Bio-based Composites Research Articles

A strong hydrogen bond bridging interface based on tannic acid for improving the performance of high-filled bamboo fibers/poly (butylene succinate-co-butylene adipate) (PBSA)biocomposites

Natural plant fiber-reinforced bio-based polymer composites are widely attracting attention because of their economical, readily available, low carbon, and biodegradable, and showing promise in gradually replacing petroleum-based composites. Nevertheless, the fragile interfacial bonding between fiber and substrate hinders the progression of low-cost and abundant sustainable high-performance biocomposites. In this paper, a novel high-performance sustainable biocomposite was built by introducing a high density strong hydrogen-bonded bridging interface based on tannic acid (TA) between bamboo fibers (BFs) and PBSA. Through comprehensive analysis, this strategy endowed the biocomposites with better mechanical properties, thermal stability, dynamic thermo-mechanical properties and water resistance. The optimum performance of the composites was achieved when the TA concentration was 2 g/L. Tensile strength as well as modulus, flexural strength as well as modulus, and impact strength improved by 22 %, 10 %, 15 %, 35 %, and 25 % respectively. Additionally, the initial degradation temperature(Tonset) and maximum degradation temperature(Tmax) increased by 12.07 °C and 14.8 °C respectively. The maximum storage modulus(E'), room temperature E', and loss modulus(E")elevated by 199 %, 75 %, and 181 % respectively. Moreover, the water absorption rate decreased by 59 %. The strong hydrogen-bonded bridging interface serves as a novel model and theory for biocomposite interface engineering. At the same time, it offers a promising future for the development of high performance sustainable biocomposites with low cost and abundant biomass resources and contributes to their wide application in aerospace, automotive, biomedical and other field.

Mechanical recycling of biobased polyethylene-agave fiber composites

Biobased polymers have emerged as a promising alternative to petroleum-based polymers in terms of lower environmental impact. However, to improve their carbon footprint, it is important to study strategies, such as recycling, extending the useful life of these biopolymers, and mitigate their higher costs compared to petroleum-based polymers. Adding agro-industrial wastes as fillers or reinforcements is another option to reduce the cost and increase the biobased content to produce composites. This study aimed to evaluate the addition of agave fibers to biobased linear low-density polyethylene (bio-LLDPE) and their effect on its reprocessing by extrusion, i.e., close-loop mechanical recycling. The results revealed that it was possible to reprocess the bio-LLDPE alone as limited changes in their physical properties were observed up to 34 cycles. However, for the composites, the viscosity changed in the first eight cycles mainly due to fiber break-up (lower aspect ratio). The dimensions of the agave fibers are modified by reprocessing. In the initial 8 cycles, there is a notable decrease in fiber dimensions, affecting the tensile, flexural, and impact properties of the composites. The water uptake was found to decrease with each cycle due to better fiber dispersion and the reduction of interfacial voids/defects. Nevertheless, the color of the bio-LLDPE and its composites showed significant changes by reprocessing, which is associated with thermal and oxidation degradation. Despite minor property losses, the study reveals that bio-LLDPE/agave fiber composites exhibit a commendable level of sustainability. This characteristic enables their extended reuse and reprocessing over a prolonged duration.

Influence of bio-based kenaf polymer composites on mechanical and acoustic properties for futuristic applications: An initiative towards net-zero carbon emissions

