the filler to poly(methyl vinyl phenyl) siloxane (PVMQ), which increased the PVMQ elongation at break (∼690.1%) by ∼9.3 times and the strength at break (∼6.6 MPa) by ∼24.3 times. Furthermore, HSA/PVMQ with a high dynamic storage modulus (G'0) of ∼12.2 MPa and high Payne effect (ΔG') of ∼9.4 MPa is simultaneously achieved, which is equivalent to 2-3 times that of commercial fumed silica reinforced PVMQ. The superior performance is attributed to the filler-rubber interfacial interaction and the robust filler-rubber entanglement network which is observed by scanning electron microscopy. When the HSA-PVMQ entanglement network is subjected to external stress, both the HSA and bound-PVMQ chains are synergistically involved in resisting structural evolution, resulting in the maximized energy dissipation and deformation resistance through the desorption of the polymer chain and the slip/interpenetrating of the exchange hydrogen bond pairs. Hence, highly aggregated nanoporous silica aerogels may soon be widely used in the application of reinforced silicone rubber or other polymers shortly.

Effects of molecular entanglements in amylopectin on the anti-thixotropy, gel properties and viscosity properties

Amylopectin with different side chain architecture and distribution were prepared by ɑ-amylase (AM) and maltogenic α-amylase (MA). The purpose of the study was to investigative the effect of molecular entanglement on the anti-thixotropy, gel properties, water distribution and viscosity properties. The results showed that MA specificity hydrolyzed chains ranging from DP 10–17 while retaining the long internal chains, while AM tended to trim the relatively longer chains of DP ≥ 12. The special (ŋsp) in a double-logarithmic plot versus concentration exhibited two linear regions with changes of gradient at AM-M and MA-M polymer concentrations of about 6.20% and 1.31% (w/v), respectively. Higher storage modulus (G′) and final viscosity, and lower frequency dependence indicated the stronger gels of waxy maize starch were formed by MA modification, despite exhibiting a similar thixotropic loop area to AM samples. The microstructure of MA gels showed a more compact honeycomb-like network structure observed by SEM. These results confirmed the chain length profile of the amylopectin pruned by MA was more conducive to produce anti-thixotropic starch-based material. This study is beneficial to provide insights for customizing starch skeleton structure to meet specific industrial application requirements of starch-based products, especially where the rheological properties need to be precisely controlled.

Mechanically Tough and Conductive Hydrogels Based on Gelatin and Z-Gln-Gly Generated by Microbial Transglutaminase.

Gelatin-based hydrogels with excellent mechanical properties and conductivities are desirable, but their fabrication is challenging. In this work, an innovative approach for the preparation of gelatin-based conductive hydrogels is presented that improves the mechanical and conductive properties of hydrogels by integrating Z-Gln-Gly into gelatin polymers via enzymatic crosslinking. In these hydrogels (Gel-TG-ZQG), dynamic π-π stacking interactions are created by the introduction of carbobenzoxy groups, which can increase the elasticity and toughness of the hydrogel and improve the conductivity sensitivity by forming effective electronic pathways. Moreover, the mechanical properties and conductivity of the obtained hydrogel can be controlled by tuning the molar ratio of Z-Gln-Gly to the primary amino groups in gelatin. The hydrogel with the optimal mechanical properties (Gel-TG-ZQG (0.25)) exhibits a high storage modulus, compressive strength, tensile strength, and elongation at break of 7.8 MPa at 10 °C, 0.15 MPa at 80% strain, 0.343 MPa, and 218.30%, respectively. The obtained Gel-TG-ZQG (0.25) strain sensor exhibits a short response/recovery time (260.37 ms/130.02 ms) and high sensitivity (0.138 kPa-1) in small pressure ranges (0-2.3 kPa). The Gel-TG-ZQG (0.25) hydrogel-based sensors can detect full-range human activities, such as swallowing, fist clenching, knee bending and finger pressing, with high sensitivity and stability, yielding highly reproducible and repeatable sensor responses. Additionally, the Gel-TG-ZQG hydrogels are noncytotoxic. All the results demonstrate that the Gel-TG-ZQG hydrogel has potential as a biosensor for wearable devices and health-monitoring systems.

