Journal of Research Updates in Polymer Science

Physicochemical Properties of Films from Semirefined Carrageenan/TiO2 Integrated with Cinnamaldehyde Pickering Emulsion for Active Food Packaging

Fri, 02 Feb 2024 00:00:00 +0000

Plastic waste has become a significant global environmental issue, particularly in the context of food packaging. In the present study, active packaging films were fabricated by integrating chitosan-stabilized cinnamaldehyde Pickering emulsion (PE) and titanium dioxide particles (TNPs) into the semirefined carrageenan (SRC) matrix. The impact of cinnamaldehyde PE and TNPs on the physical and mechanical attributes of the SRC films was explored. The integration of TNPs (3%, w/v) and 0.5% cinnamaldehyde PE revealed promising mechanical properties, with 21.86 MPa tensile strength and 34.21% of elongation at break value. The inclusion of TNPs and cinnamaldehyde PE led to enhancements in the moisture content and water solubility of the SRC films. The thermal stability of the film was marginally increased with 0.5% cinnamaldehyde PE. Scanning electron microscopy (SEM) revealed a uniform distribution of active compounds in the SRC matrix. The study findings highlight the potential of cinnamaldehyde PE and TNPs in active food packaging films as eco-friendly alternatives to conventional petrochemical-derived plastics in food packaging.

Evaluation of a Strain Sweep Tests Protocol as a Tool for Assessing the Homogeneity of SBR Copolymer Composition

Harrison Lourenço Corrêa, Cristina Russi Guimarães Furtado — Fri, 29 Mar 2024 00:00:00 +0000

Global competition in products and services demands constant improvement in production systems. Similarly, it is essential for industries to have quality control tools capable of assessing the compliance of a given product at a lower cost and with greater effectiveness. In the rubber and composite industry, where complex formulation and mixing systems can affect not only the quality of the final product but also the processing of rubber, the development of a protocol that assumes this function is important. The present study developed samples of elastomeric blends based on styrene-butadiene copolymer (SBR) with different filler concentrations (30, 60, and 90 phr of ground tire rubber as filler), which were analyzed using an oscillating cavity rheometer (MDpt-TechPro). Based on a proprietary testing protocol, the degree of homogeneity of the composites was evaluated, which was compared with scanning electron microscopy studies. The implemented protocol, which provides results within 30 minutes, proved to be promising for quality control of these blends, and it can be used by rubber processing industries, saving both time and cost, being an unprecedented study on the 'homogeneity-rheology' relationship.

Low-Cost Production of Chitosan Biopolymer from Seafood Waste: Extraction and Physiochemical Characterization

Tue, 02 Jul 2024 00:00:00 +0000

Chitosan is an abundant natural biopolymer widely used in industrial and pharmaceutical applications. It stands out for its remarkable biodegradability, biocompatibility, and versatility. Herein, we tried to extract chitosan from mud crab (Scylla spp.), a seafood waste abundantly found in Bangladesh’s growing crab farming industry, via a simple low-cost production route. At first, chitin was extracted from crab shells through demineralization and deproteinization to eliminate minerals and proteins. The chitosan biopolymer was then obtained by deacetylation of purified chitin. To evaluate its physicochemical properties, the as-prepared chitosan was characterized by different analyses, such as water and fat binding capacity, solubility, viscosity, molecular weight, fourier transform-infrared, thermogravimetric, scanning electron microscopy, and ash content analysis. The results showed that the crab shell contains around 26.8% chitosan by dry weight, making it an excellent raw material for the massive production of the natural biopolymer chitosan. The prepared chitosan showed fat and water binding capacities of 200-300% and ~680.9%, respectively. Furthermore, it was highly soluble in 1% acetic acid and had an ash content of about 33.7%. Convincingly, the produced chitosan showed great physiochemical properties making it suitable for biomass efficiency, sustainable development, revenue generation, and biomedical applications. In addition, the recycling of seafood waste into a valued product is beneficial to help keep the environment clean, which is among the sustainability goals in Bangladesh and globally.

Synthesis and Applications of Onium Salts for Photopolymerization Reactions

Ideisan I. Abu-Abdoun, Aale-Ali Aale-Ali — Fri, 12 Jul 2024 00:00:00 +0000

The synthesis and characterization of phosphonium and arsonium salts having anthraquinone and anthracene moiety was carried out by reacting equimolar amounts of halomethyl anthracene or anthraquinone with triphenylphosphine or triphenyl arsine in toluene solvent. The halide counter (Cl or Br) ion was exchanged with hexafluoro antimonate (SbF₆^-) which proved to be a useful photoinitiator for polymerizing cyclohexene oxide, styrene, p-methyl styrene, and N-vinylcarbazole. The experimental results demonstrate the effects of salt, monomer structures, and the photolysis time on the rate of polymerization and the number average molecular weight of the obtained polymer. These salts are easy to handle, nonhygroscopic under laboratory conditions, and they have good solubility in halogenated solvents such as dichloromethane and chloroform.