In the pursuit of net-zero carbon emissions, the development of sustainable materials like kenaf fiber composites is pivotal. This innovative approach, which harnesses eco-friendly properties and enhances material performance, holds promise in reducing carbon footprints across diverse industries. As ecological sustainability awareness continues to rise, there is a growing imperative to embrace biodegradable, lightweight, and recyclable materials to address existing limitations in conventional materials. Kenaf fiber, with its unique electromagnetic, acoustic, mechanical, and physical properties, presents a compelling solution. The production process involves impregnating kenaf fiber with bio-based materials, utilizing nanofillers of nickel (Ni), bamboo charcoal (BC), and carbon black (CB), which are blended with epoxy resin through magnetic agitation to ensure homogeneous dispersion. This resulting composite is fortified between two layers of kenaf fiber mats, creating a robust sandwich structure. Employing response surface methodology (RSM) and the central composite design (CCD), the study calculates the optimal weight percentages of nanofillers in various test specimens. Mechanical and acoustic property testing, conducted using appropriate equipment, reveals that a combination of 15 wt% BC, 9 wt% Ni, and 6 wt% CB exhibits the highest tensile strength at 42 MPa, while the blend of 10 wt% BC, 6 wt% Ni, and 4 wt% CB achieves a maximum noise reduction coefficient (NRC) of 0.524. These impressive findings underscore the potential of this suggested material as a superior substitute for conventional materials, further aligning it with the imperative for eco-conscious and sustainable solutions.

Study of the dielectric and chemical properties of cellulose bio-based composites

Injection molded cellulose bio-based composites have been effectively manufactured using cellulose acetate (CA), environmentally friendly triethyl citrate (TEC) plasticizer, and cellulosic fibers. This study investigated the surface chemistry, the thermal stability, and the dielectric properties of CA biopolymer and its bio-based composites. DSC result of plasticized cellulose acetate (PCA) showed that the glass transition temperature decreased from 191°C to 101°C and the melting temperature from 224°C to about 140°C after plasticization, which improves the processing of the biopolymer Fourier Transform Infrared (FTIR) spectroscopy was used to determine the chemical properties of the raw materials and the bio-based composites. The results showed a good plasticization effect of TEC plasticizer by the presence of ester bonds at 1734 cm−1 in PCA spectra. Chemical interactions between hydroxyl groups of the different components were also observed in the 3200–3600 cm−1 region. Dielectric analysis at different frequencies of cellulose bio-based composites showed enhanced dielectric properties compared to pure PCA polymer. Composites with 50 wt% cellulose fibers had values of ε' and tan δ of about 4 and 0.13 at 1 MHz, respectively. These properties decreased as the frequency increased from 1 MHz to 3 GHz, reaching values of 2.8 and 0.04, respectively. The increase in temperature from the frozen state induced an increase in the dielectric properties and showed a relaxation process that shifted to higher temperatures at higher frequencies.

Impact Characteristics and Repair Approaches of Distinct Bio-Based Matrix Composites: A Comparative Analysis

Increasing global concerns regarding environmental issues have driven significant advancements in the development of bio-based fiber reinforced polymer composites. Despite extensive research on bio-composites, there remains a noticeable gap in studies specifically addressing the challenges of repairing bio-composites for circular economy adoption. Traditional repair techniques for impacted composites, such as patching or scarf methods, are not only time-consuming but also require highly skilled personnel. This paper aims to highlight cost-effective repair strategies for the restoration of damaged composites, featuring flax fiber as the primary reinforcement material and distinct matrix systems, namely bio-based epoxy and bio-based vitrimer matrix. Glass fiber was used as a secondary material to validate the bio-based vitrimer matrix. The damage caused specifically by low impact is detrimental to the structural integrity of the composites. Therefore, the impact resistance of the two composite materials is evaluated using instrumented drop tower tests at various energy levels, while thermography observations are employed to assess damage evolution. Two distinct repair approaches were studied: the resin infiltration repair method, employing bio-based epoxy, and the reconsolidation (self-healing) repair method, utilizing the bio-based vitrimer matrix. The efficiency of these repair methods was assessed through active thermography and compression after impact tests. The repair outcomes demonstrate successful restoration and the maintenance of ultimate strength at an efficiency of 90% for the re-infiltration repair method and 92% for the reconsolidation repair method.