Investigation on the Correlation between Biaxial Stretching Process and Macroscopic Properties of BOPA6 Film.

Biaxially oriented polyamide 6 (BOPA6) films were prepared by extrusion casting and biaxial stretching with polyamide 6. The effects of different biaxially oriented on the macroscopic properties of BOPA6 were investigated by characterizing the rheological, crystallization, optical, barrier and mechanical properties. The results show that the increase of stretching temperature leads to the diffusion and regular stacking rate of BOPA6 chain segments towards crystal nuclei increases, the relative crystallinity increases, reaching 27.87% at 180 °C, and the mechanical strength and optical performance decrease. Heat-induced crystallization promotes the transformation of β-crystals to α-crystals in BOPA6, resulting in a more perfect crystalline structure and enhancing oxygen barrier properties. BOPA6 chains are oriented, and strain-induced crystallization (SIC) occurs during the biaxial stretching. Further increasing the stretch ratio, the relative crystallinity increased to 30.34%. The machine direction (MD) and transverse direction (TD) tensile strength of BOPA6 (B-33) are nearly two times higher than the unstretched film, reaching 134.33 MPa and 155.28 MPa, respectively. In addition, the permeation decreases to 57.61 cc·mil/(m2 day), and the oxygen barrier performance has improved by nearly 30% compared to the sample B-22. BOPA6 has a high storage modulus at a high stretching rate (300%/s). Rapid chain relaxation would promote the molecular chain disorientation, destroy the entangled network of the molecular chain, and lead to a decrease in tensile strength, reducing to about 110 MPa.

3D printing of low carbon steel using novel slurry feedstock formulation via material extrusion method

Conventional 3D metal printing methods, such as laser sintering and binder jetting are often associated with high initial capital costs that make them inaccessible to many consumers. In this article, an economical alternative approach to 3D metal printing is presented, which uses a slurry-based formulation with the material extrusion method. This method involves a novel slurry feedstock of metal powder and liquid binder, which can be printed at room temperature to form green samples without the need for equipment such as a laser source, binder jetting head, or heated nozzle. It is followed by a thermal treatment process to fuse the printed samples into a metal article. The slurry is prepared by blending carbon steel powder with a cellulose derivative binder and additives. Rheological behaviours of different metal contents and binder concentrations are being investigated to determine the optimum printable slurry formulation. It is found that the optimum slurry feedstock formulation comprises 45 vol% metal content, 54 vol% cellulose derivative binder solution at a concentration of 300 g/L, and 1 vol% defoamer. The resulting slurry has fast-drying shear-thinning behaviour and a high storage modulus of 4 × 107 Pa to sustain the printed article at room temperature. The printed articles exhibited an average linear shrinkage of 12.36%, with less than a 1% linear shrinkage difference between X, Y, and Z directions after thermal treatment. The measured densities of the sintered articles were 95% ± 2% compared to the ASTM B783 (material code F-0000). The sintered articles have a measured carbon content of 0.28 ± 0.02%, hardness of 64.15 ± 9 HV, ultimate tensile strength of 255.33 MPa and Young's modulus of 130.47 GPa. This work demonstrates the viability of this additive manufacturing method in producing metal parts with comparable properties to conventional manufacturing.

Enzymatic synthesis of furan-based copolymers: Material characterization and potential for biomedical applications.