Hemostatic Gelatin-Alginate Hydrogels Modified with Humic Acids and Impregnated with Aminocaproic Acid

Mon, 05 Aug 2024 00:00:00 +0000

The work is devoted to the development of safe and biocompatible multicomponent gelatin-alginate hydrogels modified with humic acids (HA) and impregnated with the antifibrinolytic agent aminocaproic acid (АА).These hydrogels are designed to be effective hemostatic materials with anti-inflammatory properties and the ability to deliver in less than 30 seconds to deep and hidden areas of hemorrhages. Studies of the crystal structure by X-ray diffraction analysis and non-covalent interactions of molecules by Fourier transform infrared spectroscopy of the developed hemostatic gelatin-alginate hydrogels modified with bactericidal and anti-inflammatory humic acids made it possible to identify the optimal concentrations of HA from 2.5 wt.%. up to 5 wt.%. At such concentrations of HA, gelatin-alginate hydrogels have a semicrystalline structure. Due to non-covalent bonds between polymer chains, they are thermo-responsive with a gel-sol transition temperature of about 37 °C. Impregnation of these hydrogels with aminocaproic acid led to an almost threefold increase in their swelling, which facilitated the dissolution of AA in the hydrogels and its subsequent delivery to the wound. Experiments simulating the transmembrane transport of aminocaproic acid from the developed gelatin-alginate hydrogels confirmed their ability to rapidly deliver up to 494± 3 mg of AA from 5 ml of hydrogel to the wound.

Polymers used in Vertebroplasty: The Importance of Material Technology in the Rehabilitation of Osteoporotic Patients

Daniela Gallon Corrêa, Jonas Lenzi de Araújo, Harrison Lourenço Corrêa — Fri, 09 Aug 2024 00:00:00 +0000

Recent statistics show that the human population is tending towards aging. More effective medications and medical-hospital treatments, a more balanced diet, and regular physical activities contribute to longevity with quality of life.However, on many occasions, the natural aging process brings with it some chronic diseases, such as osteoporosis. Characterized by the loss of bone density, it can compromise mobility and even lead to death due to vertebral fractures, among other issues.To mitigate these risks, materials engineering becomes useful for restoring partial and/or total bone structure. In combination with a physiotherapeutic approach, they can rehabilitate the patient, providing them with a better quality of life.The present work aims to discuss the main polymeric materials used for the treatment of osteoporosis in patients with fractures.

Physicochemical and Structural Investigation of Argeli (Edgeworthia gardneri) Bast Fibers

Fri, 09 Aug 2024 00:00:00 +0000

The structure and some physicochemical properties of Argeli (Edgeworthia gardneri) bast fibers were investigated using Fourier Transform Infrared (FTIR) and Energy Dispersive X-ray (EDX) spectroscopies, Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). The neat fibers were found to contain about 54.47% cellulose, 25.98% hemicellulose, 10.5 % lignin, 6.1% extractives, and about 2.9% ash. The fibers on chemical treatments changed several properties, some of them being quite significant. Fiber density was increased by 8.5% in the alkali-treated samples which may be due to the loss of less dense components such as lignin and hemicelluloses. The tensile strength of the fiber increased by 34 % and 61 %, respectively, after alkali and bleaching treatments. However, the thermal properties of treated samples did not change significantly. The mechanical properties of Argeli fiber were improved on chemical treatments making them attractive in the fabrication of polymer composites, textiles, and papers.

Mechanical and Dynamic Mechanical Characterization of Epoxy Composites Reinforced with Casuarina Leaf Bio Fibre

R. Nalini Suja, B. Sridevi, Senthil Muthu Kumar Thiagamani — Wed, 28 Aug 2024 00:00:00 +0000

This study investigates the influence of casuarina leaf biofibre on the mechanical and morphological characteristics of epoxy resin composites. Composites were prepared using the hand-layup method, incorporating varying volume fractions of the biofibre (4%, 8%, 12%, 16%, 20% and 24% v/v). Mechanical and dynamic mechanical tests were carried out to assess the impact of the biofibre on the composite material. Mechanical testing revealed significant enhancements in tensile strength of 29.2 MPa, particularly at a biofibre volume fraction of 12% and the composite with the highest impact and flexural strengths measured at 2621 J/m² and 41.1 MPa, respectively for the 16%v/v fibre loading. Dynamic mechanical analysis (DMA) results demonstrated improved viscoelastic properties attributed to the presence of the biofibre. Scanning electron microscopy (SEM) examination of tensile tested samples provided insights into interfacial bonding and filler dispersion within the composite matrix. Overall, the findings highlight the potential of casuarina leaf biofibre to enhance specific mechanical properties and viscoelastic behaviour of epoxy casuarina composites. Optimizing the biofibre volume fraction offers possibility to tailor composite properties for specific application requirements. This research advances the development of bio-based composite materials, contributing valuable insights for the creation of sustainable and high-performance engineering materials.