Biomass waste lotus shell-based shape-stabilized phase change composites with improved thermal conductivity for thermal management

Lotus shells represent an underutilized renewable resource with desirable porous architecture for producing bio-based phase change composites (PCMs). This research endeavors to fabricate a series of shape-stable phase change composites (SSPCCs) based on n-docosane (ND) and waste lotus shells to enhance heat utilization, solar photothermal energy conversion, and promote environmental protection. Both carbonization and activation processes play a critical role in the formation of desired pore structures. The carbonized lotus shells (CLS) and activated lotus shells (ALS) exhibit superior specific surface areas, reaching 147.70 m2/g for CLS and 1652.35 m2/g for ALS. Notably, the composite of ND integrated with ALS (ND/ALS) exhibits satisfactory latent heat storage of 93.68 J/g, excellent leakage prevention, and exceptional thermal cycle stability. Subsequently, the ND/ALS displays a significantly enhanced thermal conductivity of 0.482 W/(m·K) with an appreciable increment of 189% compared to ND. Furthermore, the obtained SSPCCs present good chemical compatibility, satisfactory thermochemical stability, and outstanding thermal management capability. In conclusion, the novel waste lotus shell-derived SSPCCs exhibit extensive potential for thermal management, such as heat recovery, solar energy conversion, and temperature regulation. This research not only introduces a promising avenue for enhancing sustainable materials in energy storage and conversion but also pioneers an innovative recycling strategy for waste lotus shells, thereby contributing to both environmental sustainability and efficient resource utilization.

Sandwich structures of aluminium skins and egg-box-shaped cores made with biobased foam and composites

Sandwich panels composed of aluminium skins and egg-box-shaped cores made with natural fibre composites are tested in three-point bending and evaluated statistically and through failure analysis. The corrugated cores are assessed with filled bio-based foam. In order to produce these sandwich panels, preliminary investigations on natural fibre composites, and their use as egg-box-shaped structures are conducted. A full factorial design is performed to assess the effects of fibre reinforcement (sisal or coir) and polymer matrix types (epoxy or castor oil) on the physical-mechanical properties of flat composite laminates. These composites are also used to manufacture the egg-box shaped structures in different sizes, which are characterized under compression testing. A new analytical approach called RJS Method is used to determine the flexural and shear modulus of the proposed sandwich panels and estimate the shear contribution. The results reveal that flat laminated composites and their corresponding egg-box shaped cores, composed of sisal fibres and epoxy polymer, achieve higher absolute and specific mechanical properties. The corrugated core also leads to sandwich panels with higher mechanical properties, increasing the skin and core shear stresses by up to 60 and 76%, respectively, compared to the coir fibre castor-oil cores. The failure modes of the sandwich panels are limited to the core and are chronologically established through foam tearing, foam-egg-box shaped composite debonding, and final egg-box cell-wall flattening. The findings demonstrate that the sandwich panel based on egg-box shaped core made from natural resources is feasible for scaling up in different structural applications.

Bio-based aerogel composites of coconut pith-derived carbon and chitosan for efficient anionic dye-polluted water treatment

Abstract Biomass-based aerogels are of interest due to their abundant precursors, ease of functionalization, eco-friendliness, low cost, and effectiveness in dye-contaminated water treatment. Coconut pith (CP) known as a by-product after coconut processing is a sponge-like and lightweight material discarded in large volumes. For the first time, carbon micro-particles resulting from two-step treatment and pyrolysis of CP have been successfully incorporated with chitosan to produce aerogel composites by high-speed homogenization and freeze-drying. After pretreatment, holocellulose content and crystallinity index of the recovered CP pulp are respectively 75.4 and 58.6 % along with a solid recovery rate of 27.5 %. Characteristic properties of the aerogel composites are featured by their density as low as 15.23–28.17 mg/cm3, remarkably high porosity of 98.17–99.05 %, and Young’s modulus of 1.64–12.23 kPa. Synergistic effects of the porous network, electrostatic interactions between both amine groups in chitosan and carbon surface with methyl orange (MO) cause the as-fabricated aerogel composites to achieve an extremely high adsorption capacity of 454.13 mg/g and removal efficiency of 92.32 % at initial MO concentration of 500 mg/L. Therefore, the CP-derived carbon/chitosan aerogel composites synthesized from a feasible procedure exhibit their great potential in enhancing the value of coconut waste and dealing with dye-contaminated water pollution by simple and economical adsorption.

