Biodegradable Composite Materials Research Articles

Investigation on cotton dust-reinforced epoxy composites

A partially biodegradable composite material with cotton dust as reinforcement in epoxy resin matrix has been developed. Composite laminas are prepared with various percentages of untreated and alkali treated cotton dust fiber and their strength and elastic modulus in tension and flexure are determined. Influence of alkali treatment of fibers on mechanical properties of the composite is studied. It is concluded that alkali treatment of fibres has pronounced effect on tensile and flexure properties of the composite.

Facile preparation of flame-retardant cellulose composite with biodegradable and water resistant properties for electronic device applications

The aim of the present study is to produce flexible, flame-retardant, water-resistant and biodegradable composite materials. The ultimate goal of this research is to develop simple processes for the production of bio-based materials capable of replacing non-degradable substrates in printed circuit board. Cellulose was chosen as a renewable resource, and dissolved in 1-ethyl-3-methylimidazolium acetate ionic liquid to prepare a cellulosic continuous film. Since flame retardancy is an important criterion for electronic device applications and cellulose is naturally flammable, we incorporated ammonium polyphosphate (APP) as a flame-retardant filler to increase the flame retardancy of the produced materials. The developed material achieved a UL-94 HB rating in the flammability test, while the cellulose sample without APP failed the test. Two hydrophobic agents, ethyl 2-cyanoacrylate and trichloro(octadecyl)silane were applied by a simple dip-coating technique to impart hydrophobicity to the cellulose-APP composites. Dynamic mechanical analysis indicated that the mechanical properties of the cellulosic materials were not significantly affected by the addition of APP or the hydrophobic agents. Moreover, the biodegradability of the cellulosic materials containing APP increased owing to the presence of the cellulase enzyme. The hydrophobic coating slightly decreased the biodegradability of cellulose-APP, but it was still higher than that of pure cellulose film.

Biodegradable Composite Materials based on Cassava Starch and Reinforced with Topinambur (Helianthus tuberosus) Aerial Part Fiber

Biodegradable Composite Materials based on Cassava Starch and Reinforced with Topinambur (Helianthus tuberosus) Aerial Part Fiber

Biodegradable Materials Used in FDM 3D Printing Technology: A Critical Review

Abstract: Three-dimensional (3D) printing is a flexible technique that has attracted increasing interest in recent years. 3D printing has powerful biodegradable materials that are important for environmental protection and emergencies such as COVID-19. To achieve better compatibility for customized and enhanced material characteristics, a variety of ways have been used. Companies and researchers are increasingly interested in biodegradable polymers and composites due to their easy production, eco-friendly, and suitability for a variety of applications. One small step toward protecting the world around us is the use of natural resources to produce fully or partially biodegradable composite materials. PHA (Polyhydroxyalkanoates), PLA (Polylacticacid), High impact polystyrene (HIPS), and PHB (Polyhydroxybutyrates) are examples of bioplastics that are produced and have similar functionality to conventional plastics while also being biodegradable. These materials have the potential to reduce our reliance on petroleum-based plastic, which may present environmental risks. Every country desperately needs to develop bioplastic usage and proper waste management for a pollution-free world. This review is expected to provide a general overview for 3D-printed biodegradable polymer and their applications using fused deposition modelling (FDM) technology.

Effect of hemp bio composite strengthening on masonry barrel vaults damage

Masonry vaults are common structural elements of the Italian architectural heritage, significantly vulnerable to seismic loads. For this reason strengthening is often required. In the last decade, the use of traditional reinforcement techniques has been progressively replaced by Fiber Reinforced Polymers (FRP) bonded at the vault extrados/intrados. However, this approach has shown drawbacks mainly associated to the polymeric nature of matrix and physical compatibility between the matrix and the masonry support. Consequently, FRP strengthening evolved to innovative composite materials obtained by cement based matrix, i.e. Fiber Reinforced Cementitious Matrix (FRCM). Moreover, within the growing environmental sustainability issues, the scientific research is focusing on the development of biodegradable composite materials, based on vegetal fibers and natural matrices. This paper presents the results of experimental tests on two full-scale masonry vaults with the same geometry and mechanical properties: one is unreinforced and one is reinforced at the extrados by continuous bidirectional hemp ropes bonded in a layer of cocciopesto matrix (i.e. a mix of ground clay bricks and organic binder). The two models were built and tested in the 3D shaking table system of the Laboratory of Earthquake Engineering and Dynamic Analysis (LEDA) at Enna Kore University. Each vault was subjected to seismic loads and dynamic identification tests: the seismic load was given with increasing amplitude at the base of the two models while the dynamic identification tests were carried out after each seismic sequence in order to evaluate the variation of the dynamic properties, testifying structural damage. The strengthening effectiveness was assessed by comparing the damages detected on the unreinforced and reinforced masonry vaults. Results showed that the proposed bio composite strengthening material is effective for improving the seismic performance of masonry vaults.