Today's growing demand for advanced and sustainable polyester materials is driven by an increasing awareness of the environmental impact of traditional materials, emphasizing the need for eco-friendly alternatives. Sustainability has become central in materials development, including the biomedical area, where biobased and environmentally friendly solutions are a rapidly growing field. This research aims to comprehensively evaluate a new enzymatically catalyzed furan-based copolymer, poly(decamethylene furanoate)-co-(dilinoleic furanoate) (PDF-DLF), with a 70-30 wt% hard-to-soft segment ratio. Then, its performance across medical applications is explored, with a particular focus on its potential as a nanofibrous scaffolding material. PDF-DLF was synthesized from biobased monomers using Candida antarctica lipase B (CAL-B) as the biocatalyst. Material characterization included dynamic mechan‑ical thermal analysis (DMTA) to assess the mechanical behavior and thermal properties. Enzymatic degradation studies determined biodegradability, while cytotoxicity tests established in vitro biocompatibility. The copolymer was electrospun into nanofibers, with scanning electron microscopy (SEM) employed to analyze their morphology. PDF-DLF displays mechanical and thermal properties indicating high storage modulus and 2 main temperature transitions. Enzymatic degradation studies and cytotoxicity assessments confirm biodegradability and in vitro biocompatibility. Electrospinning successfully transformed the copolymer into nanofibers with diameters ranging from 500 nm to 700 nm. This study significantly advances our understanding of sustainable polyesters with versatile processing capabilities. The successful electrospinning highlights its potential as a biodegradable scaffold for medical engineering, supported by biocompatibility and sufficient mechanical properties. It opens new opportunities for sustainable materials in critical biomedical industries, including tissue engineering.

Guar gum assisted synthesis of high‐quality silver nanoplates and their polyimide matrix nanocomposites for electromagnetic interference shielding applications

AbstractTwo‐dimensional (2D) silver nanoplates are chemically synthesized in the presence of guar gum – a naturally occurring biopolymer. The polymer directs anisotropic growth of silver nuclei into high aspect ratio nanoplates spanning 4500 ± 500 nm lateral length with thickness as small as 40 ± 10 nm. After a thorough investigation of the reaction parameters (temperature, precursor to reductant ratio, and polymer quantity) on the morphology of the product, a scalable synthetic protocol to achieve good yields (95%–98%) of highly pure (~100%) 2D silver nanoplates (AgNPls) in a facile, inexpensive, room temperature, aqueous phase chemical reaction of only about 5 min is devised. The optimized AgNPls induce appreciable conductivity of 5.5 ± 0.38 S/cm in polyimide at only 12 wt% loading. Consequently, the resulting polymer nanocomposite (containing 12 wt% AgNPls), at only 130 ± 15 μm thickness and 0.45 g/cm3 density, effectively blocks electromagnetic radiation in X‐band with a total shield effectiveness of about 10 dB resulting in substantially high specific shielding effectiveness and absolute shielding effectiveness of 22.48 and 1729.23 dB cm3 g−1, respectively. Additionally, the nanocomposites remain thermally stable up to 500°C in oxidative environment and possess an appreciably high storage modulus of 3.113 GPa at 50°C. These low‐density conductive polyimide films, therefore, present great prospects in shielding against electromagnetic interference under extreme conditions.

Diazirine-Functionalized Polyurethane Crosslinkers for Isocyanate-Free Curing of Polyol-Based Coatings.

Polyurethane coatings have strong material properties due to the hydrogen bonding inherent to the urethane groups. However, installing this urethane moiety usually requires curing through difficult-to-handle isocyanates. In this work, we show the development of a polyurethane-based crosslinker that can be used to formulate a one-component polyurethane coating with material properties similar to those of isocyanate-based polyurethane coatings. To achieve this, we used diazirine functionalities that generate carbenes upon heating, which react with alcohol functionalities in a polyol to generate a crosslinked network with a high storage modulus.

Physical characterization, biocompatibility, and antimicrobial activity of polyvinyl alcohol/sodium alginate blend doped with TiO2 nanoparticles for wound dressing applications