Determination of Kinetic Parameters and Thermal Characteristics of Epoxy Casuarina Bio Composites

R. Nalini Suja, B. Sridevi, Senthil Muthu Kumar Thiagamani — Mon, 02 Sep 2024 00:00:00 +0000

By reinforcing casuarina equisetifolia leaf, a flexible bio fibre, in different volume proportions of 4%, 8%, 12%, 16%, and 20% into the epoxy resin, a bio-based composite was produced utilizing the hand layup method. FT IR spectrum was used to verify the production of epoxy casuarina composite. The produced composites have undergone an extensive thermal investigation using Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA), Derivative Thermogravimetric (DTG) study and Differential Scanning Calorimetry (DSC) analysis. It has been observed that increasing the percentage of casuarina fibre content enhances the thermal stability of epoxy resin. Horowitz- Metzger (HM), Broido and Coats-Redfern (CR) models were worked and the result revealed that the decomposition of casuarina epoxy composite followed one Dimensional Diffusion Model with coefficient of correlation value close to 1. The thermodynamic parameters including Activation energy (Ea), frequency factor (A), Gibbs free energy (ΔG), entropy (ΔS) and enthalpy (ΔH) of epoxy casuarina composites were found to increase with increase in fibre contents. This makes the composite more suitable for making high performance engineering material for various applications.

Tribology Behavior of In-Situ FDM 3D Printed Glass Fibre-Reinforced Thermoplastic Composites

Yu Heng Liow, Khairul Izwan Ismail, Tze Chuen Yap — Mon, 02 Sep 2024 00:00:00 +0000

Fused deposition modeling (FDM) 3D-printed parts are generally weaker compared to injection-moulded parts. Fibre reinforcement is one of the techniques used to enhance the mechanical strength and the tribological behavior of the FDM-printed parts. Recently, a new method for creating FDM 3D-printed composites was developed. Current work focuses on the tribological behavior of the glass fibre-reinforced PLA, manufactured using this new composite manufacturing method. Experiments were conducted to investigate the effect of Glass Fibre (GF) reinforcement on FDM 3D-printed thermoplastic composites, specifically polylactic acid (PLA) under different linear sliding speed and directions. All 3D printed glass fibre-reinforced PLA (PLA-GF) composites exhibited a lower wear rate and a higher friction coefficient compared to 3D printed PLA. Increasing in disc’s linear speed or sliding speed of the pins resulted in a lower coefficient of friction and wear rate. In addition, a perpendicular raster direction towards the disc rotation or pin motion experienced greater friction and greater wear.

Innovative Atmospheric Plasma Jets for Advanced Nanomaterial Processing

Maziyar Sabet — Mon, 02 Sep 2024 00:00:00 +0000

This study presents a comprehensive exploration of atmospheric pressure plasma jets (APPJs) as an innovative method for synthesizing and modifying nanomaterials, offering a versatile and efficient approach to tailoring their properties and functionalities. Unlike traditional low-pressure plasma techniques, APPJs operate at ambient conditions, providing significant advantages in scalability, cost-effectiveness, and environmental sustainability. This review delves into the recent advancements in APPJ technology, including the development of microfluidic configurations that enhance plasma generation and control, leading to improved efficiency, power, and user accessibility. These advancements have opened new possibilities in various fields, such as the development of antimicrobial coatings, advanced drug delivery systems, and high-performance solar cells. The ability of APPJs to facilitate precise surface engineering and targeted material deposition positions them as a transformative technology in nanomaterial processing. Despite their potential, challenges such as scalability and environmental impact must be addressed to realize widespread adoption. This study underscores the promise of APPJs in driving future industrial applications and highlights the need for continued innovation to overcome current limitations and unlock their full potential across multiple sectors.

Secondary Thermoplastic Modified Wood-Polymer Composite with Increased Technological, Mechanical and Dielectric Properties

Fri, 20 Sep 2024 00:00:00 +0000

The article describes the development of new formulations of wood-polymer composites with a modified polymer matrix and the study of their technological, mechanical and dielectric properties. The research aim is to create a new composition of wood-polymer composites based on secondary raw materials with an improved set of technological, mechanical and dielectric properties, namely, the modification of the polymer matrix and the development of a new technology for its production. The optimal composition of the polymer matrix and modification influence of the wood-polymer composites polymer matrix on the physical, mechanical and dielectric properties of the samples are determined. Strength, impact resistance, abrasion, mechanical and dielectric properties are studied. A description of the climatic influences on the wood-polymer composites including the influence of moisture and temperature is given.