Study on modified poplar wood powder/polylactic acid high toughness green 3D printing composites

In order to alleviate environmental pollution and the shortage of petroleum resources, improve the utilization of renewable materials, the research of biodegradable green composite materials has become a research hotspot. In this paper, Poplar Wood powder(PWP) and Polylactic acid(PLA) were selected, adding poly lactic acid graft maleic anhydride (MPLA) and Silane coupling agent KH-550 (KH550) as a compatibilizer and coupling agent to improve interface compatibility, at the same time, poly Butylenedioate-co-terephthalate (PBAT) and poly Butylene Succinate (PBS) were added to improve the toughness of the composites. The experimental results show that, the impact strength of 20 %-KMPP/PBAT/PBS composite modified by MPLA and KH550 was 20.70 kJ/m−2. Secondly, the hydrophobic angle of the composite material is as high as 112°. It is found that the high content of PWP with small particle size (200 mesh) can make it more evenly dispersed in the composite material, and the cross section of the composite material was smooth. The modified composite was 4.24$/kg, which reduced the cost by 28.07 %. The research results have opened up a new way to develop 3D printed biomass composites with low cost, high compatibility, high toughness and good environmental adaptability, and broadened the application scope and value of the composites.

Biodegradable Composite Materials Based on Potato Starch and Polyvinyl Alcohol

The design and production of biodegradable composite materials that are similar to polymers from petroleum products in performance characteristics, but at the same time have a biodegradable ability, is one of the ways to solve the environmental problem associated with the polymer waste disposal. Scientists around the world are conducting research on obtaining a biodegradable composite material from organic raw materials. The composition development of composite materials includes the optimal ratio selection of fillers, plasticizer and solvent. The material preparation technology involves the raw materials preparation, the mixing order at given temperatures, and the suspension drying until a film structure is formed. The study aimed at preparing samples of biodegradable composite materials based on potato starch and polyvinyl alcohol in different ratios and to study their structure, water absorption, vapor permeability, and mechanical properties. As a result of processing the experimental data, the authors determined that sample of a biodegradable composite material with a 5:1 ratio of starch and polyvinyl alcohol had the best values for water absorption and vapor permeability. Sample 4 demonstrated the best strength characteristics values (a 4:2 ratio of starch and polyvinyl alcohol). There are microphotographs of surface samples in the work, proving the fact that for samples containing potato starch and PVA in 5:1 and 5:2 ratio, the surface is more uniform, the amount of seals is small. Decrease in the polyvinyl alcohol content leads to the increase in the surface defects number. A man can use the resulting biodegradable composite materials to the film packaging materials development to solve environmental problems with the polymer waste disposal.

Characterization of Natural Fiber Extracted from Corn (Zea mays L.) Stalk Waste for Sustainable Development

Corn stalk fibers were extracted from corn stalk using sodium hydroxide for textile application. The extraction conditions were optimized on the basis of the quality and quantity of extracted fibers. The optimum conditions were obtained by treating corn stalk with 5 g/L concentration of sodium hydroxide for 60 min at boiling temperature using a 1:50 material-to-liquor ratio. Extracted fibers were bleached and tested for different physical and chemical properties. Besides these properties, the characterization of extracted fibers was carried out by a scanning electron microscope (SEM), X-ray diffraction analysis (XRD) and Fourier–transform infrared (FTIR) analysis. SEM was used to study the morphological changes in the raw and bleached fibers. The crystallinity changes of the raw and bleached samples were measured with an X-ray diffractometer by peak height method. FTIR was used to examine the compositional changes in the bleaching process. It was found that raw fibers contained the cellular residues such as lignin and hemicelluloses, which cement the fibers together. The chemical treatments such as alkali and bleaching partially removed hemicelluloses, lignin, and amorphous fractions of cellulose. This led to the gradually increasing crystallinity of the treated fiber. Peak height values were obtained by measuring the transmittance of the spectra through FTIR analysis. Different physical and chemical properties of the extracted corn stalk fibers indicated that it can be used for making biodegradable composite materials.