The ability of wound dressing materials to tackle skin pathogens colonization that is associated with open wound infections is limited. Recently, green-synthesized metal oxide nanoparticles has received a lot of attention to overcome this limitation. However, titanium dioxide nanoparticles (TiO2-NPs) exhibit exceptional antibacterial properties. In this work, several concentrations (0, 1, 3, and 5 wt.%) of TiO2 NPs prepared using Aloe vera leaf extract were added to a blend of polyvinyl alcohol and sodium alginate (PVA:SA). This nanocomposite was designed to enhance the healing process of wounds. The interaction between the PVA:SA composite and the TiO2 NPs was confirmed by FTIR. The thermal behavior of the nanocomposite films was investigated using DSC and TGA. The experimental results indicate that the glass transition temperatures of the nanocomposites increased by increasing the added amount of TiO2 NPs to be 53.7 °C (1 wt.%), 55.8 °C (3 wt.%), and 60.6 °C (5 wt.%), which were consistently lower than the glass transition temperature of the matrix material (69.6 °C). The Dynamic Mechanical Analysis was examined. The nanocomposite doped with 5 wt.% of TiO2 NPs detected a high storage modulus (21.6 × 108). Based on swelling and degradation studies, the prepared PVA:SA:TiO2 nanocomposite films have an excellent swelling rate, and the inclusion of TiO2 NPs increases the stability of the polymeric matrix. The PVA:SA:TiO2 nanocomposite films exhibited a superior antibacterial efficacy against Gram-positive bacteria such as Bacillus cereus and Staphylococcus aureus, compared to their effectiveness against Gram-negative bacteria like Escherichia coli. Moreover, the nanocomposite films were biocompatible with Human Skin Fibroblast. Therefore, the developed PVA:SA:TiO2 nanocomposite films suit wound dressing applications.

Investigation of viscoelastic behavior of Abaca-reinforced epoxy composites

Natural fiber-based composites demonstrate excellent and comparable static and dynamic mechanical properties to conventional materials, such as steel and aluminum. They also extend their applications to aeronautical, sports equipment, and marine fields. This experimental study aims to find the effect of untreated and treated Abaca-reinforced epoxy composites on the viscoelastic behavior and the optimum combinations of fiber and resin to produce better bonding efficiency. The different specimens used for this study were pure epoxy, untreated, and chemically treated composite specimens. The four weight percentages of Abaca fibers are 10%, 20%, 30%, and 40% used to prepare composite specimens. Similarly, four different sodium hydroxide (NaOH) concentrations, 4, 6, 8, and 10 wt. %/vol. %, have been used for the chemical treatment of fibers. The storage modulus of Abaca-reinforced epoxy composite specimen has been investigated with respect to temperature and fiber content. The result shows that the 30% weight fraction of fibers with chemically (8 wt. %/vol. %) treated fiber-reinforced epoxy specimen produces 41.67% higher storage modulus than the 10% weight fraction of fibers content of composite specimens. Fourier-Transform Infrared Spectroscopy (FTIR) broad transmittance has been used to distinguish the raw and chemically treated fibers. FTIR results reveal the removal of functional groups after NaOH treatment.

Rhizobial oxidized 3-hydroxylbutanoyl glycan-based gelatin hydrogels with enhanced physiochemical properties for pH-responsive drug delivery

Rhizobial exopolysaccharide (EPS) is an acidic polysaccharide involved in nitrogen fixation-related signal transduction in the rhizosphere, serving as a structural support for biofilms, and protecting against various external environmental stresses. Rhizobial EPS as a hydrogel biomaterial was used for a pH-responsive drug delivery system combing with gelatins. Pure gelatin (GA) hydrogels have limited practical applications due to their poor mechanical strength and poor thermal stability. We developed new GA hydrogels using oxidized 3-hydroxylbutanoyl glycan (OHbG) as a polymer cross-linking agent to overcome these limitations. OHbG was synthesized from sodium periodate oxidation of 3-hydroxylbutanoyl glycan directly isolated from Rhizobium leguminosarum bv. viciae VF39. The newly fabricated OHbG/GA hydrogels exhibited 21-fold higher compressive stress and 4.7-fold higher storage modulus (G') than GA at the same strain. This result suggested that OHbG provided mechanical improvement. In addition, these OHbG/GA hydrogels showed effective pH-controlled drug release for 5-fluorouracil, self-healable, and self-antioxidant capacity by uronic acids of OHbG. Cell viability tests using HEK-293 cells in vitro also showed that the OHbG/GA hydrogels were non-toxic. This suggests that the new OHbG/GA hydrogels can be used as a potentially novel biomaterial for drug delivery based on its self-healing ability, antioxidant capacity, and pH-responsive drug delivery.