Itaconic Acid-Based Hydrogels with Flame Retardancy and High-Temperature Resistance via Vat Photopolymerization 3D Printing

Thu, 26 Sep 2024 00:00:00 +0000

Biomass-based hydrogels have received extensive attention due to their flame retardant properties and environmental friendliness. The dilemma that non-renewable energy resources are increasingly depleted, leads us to place high expectations on renewable natural clean energy, as well as to conduct in-depth research on the efficient utilization and green preparation processes for the clean energy. In this study, we introduce a green and sustainable method for the design and preparation of flame-retardant materials by integrating two new class of itaconic acid-based hydrogels in conjunction with the rapid vat photopolymerization (VP) 3D printing technology. The hydrogels prepared by this method exhibit exceptional flame retardancy, mechanical robustness and superior high-temperature resistance. This research provides novel strategies and essential guidance for the green synthesis and sustainable development of next-generation flame retardant materials.

Recent Progress in Hydrogel-Based Bioinks for 3D Bioprinting: A Patent Landscape Analysis and Technology Updates

Fri, 27 Sep 2024 00:00:00 +0000

Hydrogel-based bioinks have emerged as a critical component in the field of three-dimensional (3D) bioprinting, with numerous polymers being explored and utilized for this purpose. The high volume of patent applications reflects a competitive and dynamic research environment, where various entities are actively developing new formulations and applications for hydrogel-based bioinks. As this field continues to evolve, tracking these trends is essential for understanding the future direction of the technology and identifying key innovations and players in the industry. This study reveals substantial growth in the patent landscape for hydrogel-based bioinks in 3D bioprinting, with 173 patent documents published between 2013 and 2024. The marked increase in patent filings, particularly from 2018 onwards, underscores the growing recognition of the technologys potential in diverse applications, including tissue engineering and regenerative medicine. Although patent applications have outpaced granted patents, the steady rise in granted patents indicates the fields maturation and the transition of innovations from concept to legally protected technologies. The leading patent applicants in this domain include both industry leaders and academic institutions. Companies such as Organovo INC and Cellink AB are driving innovation through extensive patent activity, while academic institutions and foundations also make significant contributions, highlighting a robust ecosystem where industrial and academic research propel the technology forward. The global distribution of intellectual property filings in this field is broad, with significant activity in the United States, Europe, and Asia. This diversity in patenting jurisdictions reflects the global interest in advancing bioprinting technologies, particularly for healthcare applications. Patent classifications for hydrogel-based bioinks in 3D bioprinting illustrate the convergence of materials science, biotechnology, and advanced manufacturing. These classifications highlight the diverse applications of bioinks, ranging from tissue regeneration and stem cell therapy to the development of medical devices and multifunctional bioactive materials based on polymers.

Formulation and Evaluation of Vancomycin Loaded Chitosan/Aloe Vera Hydrogel: A Novel Antibacterial Biopolymeric System

Elham Varnaseri Ghandali, Ali Rastegari, Zohreh Mohammadi — Tue, 15 Oct 2024 00:00:00 +0000

The combination of herbal and biopolymeric agents holds significant potential for enhancing wound healing. Aloe vera, known for its anti-inflammatory, antimicrobial, and regenerative properties, has long been used to treat wounds and burns. Chitosan, as a well-known biopolymer, promotes collagen synthesis, fibroblast recruitment and aiding granulation tissue formation. This study explored the formulation of a chitosan/Aloe vera hydrogel loaded with vancomycin, as a potential wound care product. The hydrogel was prepared using chitosan and aloe vera in 1:1 and 1:2 ratios. After homogenization, 1% vancomycin was incorporated. All physical characterizations, drug loading and drug release studies were performed on prepared formulations. Antimicrobial activity also was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, both physical and performance properties of gels were assessed over three months under room temperature and refrigerated conditions. The study found that the gels remained stable, with no changes in color, flowability, uniformity, or viscosity during stability assessments. Both formulations released their entire drug content within two hours when kept at room temperature and in the refrigerator. No signs of separation or degradation were observed over the three-month period, demonstrating the gel’s stability. Formulations showed acceptable antimicrobial activity against both mentioned bacterial strains. In conclusion, the chitosan/Aloe vera gel containing vancomycin showed desirable properties, making it a promising candidate for wound healing. Its antimicrobial activity and ability to support tissue regeneration suggest it as a valuable treatment for accelerating the wound-healing process.

Hemostatic Ability of Thermosensitive Biologically Active Gelatin-Alginate Hydrogels Modified with Humic Acids and Impregnated with Aminocaproic Acid

Thu, 17 Oct 2024 00:00:00 +0000

The article studies the hemostatic ability of thermosensitive biopolymer hydrogels containing 14% by weight of gelatin and 6.4% by weight of sodium alginate, impregnated with a hemostatic agent aminocaproic acid ~0.2 g/ml, with the addition of humic acids with antioxidant, antibacterial, fungicidal and anti-inflammatory properties. Modification of hydrogels with humic acids slightly increases viscosity, but maintains the gel-sol transition temperature close to the physiological temperature of about 37 °C, which allows them to melt on human skin or inside a wound, ensuring the delivery of aminocaproic acid. SEM images showed that the developed hydrogels have a layered internal morphology, which is improved due to better swelling of the hydrogels contained humic acids, which promotes the dissolution of aminocaproic acid inside the hydrogels and its subsequent rapid delivery to the bleeding site when applying a hydrogel dressing. It has been experimentally established that the concentration of humic acids in hydrogels of no more than 5 wt.% promotes blood clotting due to the entry of aminocaproic acid into it from the hydrogels. The aminocaproic acid delivered at physiological temperature from these hydrogels can shorten the blood clotting time to the lower limit of the normal clotting time range. The clotting time of the hydrogel with 5 wt.% humic acid is only 95 s, which confirms its particularly effective hemostatic ability.