Card-bisphenol based bio-silica reinforced poly(urethane-co-benzoxazine) foam for an electrical insulation

Agricultural waste by-products such as cashew nut shell liquid and rice husk ash were utilized for the syntheses of card-bisphenol (C) and precipitated bio-silica (S), respectively. A hydroxyl terminated card-bisphenol based benzoxazine resin (CHB) was synthesized and then converted it into soft-foam namely benzoxazine-co-urethane pre-polymer (CHB-UF) by polymerizing with hexamethylene diisocyanate (HMDI) in the absence of any catalysts or foaming agents. Subsequent thermal ring opening polymerization of CHB-UF at 200 °C provides poly(benzoxazine-co-urethane) hard-foam (PCHB-UF) with little shrinkage. Similarly, different weight ratios of precipitated bio-silica (0–15 wt%) reinforced bio-based PCHB-UF hard-foam composites (PCHB-UFS) were prepared to utilize them for high-k dielectrics and hydrophobic applications. The foam microstructure was ascertained through the field emission scanning electron microscopy (FE-SEM). The reinforcement of bio-silica into the CHB-UF foam increases the value of dielectric constant according to the increase in weight percentage concentration, which might be due to the reduction in volume of voids. The neat PCHB-UF possesses the value of dielectric constant of 7.04 with lower value of dielectric loss of 0.01. Similarly, the values of dielectric constant and dielectric loss of 15 wt% bio-silica reinforced composites (PCHB-UFS15) are 10.1 and 0.08 respectively. The PCHB-UFS15 has shown hydrophobic nature with the value of water contact angle of 135°. Data obtained from different studies suggest that the bio-foam composites obtained from sustainable sources can be considered as an efficient dielectric materials used for electronics insulation.

Avocado seed starch utilized in eco-friendly, UV-blocking, and high-barrier polylactic acid (PLA) biocomposites for active food packaging applications

Efficient and effective use of biopolymers, such as starch, has increasingly prompted interest due to the current environmental challenges. However, starch-based composites still show poor ductility along with water and oxygen permeability, which may not meet the requirements for food packaging standards. In this study, modified starch (m-St), isolated from the avocado seed and synthesized with tert-butyl acetoacetate (t-BAA), was embedded into polylactic acid (PLA) to design new eco-friendly composites. The developed biocomposites were found to exhibit high performance with outstanding mechanical properties in conjunction with remarkable light, water vapor, and oxygen blocking features for food packaging applications. PLA/m-St(1:6) 20 wt% composites showed a dramatic increase in elongation at break (EB%) from 3.35 to 27.80 % (about 730 % enhancement) and exhibited remarkable UV-blocking performance from 16.21 to 83.86 % for UVB, relative to pure PLA. Equally importantly, these biocomposites revealed significant improvement in oxygen and water vapor barrier performance by reducing their values from 1331 to 32.9 cc m−2 day−1 (indicating a remarkable reduction of 97.53 %) and 61.9 to 28 g m−2 day−1, respectively. This study can show the great potential of extracting starch from biowaste resources and transforming it into sustainable bio-based composites as a promising solution for food packaging applications.

Environmental Durability of Bio-Based and Synthetic Thermoplastic Composites in Large-Format Additive Manufacturing.

