Acrylated Epoxidized Soybean Oil Research Articles

Fully Bio-Based Polymer Composites: Preparation, Characterization, and LCD 3D Printing.

The present work aimed to prepare novel bio-based composites by adding fillers coming from agro-wastes to an acrylate epoxidized soybean oil (AESO) resin, using liquid crystal display (LCD) 3D printing. Different photocurable formulations were prepared by varying the reactive diluents, iso-bornyl methacrylate (IBOMA) and tetrahydrofurfuryl acrylate (THFA). Then, two fillers derived from different industrial wastes, corn (GTF) and wine (WPL-CF) by-products, were added to the AESO-based formulations to develop polymer composites with improved properties. The printability by LCD of the photocurable formulations was widely studied. Bio-based objects with different geometries were realized, showing printing accuracy, layer adhesion, and accurate details. The thermo-mechanical and mechanical properties of the 3D-printed composites were tested by TGA, DMA, and tensile tests. The results revealed that the agro-wastes' addition led to a remarkable increase in the elastic modulus, tensile strength, and glass transition temperature in the glassy state for the systems containing IBOMA and for flexible structures in the rubbery region for systems containing THFA. AESO-based polymers demonstrated tunable properties, varying from rigid to flexible, in the presence of different diluents and biofillers. This finding paves the way for the use of this kind of composite in applications, such as biomedical for the realization of prostheses.

Impact of chemical composition of soybean oil and vanillin-based photocross-linked polymers on parameters of electrochemical biosensors

Network properties on local free volume and biosensor parameters of polymers based on acrylated epoxidized soybean oil (AESO), a combination of AESO with vanillin dimethacrylate (VDM) in ratio 1:0.25 mol, and its combination with vanillin diacrylate (VDA) with the same molar ratio, used as laccase-holding matrixes for the construction of amperometric biosensors, were tested and compared. The formed polymer matrixes were investigated using Positron Annihilation Lifetime Spectroscopy (PALS) as bulk samples and applying electrochemical methods as sensor films. PALS results showed that the lifetime of the ortho-positronium component and corresponding intensity are almost similar for both polymers, indicating no significant difference from the point of view of their morphology. However, the cyclic voltammetric and chronoamperometric analysis demonstrated significant differences in the bioelecrodes’ operational parameters formed by the AESO:VDM polymer compared to AESO:VDA. The AESO:VDA-based bioelectodes were characterized with a twice higher affinity toward ABTS (KMapp = 0.158 ± 0.022 mM vs. 0.326 ± 0.043 mM). At the same time, their sensitivity was about twice less compared to AESO:VDM-based (902 A·M−1·m−2vs. 1608 A·M−1·m−2), and a start concentration of the linear frame was 7-folds higher (14 μM vs. 2 μM ABTS). It was shown early, that the operational parameters of amperometric biosensors are greatly dependent on morphological characteristics of polymer matrixes (e.g., crosslink density, cavities size, thermal expansion of free-volume hole, etc.). The matrix morphology affects on efficacity of physical diffusion of the substrate to the enzyme, and electroactive product toward the electrode, as well as provides a comfortable environment for the incorporated enzyme. Here, we describe the usage of polymer matrixes with the same morphological properties but different chemical compositions, analyzing the effect of chemical structure on the operational parameters of biosensors. Thus, it was demonstrated that the sensor operational parameters depend not only on the morphological properties of the polymer holding matrixes, providing enzyme fixation and substrate/product diffusion, but also on their chemical composition, which opens a possibility to adapt the biosensor characteristics according to the required needs of analysis.

In vitro evaluation of bone cell response to novel 3D-printable nanocomposite biomaterials for bone reconstruction.

Critically-sized segmental bone defects represent significant challenges requiring grafts for reconstruction. 3D-printed synthetic bone grafts are viable alternatives to structural allografts if engineered to provide appropriate mechanical performance and osteoblast/osteoclast cell responses. Novel 3D-printable nanocomposites containing acrylated epoxidized soybean oil (AESO) or methacrylated AESO (mAESO), polyethylene glycol diacrylate, and nanohydroxyapatite (nHA) were produced using masked stereolithography. The effects of volume fraction of nHA and methacrylation of AESO on interactions of differentiated MC3T3-E1 osteoblast (dMC3T3-OB) and differentiated RAW264.7 osteoclast cells with 3D-printed nanocomposites were evaluated in vitro and compared with a control biomaterial, hydroxyapatite (HA). Higher nHA content and methacrylation significantly improved the mechanical properties. All nanocomposites supported dMC3T3-OB cells' adhesion and proliferation. Higher amounts of nHA enhanced cell adhesion and proliferation. mAESO in the nanocomposites resulted in greater adhesion, proliferation, and activity at day 7 compared with AESO nanocomposites. Excellent osteoclast-like cells survival, defined actin rings, and large multinucleated cells were only observed on the high nHA fraction (30%) mAESO nanocomposite and the HA control. Thus, mAESO-based nanocomposites containing higher amounts of nHA have better interactions with osteoblast-like and osteoclast-like cells, comparable with HA controls, making them a potential future alternative graft material for bone defect repair.