Optimising Nanoparticle Dispersion Time for Enhanced Thermomechanical Properties in DGEBA-Based Shape Memory Polymer Composites

Janitha Jeewantha, Jayantha Epaarachchi, Md Mainul Islam — Thu, 17 Oct 2024 00:00:00 +0000

Shape-memory polymers (SMPs) are smart materials that can change shape upon an external stimulus. This phenomenon is called the shape memory effect (SME), which is caused by entropy change due to rapid molecular motion in the polymer segments. Due to the inherently weak thermomechanical properties, use of SMPs is limited in many engineering applications. Therefore, SMPs are often reinforced with fibres and nanoparticles (NPs). NPs offered greater flexibility due to their superior physical, chemical, electrical, mechanical, and thermal properties. However, the homogeneous distribution of NPs is crucial for composition’s stability and enhancement of the base material’s properties. Among the different techniques used for dispersing NPs, ultrasonic irradiation has shown excellent emulsifying and crushing performance. The sonication process is essential for mitigating agglomerates; however, prolonged sonication time probably increases epoxy temperature, micro-bubbles, cavitation, breaking apart molecules and finally degrading the epoxy resin performances. This paper provides critical insight of nanoparticle dispersion into diglycidyl ether of bisphenol A epoxies (DGEBA). DGEBA epoxy resin was added to TiO₂ NPs and sonicated for 60 min with 5 min intervals while the temperature of epoxy was maintained below 60^oC by using a water cooling throughout the sonication process. The process parameters such as amplitude, mode, epoxy volume and the weight percentage of NPs were kept constant. After each sonication step, Fourier-transform infrared spectroscopy (FTIR) was performed using Thermo Scientific™ and analysed through OMNIC™ Professional quantitation software. In accordance with FTIR results, until 30 min of the sonication, DGEBA resin was not degraded. In order to confirm the performances and the reinforcing effect of NPs, thermo-mechanical and shape memory properties were compared with the neat specimen. The outcomes of this research have suggested quick guidance to find optimum NP dispersion time for DGEBA resins, which has been hardly studied before.

Polymer Shaped Punches Produces with Fused Filament Fabrication to Improve Cup Accuracy in Sheet Metal Forming

L. Giorleo, I.K. Deniz, M. Ravelli — Thu, 17 Oct 2024 00:00:00 +0000

Rapid tooling has become an effective solution for reducing time and costs in tool production. In sheet metal forming, polymer tools produced via additive manufacturing offer performance comparable to traditional tools. However, a key challenge in this area is compensating for the radial expansion of polymer tools during the forming process, which leads to reduced accuracy in the produced parts and limits the achievable forming depth. To address this issue, the authors of this study proposed a novel punch design aimed at containing radial expansion, thereby enabling greater drawing depth and improved part accuracy. Different punch geometries were designed with a re-entrant angle varying between 150° and 180°. Numerical simulations were conducted to evaluate the optimal geometry, identifying the 160° angle as the best option to compensate for radial expansion and reduce punch load. Experimental tests were then performed to verify the numerical results, demonstrating the potential of this new design producing cups with higher drawing depth and best radial accuracy.

Effect of Mixing Methods and Black Conductive Fillers on Properties of Natural Rubber Composites

Anal Bhatt, Omprakash Mahadwad, Parimal Parikh — Tue, 22 Oct 2024 00:00:00 +0000

Carbon black, graphite, carbon nanofibers, carbon nanotubes, and metal fillers increase composite conductivity in natural rubber, which is electrically insulating. Depending on dispersion, conductive filler lowers insulating material resistivity. These materials are frequently used for electromagnetic/radio frequency interference (EMI/RFI) shielding, conductive flexible seals gaskets, and conductive mats used to prevent electrostatic damage to electronic devices. These elastomers could be used to make flexible solar cells or mechanical-to-electricity devices. Temperature, mixing time, shear rate, and cross-linking during vulcanization affect rubber electrical conductivity of composite. To study shear rate effects, vulcanizate of Natural Rubber-based composites filled with carbon black, millable carbon fiber powder, and synthetic graphite powder was prepared by open mixing (two roll mill) and close mixing (internal mixer). We compared how shear rate affects cure, stress-strain, and volume resistivity of conductive filler-based Natural Rubber composites. Increment in clearance of two roll mill during addition of rubber additives along with rubber of reduced the shearing force resulted in less dispersive and distributive mixing and stagnant points due to band formation on roll surface compared to intermix where compound movement had no stagnation point and long wings pushed material axially and two nogs pushed material in other chamber. Compared to two roll mill samples, the compound reached every point of the mixing chamber for best homogeneity, reducing cure time and improving stress-strain and volume resistivity.