This research investigates the durability of large-format 3D-printed thermoplastic composite material systems under environmental exposure conditions of moisture and freeze-thaw. Durability was evaluated for two bio-based composite material systems, namely wood-fiber-reinforced semi-crystalline polylactic acid (WF/PLA) and wood-fiber-reinforced amorphous polylactic acid (WF/aPLA), and one conventionally used synthetic material system, namely short-carbon-fiber-reinforced acrylonitrile butadiene styrene (CF/ABS). The moisture absorption, coefficient of moisture expansion, and reduction of relevant mechanical properties-flexural strength and flexural modulus-after accelerated exposure were experimentally characterized. The results showed that the large-format 3D-printed parts made from bio-based thermoplastic polymer composites, compared to conventional polymer composites, were more susceptible to moisture and freeze-thaw exposure, with higher moisture absorption and greater reductions in mechanical properties.

Life cycle assessment of sugarcane bagasse based natural composites prepared via vacuum bagging technique

The demand for lightweight materials has been constantly mounting in aerospace and other structural applications with focus towards sustainable and green engineering. In aerospace applications, various industrial regulations have stepped towards carbon composites replacement owing to its inability to repair and recycle which has envisaged to bio-based composites depending on the manufacturing processes. This paper focuses on life cycle analysis of bagasse based biocomposites which are predominant by-product from sugarcanes. The sugarcane bagasse biocomposites were prepared through vacuum bagging technique and their emission and energy consumptions were analyzed. The sugarcane bagasse biocomposites showcased overall energy consumption of ∼178 MJ and ∼30 kgCO2Eq. global warming potential (GWP) with chemical treatment, pesticides, and vacuum bagging as major processes. The energy consumption of biocomposites was ∼5 times less than carbon composites procured via same route illustrating sugarcane bagasse as more environmentally friendly but requiring additional research to understand the transition towards bio-based materials.

The effect of triglycerol diacrylate on the printability and properties of UV curable, bio-based nanohydroxyapatite composites

3D printable biopolymer nanocomposites composed of hydroxyapatite nanoparticles and functionalized plant-based monomers demonstrate potential as sustainable and structural biomaterials. To increase this potential, their printability and performance must be improved. For extrusion-based 3D printing, such as Direct Ink Writing (DIW), printability is important for print fidelity. In this work, triglycerol diacrylate (TGDA) was added to an acrylated epoxidized soybean oil:polyethylene glycol diacrylate resin to increase hydrogen bonding. Greater hydrogen bonding was hypothesized to improve printability by increasing the ink's shear yield strength, and therefore shape holding after deposition. The effects of this additive on material and mechanical properties were quantified. Increased hydrogen bonding due to TGDA content increased the ink's shear yield stress and viscosity by 916% and 27.6%, respectively. This resulted in improved printability, with best performance at 3 vol% TGDA. This composition achieved an ultimate tensile strength (UTS) of 32.4 ± 2.1 MPa and elastic modulus of 1.15 ± 0.21 GPa. These were increased from the 0 vol% TGDA composite, which had an UTS of 24.8 ± 1.8 MPa and a modulus of 0.88 ± 0.06 GPa. This study demonstrates the development of bio-based additive manufacturing feedstocks for potential uses in sustainable manufacturing, rapid prototyping, and biomaterial applications.

Effects of Temperature and Layer Thickness on the Static and Dynamic Behaviors of Biocomposite Materials with Interleaved Viscoelastic Layers

This study investigated the influence of temperature variations on the mechanical and dynamic behaviors of biobased composites incorporating a passive control layer. These composites, which include an external layer made up of Flax/polylactic acid (PLA) and an internal layer of rubber, were manufactured using 3D printing technique. To better understand their mechanical characteristics, bending tests were carried out on samples of Flax/PLA with and without a rubber coating at temperatures ranging from [Formula: see text]C to [Formula: see text]C. To evaluate the bending response of the materials under several temperatures settings, three-point bending tests were also conducted on the materials with different viscoelastic layer thicknesses. Additionally, resonance vibration studies were carried out at various temperatures to explore dynamic characteristics like frequencies and damping factors. The analysis of the data revealed the consequences of incorporating a functional rubber layer under diverse circumstances. The results demonstrated that increasing temperatures negatively impacts the mechanical and dynamic characteristics degradation of the composite with the viscoelastic layer. The main objective of this work is that under various thermal settings, passive control layers in biocomposites can display modified mechanical and dynamic behaviors. This understanding of how these biobased composites perform in different environments offers significant context for their possible applications.