Long-Term In Vitro Assessment of Biodegradable Radiopaque Composites for Fiducial Marker Fabrication.

Biodegradable polymer-based composite materials may be successfully utilised to fabricate fiducial markers (FMs), which are intended to precisely label tumour margins during image-guided surgery or radiotherapy. However, due to matrix degradability, the stability of the functional properties of FMs depends on the chosen polymer. Thus, this study aimed to investigate novel radiopaque composites which varied in the polymeric matrix-polycaprolactone (PCL), poly(L-lactide-co-caprolactone) (P[LAcoCL]) with two molar ratios (70:30 and 85:15), and poly(L-lactide-co-glycolide) (with molar ratio 82:18). The radiopaque component of the materials was a mixture of barium sulphate and hydroxyapatite. The changes in water contact angle, stiffness, and radiopacity occurring during the 24-week-long degradation experiment were examined for the first time. This study comprehensively analyses the microstructural causes of composites behaviour within degradation experiments using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permitted chromatography (GPC), and scanning electron microscopy (SEM). The obtained results suggest that the utilized biodegradable matrix plays an essential role in radiopaque composite properties and stability thereof. This long-term in vitro assessment enabled a comparison of the materials and aided in choosing the most favourable composite for FMs' fabrication.

Biodegradable composite material based on the starch-g-vinyl acetate copolymer

A native potato starch was modififi ed with vinyl acetate by graft polymerization in alkaline medium with pH 10 in the mode of temperature change from 70 to 80°C for 4 hours. The initiator of the process was ammonium persulfate (NH4)2S2O8. The conversion of vinyl acetate was 91,5%. The chemical structure of graft copolymer (Starch:Vinyl acetate) was confifi rmed by IR-spectroscopy. Composite materials of modififi ed starch and triethyl citrate with tensile strength of 24 MPa were obtained. Under natural environmental conditions, materials undergo biodegradation of 96% in 28 days.

Investigations on mechanical properties of wood composite for sustainable manufacturing

The additive manufacturing technique is foreseen to be the future of the manufacturing industries as it reduces material wastage and enables the machining of intricate shapes. Likewise, the unavailability of skilled laborers has drastically affected the engineering sector. Similarly, the high initial cost and biodegradability issues with the currently seen thermosetting polymer-based 3D printers limit their usage over the long run. Therefore, it is necessary to find better environment friendly alternatives that are renewable and sustainable. This paper proposes a wood powder-binder composite material for potential use in additive manufacturing systems and the preliminary results are presented. A study on the various mechanical properties of the prepared biodegradable wood powder-binder composite material is carried out. This methodology finds application in pattern making and prototyping.

Study of Progress on Nanocrystalline Cellulose and Natural Fiber Reinforcement Biocomposites

Cellulosic biomass hydrolysis yields a nanoscale substance known as nanocrystalline cellulose (NCC). Gel, liquid, or powder is adaptable to a variety of uses. Nanocrystalline cellulose has unique renewability, biodegradability, and mechanical and physicochemical qualities, and abundance boosts the material’s mechanical strength by many orders of magnitude when introduced into the material matrix (polymer, ceramic, or metal). Nanocrystalline cellulose is not related with any serious environmental issues because it is a natural substance. The progress of this biomaterial as a green and renewable biomaterial for the fabrication of lightweight and biodegradable composite materials gives further impetus. The current aim of nanocrystalline cellulose research is to optimise nanocrystalline cellulose characteristics for dispersion in hydrophilic and hydrophilic media. To assess the nanocrystalline cellulose reinforcing, antibacterial, stability, hydrophilicity, and biodegradability, imaging methods and protocols in complicated matrices will need to be developed. This review includes a discussion on nanocrystalline cellulose biocomposites.