Rheological, Structural and Melt Spinnability Study on Thermo-plastic Starch/PLA Blend Biopolymers and Tensile, Thermal and Structural Characteristics of Melt Spun Fibers

Thu, 24 Oct 2024 00:00:00 +0000

In this study, rheology, structure and melt spinnability of thermoplastic starch TPS/PLA blend compounds as well as characteristics of melt spun fibers was studied. Thermoplastic starch is further modified with tartaric acid and blends are compatibilized using graft copolymer, maleic anhydride grafted PLA. Results from rheology analysis of compounds shows significantly reduced melt flow rate MFR and reduced viscosity as a result of tartaric acid modification and compatibilization, but the viscosity was increased as TPS_TA content in the blend increased. In addition, storage modulus (G`) and loss modulus (G``) were increased with increasing TPS_TA content in the blends. Fourier transform infrared spectroscopy FTIR analysis confirmed O-H peak shifts and peak intensity changes associated to starch thermosplasticization and further peak shifts associated with more O-H bond breakages due to tartaric acid modification, indicating acid hydrolysis action of tartaric acid which agrees with results from rheology study. Melt spinning trials show the possibility of melt spinning of biopolymer fibers from blends with up to 40%w/w TPS_TA content. The melt spun fibers have diameter in range of 12.0–124.0 μm depending on take up speed and TPS_TA content. Differential scanning calorimetry DSC analysis of melt spun fibers shows glass transition T_g shifts attributed to molecular orientation and rigid amorphous TPS phase formation as well as the occurrence of double melting peaks T_m associated to different crystals resulting from induced crystallization. The overall result from this study shows the possibility of melt spinning thermoplastic starch/PLA blend biopolymers in to fibers, revealing opportunity to utilize starch biopolymer for fiber spinning. Furthermore, the results also show the need for further research engagements to get fibers with better performance.

Investigation of the Influence of Different Filler Contents of Wine Pomace in PBS on Fracture Mechanics Properties

M. Isabell Kleiber, M. Benedikt Hiller, Mengxue Du, Michael Nase — Fri, 25 Oct 2024 00:00:00 +0000

Biobased polybutylene succinate (PBS) represents a promising alternative to petrochemical-based polymers. The use of this biopolymeris limited in many areas by its low resilience against environmental influences. With the help of bio-based stabilizers the thermo-oxidative degradation process can be slowed down. Suitable stabilizing additives are natural antioxidants present in plant extracts with a high flavonoid content, which can be found in grapes, wine and wine by-products.

PBS was modified with two different bio-stabilizers based on wine grape pomace. The highest filler content tested was 20 wt.-%. In addition to improving stability, the additives also impact the polymer’s mechanics. The influence of these functional fillers on the fracture mechanical properties was examined in a quasi-static test. The crack growth was recorded using integrated video monitoring. Based on the results, the corresponding crack resistance curve and tearing modulus were determined depending on filler type and content. Additional optical analysis was used to correlate fracture mechanics and structure.

The two bio-stabilizers based on red (RWP) and white wine pomace (WWP) differs distinctly in terms of their influence on fracture mechanical properties. The Influence of RWPon the fracture toughness is significantly higher than that of WWP. Especially at lower filler contents with RWP, there is a strong increase in the fracture mechanics parameter tearing modulus (T_J) and an increase in the slope of the R-curve. With 5 wt.% RWP DOM the T_J is 13.64 x 10², whereas with WWP Silv a value of only 6.39 x 10² can be achieved. This difference is also reflected in the increase in the R-curves. With 5 wt.% a slope of the fitted R-curve of 265.59 (RWP DOM) and 121.02 (WWP Silv) could be determined with the first derivative. In the optical analysis it was noticeable that the RWP particles were more homogeneously dispersed in the matrix while the WWP filler tended to agglomerate. The inhomogeneous distribution and strong agglomeration tendency can be attributed to a higher sugar content of WWP and a higher particle size distribution. The top cut (D97) of WWP Silv is 62.37 ± 0.05 µm and that of RWP DOM is 51.97 ± 0.09 µm.