Bio-based composites from bagasse using carbohydrate enriched cross-bonding mechanism: A formaldehyde-free approach

In this study, cross-bonded self-binding and bone glue-bonded particleboards were manufactured from sugarcane (Saccharum officinarum L.) bagasse with different pre-treatments of particles. Six types of panels were manufactured from bagasse particles with and without bone glue. The physical, mechanical, and thermal properties of the panels were examined according to the standards. Fourier Transform Infrared (FTIR) spectroscopy and thermogravimetric analysis (TG) were performed to investigate the changes in the chemical bonds and thermal stability of the fabricated composites, respectively. It was found that cross-bonded bagasse self-binding (TC) and bone glue-bonded (T3) panels fabricated from non-boiled bagasse particles showed higher physical and mechanical properties compared to the other types of panels. Non-boiled bagasse particles with bone glue panels showed the highest mechanical properties, i.e., modulus of rupture (MOR = 26.22 MPa), modulus of elasticity (MOE = 4302 MPa), tensile strength = 8.35 MPa, and hardness = 1.72 MPa. TC and T3 panels also showed higher thermal stability compared to the other types of panels. A new peak at 3331–3334 cm−1 for the NH stretching vibration in the FTIR analysis represents the presence of bone glue in the cross-bonded particleboards. Thus, this research advances the production of formaldehyde-free bagasse particleboard, introducing the cross-bonding technique and sustainable bone glue.

Green, recyclable and high latent heat form-stable phase change composites supported by cellulose nanofibers for thermal energy management

Efficiently addressing the challenge of leakage is crucial in the advancement of solid-liquid phase change thermal storage composite materials; however, numerous existing preparation methods often entail complexity and high energy consumption. Herein, a straightforward blending approach was adopted to fabricate stable phase change nanocomposites capitalizing on the interaction between TEMPO-oxidized cellulose nanofibers (TOCNF) and polyethylene glycol (PEG) molecules. By adjusting the ratio of TOCNF to PEG and the molecular weights of PEG, TOCNF/PEG phase change composites (TPCC) with customizable phase transition temperature (40.3–59.1 °C) and high phase transition latent heat (126.3–172.1 J/g) were obtained. The TPCC of high-loaded PEG (80–95 wt%) ensured a leakage rate of less than 1.7 wt% after 100 heating-cooling cycles. Moreover, TPCC exhibits excellent optical properties with a transmittance of over 90 % at room temperature and up to 96 % after heating. The thermal response analysis of TPCC demonstrates exceptional thermal-induced flexibility and good thermal stability, as well as recyclability and reshaping ability. This study may inspire others to design bio-based phase change composites with potential applications in thermal energy storage and management of smart-energy buildings, photothermal response devices, and waste heat-generating electronics.

Experimental investigation on duration of load effect of novel inorganic-bonded bamboo composite under flexural load

Conventional engineered wood and bamboo materials commonly require organic adhesives for adequate bonding. As an alternative solution in bio-based composites, a novel bamboo-based composite prepared with a magnesium-based inorganic adhesive was proposed herein, which is named as “inorganic-bonded bamboo composite” and abbreviated as InorgBam. This study investigates the duration of load (DOL) effect on InorgBam beams under long-term flexural load. The percentile matching method was used to obtain the short-term strengths matched to the long-term specimens, and the strength reduction of the long-term specimens was obtained. The DOL result were calibrated using the DOL empirical formulas and DOL damage models, including Gerhards, Foschi and Yao, and Nielsen models. The impact of the selected cumulative probability functions of short-term strength on the DOL analysis has also been discussed. Results illustrated that the strength reduction in the InorgBam was less than the prediction of Madison curve. The value of DOL coefficient determined with Foschi and Yao model was closest to that derived from the empirical fitted formula. The DOL effect of the InorgBam beams was significantly smaller than that of conventional engineered wood beams, which is beneficial for determining the design strength value of InorgBam material.