Mechanical Properties, Critical Length, and Interfacial Strength of Seven-Islands-Sedge Fibers (Cyperus malaccensis) for Possible Epoxy Matrix Reinforcement

The growing concern about the limitation of non-renewable resources has brought a focus on the development of environmentally sustainable and biodegradable composite materials. In this context, a trend in the development of natural fibers used as a reinforcement in composites is ever-increasing. In this work, for the first-time, fibers extracted from the seven-islands-sedge plant (Cyperus malaccensis) have been characterized by X-ray diffraction (XRD) to calculate the crystallinity index and the microfibrillar angle (MFA). Also, an evaluation of the ultimate tensile strength by diameter intervals has been investigated and statistically analyzed by both the Weibull method and the analysis of variance (ANOVA). Moreover, the maximum deformation and tensile modulus have been found from the data acquired. Pullout tests have been conducted to investigate the critical length and interfacial strength when sedge fibers, are incorporated into epoxy resin matrix. Microstructure analysis by scanning electron microscopy (SEM) was performed to observe the mechanism responsible for causing rupture of the fiber as well as the effective fiber interfacial adhesion to the epoxy matrix.

Nanomaterial in Food Packaging: A Comprehensive Review

Food packaging industry is going through various scientific evolutions as per the preferences of the consumers along with the consumer trends. Current trends focus on not only protecting the food intelligently but also making it visually appealing to the consumer. In recent years, considerable attention is been given to replace nonbiodegradable materials with ecofriendly biodegradable composite material. Nanotechnology is flourishing and has proven to be a great incorporation to the packaging industry, as it can also overcome the drawbacks of the existing methods. Various nanomaterials have been explored and tested for manufacturing of packaging materials. In the present review, we discussed on current trends in food packaging and their drawbacks with respect to over consumption of plastic and how sustainable packaging is being implemented. Furthermore, nanotechnology is becoming a promising and widely used potential in food packaging industry along with nanomaterials currently being used such as zinc nanoparticles, polymer clay nanoparticles, and silver nanoparticles in food packaging. This information will broaden our current understanding on potential and problems associated with nanotechnology in food packaging.

Synthesis of Biocompatible Composite Material Based on Cryogels of Polyvinyl Alcohol and Calcium Phosphates.

At the moment, the field of biomedical materials science is actively developing, which aims at creating new functional materials. A developing direction in biomedical materials science is that towards the treatment of diseases associated with bone tissue disorders, using biodegradable composite materials based on polymer and calcium phosphate materials. We developed a material based on polyvinyl alcohol cryogel, mineralized with calcium phosphate. A material based on cryogel of polyvinyl alcohol mineralized with calcium phosphate was developed. The composites were obtained by the method of cyclic freezing–thawing, and the synthesis of calcium phosphates was carried out in situ with heating, stirring, and exposure to microwave radiation. The phase composition, as well as the composition of functional groups, was determined by IR spectroscopy and X-ray phase analysis. Monocytes isolated from human blood showed higher viability compared to the controls.

Biological Application of Novel Biodegradable Cellulose Composite as a Hemostatic Material.

Degradable hemostatic materials have unique advantages in reducing the amount of bleeding, shortening the surgical operation time, and improving patient prognosis. However, none of the current hemostatic materials are ideal and have disadvantages. Therefore, a novel biodegradable cellulose-based composite hemostatic material was prepared by crosslinking sodium carboxymethyl cellulose (CCNa) and hydroxyethyl cellulose (HEC), following an improved vacuum freeze-drying method. The resulting cellulose composite material was neutral in pH and spongy with a density of 0.042 g/cm3, a porosity of 77.68%, and an average pore size of 13.45 μm. The composite's compressive and tensile strengths were 0.1 MPa and 15.2 MPa, respectively. Under in vitro conditions, the composites were degraded gradually through petite molecule stripping and dissolution, reaching 96.8% after 14 days and 100% degradation rate at 21 days. When implanted into rats, the degradation rate of the composite was slightly faster, reaching 99.7% in 14 days and 100% in 21 days. Histology showed a stable inflammatory response and no evidence of cell degeneration, necrosis, or abnormal hyperplasia in the tissues around the embedded material, indicating good biocompatibility. In the hemorrhagic liver model, the time to hemostasis and the total blood loss in the cellulose composite group was significantly lower than in the medical gauze group and the blank control group (P < 0.05). These data indicate that the novel cellulose composite is a promising implantable hemostatic material in clinical settings.