Investigation of the Influence of Al2O3 Particles on the Microhardness and Tensile Strength of PA6 Composites

Song Jeng-Huang, Angelo Geo, Sathiyalingam Kannaiyan, Yopi Yusuf Tanoto — Mon, 28 Oct 2024 00:00:00 +0000

Polyamide is a high-performance synthetic plastic known for its strength, durability, flexibility, chemical resistance, and low cost, making it widely used in engineering, automotive, and electrical. However, the surface and mechanical properties can be further enhanced to meet the growing demands of advanced engineering applications. This study aims to investigate the influence of Al₂O₃ particles on the hardness of polyamide 6 (PA6). The Al₂O₃ was mixed with PA6 at weight percentages (wt.%) of 0.3% and 1.5% then were fabricated into composite plates using compression molding and subsequently. As a result, the composites achieved higher microhardness and tensile strength compared to the matrix with increases of 13.3% and 7.3% achieved by incorporating 0.3 wt.% of reinforcement, respectively. This result suggests that Al₂O₃ has the potential to improve the surface properties and mechanical strength of the matrix material.

Experimental Investigations of the Influence of Spent Coffee Grounds Content on PLA Based Composite for 3D Printing

Oumaima Boughanmi, Lamis Allegue, Haykel Marouani, Ahmed Koubaa — Fri, 08 Nov 2024 00:00:00 +0000

Nowadays Fused Deposition Modeling, a widely utilized additive manufacturing technology, is significantly transforming as modern production processes. Beyond basic uses to it role in sustainability, Fused Deposition Modeling offers processing potential for implanting circular economy by reducing virgin materials consumption and enhance the integration of waste food for sustainable 3D printing. This research paper investigated the production of new composite materials based on spent coffee grounds. In addition, PLA and SCG at various contents (0, 3, 5, 10, and 15 wt%) were dried and premixed, then processed into PLA/SCG composite pellets using twin-screw extrusion. These pellets were successfully converted into filaments and subsequently used for 3D printing. The effect of spent coffee grounds in PLA composites was investigated via physical and mechanical analysis of 3D printed samples. Regarding density measurements, results revealed that adding up to 5 wt% of spent coffee grounds increased the density while further additions led to a decrease which due to the printing parameters such as extrusion temperature and nozzle diameter. Considering the mechanical properties, the Young’s modulus increased once the spent coffee grounds content reached 3 wt% and then decreased. In the other hand, there was no enhancement in tensile strength and elongation at break which corroborating with density measurements. This mainly contributed to the changes in mechanical properties caused by printing parameters. This study demonstrates that coffee waste can be used as a filler in environmentally friendly composites for 3D printing, with a maximum SCG content of 15 wt%. This approach not only promotes the reuse of coffee waste but also reduces the cost of traditional PLA filaments.

Obtaining Properties of Polymeric Filaments for 3D Printing from Dinizia Excelsa Ducke Fiber and Copper Nanoparticles

T.S. Santos, J.S. Oliveira, J.S. Cunha, J.C.M. Neto, Waldeir Silva Dias — Wed, 20 Nov 2024 00:00:00 +0000

With many existing contagious diseases, SARS-CoV-2 exemplifies the dangers of emerging infectious diseases, potentially leading to severe acute respiratory syndrome (SARS). In March 2020, the World Health Organization (WHO) declared COVID-19 a pandemic in response to the rapid increase in infections globally. This situation not only highlighted the vulnerability of populations to dangerous pathogens but also underscored the persistent challenges faced by the public health community in preventing and controlling contagious diseases. Furthermore, it led to excessive use of plastics that harm the environment, such as 70% alcohol due to its low cost and ease of use, which increased the use of plastic packaging and its improper disposal. There are studies on bioplastics reinforced with plant fibers, showing good mechanical properties, and using polymer nanocomposites with metal oxide nanoparticles, such as copper, where their incorporation can achieve optical, electronic, mechanical, and antimicrobial enhancements through the filament extrusion process. Therefore, the matrix is not only a support for the nanoparticles but can also improve antibacterial performance and expand the applications of this material to meet different requirements. The objective of this study is to produce, through extrusion, antimicrobial bioplastic filaments (PLA, plant fiber, and copper nanoparticles) for use in 3D printing and evaluate their tensile mechanical properties, Optical Morphology (OM), and Scanning Electron Morphology (SEM). The filaments produced with a plant fiber particle size of 140 µm exhibited superior quality and better mechanical performance, with tensile strengths of 33.63 and 23.83 MPa and elastic moduli of 2.69 and 5.45 GPa compared to those with a particle size of 30 µm.

Nanostructure Polyaniline (PANI) Decorated TiO2 Nanocomposite as Efficient Heterogeneous Catalyst

Fri, 29 Nov 2024 00:00:00 +0000

The paper describes the synthesis of conducting polyaniline-TiO₂(PANI-TiO₂) nanocomposite by chemical oxidative polymerization method using aniline as a monomer. TiO₂nanoparticles were synthesized by sol gel method using TiCl₄ and ethanol. Ultrasound synthesized TiO₂ nanoparticles and nanocomposite were characterized by various spectroscopic techniques UV, FT-IR, XRD, SEM and TGA. The XRD pattern confirms the appearance of sharp diffraction patterns indicating the small sized, high purity TiO₂nano particles are highly agglomerated with spherical morphology. The PANI-TiO₂nanocomposite was employed as a promising heterocyclic, reusable catalyst for most of the organic synthesis. The advantages of this methodology are mild reaction conditions with short reaction time, excellent yields, low loading and reusability of catalyst.