Improving the 3D Printability and Mechanical Performance of Biorenewable Soybean Oil-Based Photocurable Resins.

The general requirement of replacing petroleum-derived plastics with renewable resources is particularly challenging for new technologies such as the additive manufacturing of photocurable resins. In this work, the influence of mono- and bifunctional reactive diluents on the printability and performance of resins based on acrylated epoxidized soybean oil (AESO) was explored. Polyethylene glycol di(meth)acrylates of different molecular weights were selected as diluents based on the viscosity and mechanical properties of their binary mixtures with AESO. Ternary mixtures containing 60% AESO, polyethylene glycol diacrylate (PEGDA) and polyethyleneglycol dimethacrylate (PEG200DMA) further improved the mechanical properties, water resistance and printability of the resin. Specifically, the terpolymer AESO/PEG575/PEG200DMA 60/20/20 (wt.%) improved the modulus (16% increase), tensile strength (63% increase) and %deformation at the break (21% increase), with respect to pure AESO. The enhancement of the printability provided by the reactive diluents was proven by Jacobs working curves and the improved accuracy of printed patterns. The proposed formulation, with a biorenewable carbon content of 67%, can be used as the matrix of innovative resins with unrestricted applicability in the electronics and biomedical fields. However, much effort must be done to increase the array of bio-based raw materials.

Fast-curing bio-based thermoset foams produced via the Michael 1,4-addition using fatty acid-based acetoacetate and acrylate

This study introduces an approach for creating bio-based polymer foams exploiting the Michael reaction that could be utilized as thermal insulation. The thermoset foams were developed using a second-generation bio-based feedstock – tall oil. Tall oil is a by-product of wood pulping in paper manufacturing and mainly comprises unsaturated fatty acids like oleic and linoleic acid. The study explores the use of tall oil-based acetoacetates (Michael donor) combined with various acrylates (Michael acceptor), petrochemical-based (bisphenol-A ethoxylate diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate), and bio-based (epoxidized soybean oil acrylate, epoxidized tall oil free fatty acids-based acrylate), to develop polymer foams that meet today's sustainability requirements. The developed polymer foams underwent extensive characterization. Matrix curing parameters were assessed by measuring changes in dielectric polarization during curing. Foaming parameters, including start and rise times, were precisely measured. The chemical composition of the foams was analysed using Fourier-transform infrared spectroscopy. Their thermal, thermo-mechanical, and mechanical properties were evaluated through thermal gravimetric analysis, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and compression tests. Additionally, the content of closed-cell and the coefficient of thermal conductivity were determined, further characterizing the foams as potential thermal insulation materials. Foams from bio-based donors with petrochemical-based acceptors exhibited a range of enhanced properties. They not only achieved high glass transition temperatures (up to 85 °C by DSC and up to 108 °C by DMA) but also displayed a spectrum of mechanical strengths (compression strength ranging from moderate to as high as ∼ 0.40 MPa) and good thermal isolation properties (thermal conductivity coefficient ∼ 31mW/(m·K)). Bio-based foams, derived from renewable resources, were characterized by properties fitting for flexible foam applications, such as low glass transition temperatures (down to −9.7 °C by DSC and down to 9.8 °C by DMA), reduced compression strength (approximately 0.011 MPa), and increased thermal conductivity (up to 46.7mW/(m·K)), indicating their potential utility in applications where flexibility is a key requirement.