Evaluating the 3D printability of pearl millet flour with banana pulp blends.

Three-dimensional (3D) food printing is a promising method for developing nutritious snack foods with complex and customized structures. In this study, to develop a pearl millet-based snack formulation, the printability of pearl millet flour (PMF) was assessed, without and with the addition of banana pulp (BP), a natural taste and flavor enhancer, at five different levels (PMF:BP of 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100). The water activity significantly decreased with increases in the proportion of BP; higher water activity was exhibited at 100:0 (0.99). The BP proportion influences all the color values (redness: 2-11; yellowness: 17-31.87; total color difference: 2-17). All formulations exhibited shear-thinning behavior (n = 0.02-0.49) and higher hardness (0.2-0.4 N), but not all were printable. A significant decrease in adhesiveness (-0.2 to -0.03 N s) and higher storage modulus (2000-6000 Pa) occurred with an increased proportion of BP. Findings from detailed rheological behavior assessment (static, dynamic and three-interval thixotropy tests) better correlated with trends observed during 3D extrusion printing. The highest yield stress was attained (80 Pa) in the 100:0 formulation. From the thixotropy test, more deformation (>80%) and recovery (>100%) were attained by three of the formulations (100:0, 80:20, 60:40). Overall, the best constructs were obtained (based on the visual sensory characteristics) for the 60:40 formulation printed at 600 mm min-1 printing speed and 240 rpm extrusion motor speed through a 1.22 mm nozzle. The findings of this work will provide valuable insights into the development of novel millet-based 3D printed foods. © 2024 Society of Chemical Industry.

Enhanced printability of food-grade edible inks: Emulsions formulated with modified pea protein and sodium alginate

The 3D printing of foods has grown in interest recently due to its ability to create customized or personalized food products. This study focused on the creation of stable high internal phase Pickering emulsions (HIPPEs) for application as edible inks in 3D food printing. These concentrated oil-in-water emulsions were innovatively prepared using modified pea protein isolate (PPI) and sodium alginate (SA) complexes as stabilizers. Pea protein isolate was used in its commercial form (C-PPI) or in a high-pressure homogenized and ultrasonically modified form (HU-PPI). Four types of stabilizers were used to formulate the HIPPEs: C-PPI, HU-PPI, C-PPI-SA, and HU-PPI-SA. The particle size, microstructure, rheology, stability, and 3D printability of the resulting emulsions were characterized. HIPPEs formed using HU-PPI-SA complexes had the smallest particle diameters (<50 μm), as well as a more compact microstructure than those formed using the C-PPI-SA. Rheologically, the HU-PPI-SA stabilized HIPPEs had a higher storage modulus (500 Pa) and apparent shear viscosity (1000 mPa·s), which enhanced their 3D printability. Shapes printed with these emulsions maintained their structural integrity for up to 24 h, indicating the potential of HU-PPI-SA stabilized HIPPEs as edible inks for 3D food printing applications because of their enhanced stability, printability and rheological properties. This study provides new information that could facilitate the development of edible inks that combine good printability and nutritional value to achieve customized nutrition and efficient industrial food production.

Effect of thermal modification of wood on the rheology, mechanical properties and dimensional stability of wood composite filaments and 3D-printed parts

ABSTRACT This study investigates the effects of thermal modification (TM) on wood-filled polylactic acid composite filaments for 3D printing. Nine composite formulations with different wood content were analysed. The wood particles came from unmodified and thermally modified beech wood (180 °C or 200 °C). The results showed that the incorporation of thermally modified (TMd) wood changed the filament properties, resulting in lower density and reduced surface roughness. The 3D-printed parts with TMd wood particles had a higher water contact angle, higher storage modulus, lower glass transition temperature, higher modulus of elasticity and higher indentation hardness. However, the tensile strength of the 3D-printed parts decreases, even though the results of parts with TMd wood showed higher strength compared to unmodified wood at the same filler content. Surprisingly, TMd wood had no effect on water absorption under humid conditions. Scanning electron micrographs showed improved interfacial adhesion between TMd wood particles and PLA, with smaller voids in the filament compared to filaments with unmodified wood particles. The study suggests that further research into use of TMd wood particles in composite holds promise for environmentally friendly 3D printing materials with favourable thermal and mechanical properties, impacting the expanding market for sustainable solutions in 3D printing.