Catalytic Degradation and Antibacterial Activity of Cinnamon-Mediated Green Synthesized Silver Nanoparticles Loaded on Alginate Beads

Dhoha Alshameri, Fatima Al-Hannan, Fryad Henari, G. Roshan Deen — Fri, 13 Dec 2024 00:00:00 +0000

Alginate-silver nanocomposites in the form of spherical beads were prepared using a green approach by using the aqueous extract of cinnamon bark. The nanocomposites were fabricated by a three-step process involving gelation by ionotropic crosslinking, adsorption, and in situ chemical reduction in solution. The rich phytochemicals of the cinnamon bark extract played a dual role as reducing and stabilizing agent in the synthesis of silver nanoparticles of average size of 16 nm. The presence of silver nanoparticles in the nanocomposite was studied using UV-Vis absorption spectroscopy, electron microscopy and energy dispersive x-ray spectroscopy. The morphology of the nanocomposite beads was dense and compact with random distribution of silver nanoclusters. The catalytic property of the nanocomposite beads was evaluated for the degradation of Congo-red dye in the presence of sodium borohydride. The degradation followed pseudo-first order kinetics with a rate constant of 0.012 min^-1 at 23 °C. The activation energy for the degradation process was 27.57 ± 1.5 kJ mol^-1. The thermodynamic parameters such as the enthalpy and entropy changes were evaluated using the Eyring equation and were determined to be 0.123 ± 0.05 kJ mol^-1 and -197.25 ± 2 J mol^-1 K^-1, respectively. The nanocomposite exhibited antibacterial properties against the two strains of bacteria, Escherichia coli and Staphylococcus aureus.

Investigation on Acoustic and Thermal Properties of Powdered Granular Mask (PGM) Reinforced Green Epoxy Composites

Thu, 19 Dec 2024 00:00:00 +0000

This study investigates the acoustic and thermal properties of powdered granular mask (PGM) reinforced green epoxy (GE) composites, with PGM contents of 30 vol.%, 40 vol.%, and 50 vol.%. The aim is to develop sustainable, high-performance materials with enhanced insulation properties. Among the samples, S4 (PGM/50 vol.% GE) exhibited the highest Noise Reduction Coefficient (NRC) of 0.30, demonstrating excellent acoustic shielding. Increasing the GE content improved the Transmission Loss (TL) by densifying the composite structure, significantly enhancing sound attenuation. In the high-frequency range, S2 (PGM/30 vol.% GE), S3 (PGM/40 vol.% GE), and S4 recorded TL peaks of 39.3 dB, 43.5 dB, and 44.9 dB at 1372 Hz, 1552 Hz, and 1544 Hz, respectively, confirming improved acoustic performance with higher PGM content. Thermal stability also increased with higher GE content, with S4 showing the highest decomposition inflection temperature of 472°C, indicating enhanced heat resistance. The novelty of this work lies in the dual functional benefits of PGM/GE composites, which offer both superior acoustic insulation and thermal stability. These properties make the composites ideal for aircraft flooring systems, particularly in areas such as cockpits and passenger cabins, where both sound insulation and thermal control are critical. The findings underscore the potential of PGM/GE composites for sustainable, high-performance applications requiring both acoustic and thermal management.

Thermal Cure Kinetics of Modified Cold-Setting Melamine-Urea-Formaldehyde Resins with Liquid Thickeners

Kyle J. Sereni, Jaewook Lee, Byung-Dae Park — Fri, 27 Dec 2024 00:00:00 +0000

Cold-setting melamine-urea-formaldehyde (CS-MUF) resins being used as adhesives for manufacturing laminated wood timber products require to have a proper viscosity using thickener or filler. However, studies on thermal curing kinetics and behavior of the modified CS-MUF resins with liquid thickener are limited. Hence, this study focuses on the thermal cure kinetics of the modified CS-MUF resins with two liquid thickeners at three addition levels to obtain the resin viscosities of 4,000 mPa.s, 8,000 mPa.s and 12,000 mPa.s. Differential scanning calorimetry (DSC) was used to estimate cure kinetics of the modified CS-MUF resins using two analysis methods: 1) model-fitting (MFT) method containing the Kissinger (KSNG) analysis, and 2) model-free (MFK) methods containing Kissinger-Akahira-Sunose (KAS) analysis, and nonlinear isoconversional (VYA) analysis. The KSNG, KAS, and VYA analysis showed that all modified CS-MUF resins followed very similar curing behavior with small difference, except Resin #2 which followed the autocatalytic reaction model based on the Málek method. These results suggest that liquid thickeners increase to a proper viscosity of CS-MUF resins without major impact to their curing behavior.