Comprehensive characterization of raw and treated pineapple leaf fiber/polylactic acid green composites manufactured by 3D printing technique

AbstractThe aim of this study is to develop a completely sustainable, biodegradable, eco‐friendly and green composite material for packaging of food and medical products by an additive manufacturing technique such as 3D printing. This report presents the mechanical, crystalline, chemical bonding and thermal characteristics of a novel pineapple leaf fiber (PALF) reinforcing polylactic acid (PLA) green composite manufactured by 3D printing technique. Both powdered raw and alkali‐treated PALFs were respectively mixed with PLA and extruded as filaments for 3D printing into composite test specimens. The characterization study reveals that the 3D printed composite with 3 wt% (alkali‐treated) PALF reinforcement exhibited maximum tensile and flexural characteristics. The density of the 3D printed composite specimens increased with increase in wt% of PALF. On the other hand, the 3D printed composite specimens blended with raw PALF showed enhanced elongation at break compared to alkali‐treated PALF reinforced composite specimens. The microstructural images of the 3D printed composite specimens confirms the existence of impurities, voids and fiber degradation phenomenon. The Fourier transform infrared spectra revealed the chemical bonding nature of the 3D printed composite specimens. The X‐Ray diffraction was used to calculate the crystalline size and crystallinity index. Thermogravimetric analysis reveals that the 3D printed composite specimen possessed adequate thermal stability for use in packaging applications.

Accelerable Self-Sintering of Solvent-Free Molybdenum/Wax Biodegradable Composites for Multimodally Transient Electronics.

Biodegradable conductive composites are key materials or components for printable transient electronics that can be fabricated in a low-cost and high-efficiency manner, thereby boosting their wide applications in biomedical engineering, hardware security, and environmental-friendly electronics. Continuous efforts in this area still lie in the development of strategies for highly conductive, safe, and reliable biodegradable conductive composite materials and devices. This paper introduces molybdenum/wax composites for multimodally printable transient electronics in which multiple transience modes including dissolution-induced degradation and thermally triggered degradation are available. Systematic experiments demonstrate several advantages and unique properties of this material system, including solvent-free fabrication, self-sintering behavior, and long-term and high conductivity via accelerable self-sintering treatment and rehealing capabilities. Notably, the immersion of molybdenum/wax composites in phosphate buffer solution can provide both positive effects (accelerated self-sintering-dominated) and negative effects (degradation-dominated) on their electrical conductivities. Mechanism analyses reveal the basis for balancing the degradation and accelerated self-sintering processes. The presented demonstrations foreshadow opportunities of the developed molybdenum/wax composites in rehealable electronics, on-demand smart transient electronics with multiple transience modes, and many other related unusual applications.

Viscoelastic Characterization and Degradation Stability Investigation of Poly(butylene-adipate-co-terephthalate) – Calcium-Phosphate Glass Composites

In this work new biodegradable composite materials based on poly(butylene-adipate-co-terephthalate) (PBAT) reinforced with water-soluble calcium-phosphate glass (CPG) microparticles at different filler concentration (0, 4, 10, 20 and 40 wt%) were characterized by dynamic-mechanical analysis (DMA), aging and fragmentation tests. DMA results showed increasing storage modulus (E′) values with the filler content, without a significant modification of the glass transition temperature (Tg), translating in a reinforcing effect of the filler particles with good interphase adhesion. The creep compliance decreased with the increase of the CPG content, confirming a greater resistance of the composites to deformation under constant stress. The stability to weathering agents and the degree of fragmentation in laboratory-scale composting conditions were also tested, obtaining a higher sensitivity to degradation of the PBAT-based composites with the increase of CPG content. Overall, the addition of CPG particles in a PBAT matrix produced stiffer composites, with modulation of the properties based on the filler content, enhancing at the same time their degradation rate, making them a promising and more sustainable alternative to traditional polymers.Graphical

Analysis of Drilling of Coir Fiber-Reinforced Polyester Composites Using Multifaceted Drill Bit

Composite materials are continuously replacing the conventional materials and alloys owing to their weight reduction. Biodegradable fiber-reinforced composite materials are one of the prime attractions to the researcher due to their easy availability and low cost. During drilling of these Natural Fiber Reinforced Plastic composites (NFRP), delamination and surface roughness are the problems encountered, which are to be minimized to get better output by adopting different cutting conditions and tools. This work aims at the drilling of naturally available coir fiber-reinforced composite materials by using a multifaceted drill bit. Material thickness, spindle speed, feed rate, and multifaceted bit diameter are input against the output delamination. After modeling of the output result, a sensitivity analysis tool is introduced to rate the input factor to minimize delamination. SEM images are used to analyze the fracture morphology.