Mechanical and morphological analysis of cellulose extracted from sisal fibers and their effect on bio-based composites mechanical properties

This study aims to investigate the viability of untreated sisal fibers (N.F.), NaOH-treated sisal fibers (NaOH.F.) and cellulose extracted from sisal (CELL.F.) as an alternative to synthetic materials to produce biocomposites. The main objective was to conduct an in-depth study of the properties of these fibers whose aim is to limit matrix/fiber slippage and improve adhesion by modifying reinforcement surfaces, and to improve the efficiency of sisal fibers as reinforcements for composite materials using various analytical techniques including Fourier transform infrared spectroscopy, scanning electron microscopy, x-ray diffraction, and thermogravimetric analysis. In addition, the study aimed to produce a composite material by reinforcing plaster with the aforementioned fibers and then compare the mechanical and physical properties of the resulting material. The results showed that cellulose fibers exhibited higher mechanical strength and better compatibility with the plaster-matrix compared to sisal fibers by an increse of 324% in their tensil strength compared to natural sial fibers. In particular, the flexural strength showed a significant increase of 35% in the cellulose fiber reinforced composite. The reinforced composite material exhibited improved properties such as better flexural strength, increased absorption by 12.8% and descres the density by 21.3%, highlighting the promising prospects of cellulose fibers in advancing biocomposite technology.

Preparing strong, tough, and high-barrier biobased polyester composites by regulating interfaces of carbon nanotubes

Carbon nanotubes (CNTs) have been regarded as ideal functional fillers for enhancing superior mechanical properties of polymer composites. However, the performances of CNTs-based composites are well below the theoretical values, due to the poor dispersion of inert CNTs and weak interfacial interaction with the polymer matrix. Herein, “hydrothermal and in-situ growth” approach is induced to synthesize multiscale TiO2@CNTs functional fillers. Such the TiO2@CNTs show excellent dispersibility and strong interfacial bonding with matrix. The biobased TiO2@CNTs/poly (ethylene furandicarboxylate) (TCP) composite films are prepared via loading a small amount (0.05–0.2 wt%) of TiO2@CNTs. When the mass content of fillers is 0.2 wt%, TCP composite film exhibits the optimal of strength (80 MPa), Young's modulus (4.12 GPa), and toughness (1.2 MJ/m3). Moreover, the presence of TiO2 nanoparticles endow the films with excellent oxygen barrier and UV-shielding properties. We believe these composite films promise a spread application potential in high-performance food packing materials.

Construction and mechanism analysis of flame-retardant, energy-storage and transparent bio-based composites based on natural cellulose template

With the proposal of sustainable development strategy, bio-based energy storage transparent wood (TW) has shown broad application value in green buildings, cold chain transportation, and optoelectronic device fields. However, its application in most fields is limited due to its own flammability. In this study, epoxy resin, triethyl phosphate (TEP) and polyethylene glycol (PEG) were introduced into delignified balsa wood template by vacuum pressure impregnation, and bio-based TW/PEG/TEP integrating flame retardant, high strength and phase-change energy-storage performance was prepared. TW/PEG composites have no leakage during phase change process and their transparency is up to 95 %. Compared with TW/PEG, the shielding effect of char layer and the inhibition effect in condensed and gas phase significantly decrease the total heat release of TW/PEG/TEP. TW/PEG/TEP biocomposites still maintained a high enthalpy of phase change and a low peak melting temperature, which was conducive to its application around the area of low temperature phase change energy storage. In addition, the tensile strength of TW/PEG/TEP was nearly 4 times higher than that of DW, and its toughness was obviously enhanced. TW/PEG/TEP biocomposites conformed to the current concept of energy-saving and green development. It has the potential to replace traditional petrochemical-based materials and shows excellent application prospects in emerging fields.