Large-scale NiFe2O4-based cermets prepared by composite extrusion modelling: From high-qualified composite feedstock to dense sintered microstructure

Combining with the advantages from mature technologies of fused deposition modelling and powder injection molding, 3D NiFe2O4-based cermet with weight over 1.3 kg and relative density of 95.8 % were fabricated by composite extrusion modelling using polyoxymethylene-based feedstock. Microstructure and rheological properties of the feedstock, roles of printing parameters on the morphology green samples and related catalytic debinding, sintering properties of cermets were investigated in detail. Uniformly dispersed cermet powders in feedstock were confirmed, due to the good wettability between the powders and binders. The feedstock with high solid loading of 58 vol% exhibited shear-thinning behavior and contained high storage modulus for reliable shape retention. With optimized printing parameters, a high compression ratio (layer height/nozzle diameter) over 2.5 tended to shrink the size of stacking pores, resulting in dense green samples. Catalytic debinding was proved to be defect-free and efficient debinding route, which was successfully used to deal with dense cubic samples with thickness of 30 mm. Sintered samples showed uniform microstructure with interconnected FeCuNi and Ni(Fe)Fe2O4 phases. Except for partial stacking pores in the fracture section, polished cermets exhibited mirror-like surfaces, indicating the good controlling of the final microstructure and performance of 3D cermets.

Mechanical, Rheological, and Heat Seal Properties of 1‐Octene Grafted Low Density Polyethylene Films

AbstractHeat seal and mechanical properties of 1‐octene grafted low density polyethylene films containing various concentrations of Dicumyl peroxide as the initiator and 1‐octene grafting agent is investigated through using experimental measurements. The results of differential scanning calorimeter (DSC) measurements revealed that the melting temperature shifts to higher values and the peak of the DSC curve becomes wider with the increase of 1‐octene concentrations. Thermogravimetric analysis (TGA) revealed a higher thermal stability up to 20 °C for 1‐octene grafted PE compared with neat LDPE alloy. The results of stress–strain measurements revealed that the 1‐octene grafted PE alloys has higher tensile strength in comparison with neat PE alloy and samples containing only DCP initiator. The results of heat seal analysis indicated that both DCP initiator and 1‐octene tended to offer a moderate increase peel strength of PE alloy. DMTA measurements for various grafted PE alloys show a higher damping factor in comparison with neat LDPE alloy. Rheological measurements indicated a higher storage modulus up to 25% and higher complex viscosity for grafted PE samples containing 1‐octene comonomer.

Effect of Red Palm Olein and Glutinous Rice Flour Mixture as Fat Replacers on the Physicochemical, Rheological, and Microstructural Properties of Buffalo Meat Emulsion

The present study evaluated the physicochemical, rheological, and microstructural properties of buffalo meat emulsion incorporated with red palm olein (RPO) and glutinous rice flour (GRF) as fat replacers. A total of six different samples were prepared by using combinations of RPO and GRF replacing animal fat viz., control (with animal fat), R1 (100% fat replaced by RPO), R2 (50% fat replaced by RPO), RG (50% fat replaced by 25% RPO and 25% GRF), G1 (100% fat replaced by GRF), and G2 (50% fat replaced by GRF). The samples were analysed for physicochemical parameters, gel strength, rheological and microstructural properties. G1 and G2 samples were recorded with improved emulsion stability, cooking loss, hardness, and chewiness while lowering the fat content. Micrographs of G1 and G2 samples demonstrated a spongy/honeycomb-like structure with roughly spherical crystalline granules. The rheological properties of G1 indicated a more stable emulsion with a higher storage modulus (G’). Using RPO as a fat replacer seemed to produce a lower-quality emulsion. Therefore, replacing the fat with GRF, especially at 100%, is proposed for buffalo meat emulsion.