High-performance pervious concrete using cost-effective modified vinyl ester as binder

Pervious concrete has a unique open-skeleton structure and high permeability, which effectively control water runoff, mitigate urban heat island effects, and reduce traffic noise in urban constructions. However, low strength, easy granulation, and poor durability often limit its application in pavement engineering. As a polymer binder, vinyl ester (VE) resin has high strength, wear resistance, durability, and corrosion resistance, which can remedy the shortage of pervious concrete. In this work, by optimizing the aggregate gradation and curing temperature, high-performance pervious concrete using VE resin as binder was fabricated. To further improve the performance of VE binder, renewable acrylated epoxidized soybean oil (AESO) and diphenylmethane diisocyanate (MDI) were used to increase the crosslinking degree of the resin and the durability of pervious concrete. When using 15% AESO and 10% MDI based on the weight of VE, the pervious concrete achieved an enhanced flexural strength of up to 7.72 MPa. A significant improvement was achieved by incorporating 50 wt% solid wastes copper slag into the pervious concrete, the compressive strength and flexural strength reached 37.72 MPa and 7.53 MPa, respectively. The permeability coefficient of the permeable concrete was 2.64 mm/s, and the connected porosity was 11.33%, which are higher than the requirements of China national standard. The satisfactory durability of pervious concrete was also verified through freeze-thaw, abrasion, and aging tests. This work offers a viable strategy for cost-efficient and sustainable high-performance pervious concrete, providing insights into the utilization of renewable feedstocks and solid wastes in civil materials.

Soybean Oil-Based 3D Printed Mesh Designed for Guided Bone Regeneration (GBR) in Oral Surgery.

This study aims to obtain a cyto-compatible 3D printable bio-resin for the manufacturing of meshes designed from acquired real patients' bone defect to be used in future for guided bone regeneration (GBR), achieving the goal of personalized medicine, decreasing surgical, recovery time, and patient discomfort. To this purpose, a biobased, biocompatible, and photo-curable resin made of acrylated epoxidized soybean oil (AESO) diluted with soybean oil (SO) is developed and 3D printed using a commercial digital light processing (DLP) 3D printer. 3D printed samples show good thermal properties, allowing for thermally-based sterilization process and mechanical properties typical of crosslinked natural oils (i.e., E = 12MPa, UTS = 1.5MPa), suitable for the GBR application in the oral surgery. The AESO-SO bio-resin proves to be cytocompatible, allowing for fibroblast cells proliferation (viability at 72h > 97%), without inducing severe inflammatory response when co-cultured with macrophages, as demonstrated by cytokine antibody arrays, that is anyway resolved in the first 24 h. Moreover, accelerated degradation tests prove that the bio-resin is biodegradable in hydrolytic environments.

Microscale interface mechanism of the improved high and low-temperature performance of modified bamboo fibres-reinforced asphalt mixture

ABSTRACT Using plant fibres to reinforce asphalt mixture and improve its road performance has attracted growing interest. To improve the interfacial adhesion between bamboo fibres (BFs) and asphalt matrix, BFs were treated with acrylate epoxidized soybean oil (AESO) and 4,4'-diphenyl methane diisocyanate (MDI). The high-temperature stability and low-temperature cracking resistance of the modified BFs-reinforced asphalt mixture were evaluated by the rutting and bending experiments, respectively. The dynamic stability at 60°C and the flexural strength at −10°C of the mixture with modified BFs were improved by 21.67% and 22.84%, respectively. Then, molecular dynamic simulations were implemented to investigate the effect of fiber modification on the interface properties. Simulation results showed that as the grafting density increased from 0 to 2.21 × 10–7 mol/m2, the binding energy increased by 277.2% and 159.3% at 65°C and −15°C, respectively, and the diffusion coefficient decreased by 50.8% and 27.7% at 65°C and −15°C, respectively. As the grafting density further increased to 4.43 × 10−7 mol/m2, the interface performance deteriorated because the dense grafted molecular chains inhibited the diffusion of asphalt to BF surfaces. This work provides an understanding of the interfacial mechanism for optimising the BF-reinforced asphalt mixtures.

Non-isothermal curing kinetics of soybean oil-based resins: Effect of initiator and reactive diluent

Soybean oil has been utilized as a raw material to develop biobased polymer to replace petroleum-based counterparts due to its abundance, renewability, and molecular designability. Acrylated epoxidized soybean oil (AESO) is a commercially available product and has been used in coatings, plasticizers, and composites. The curing of AESO resins normally refers to the free-radical polymerization of CC bonds, which is closely related to the types of initiators and reactive diluents (RDs). In this work, the processing parameters and curing kinetic mechanism of AESO resins were investigated based on the extrapolation method, Kissinger, Crane, and Friedman equations, and the influences of initiators and RDs on the curing of the resins were explored. Results indicated that the types of initiators significantly affected the processability and curing kinetics of AESO resins, and the curing temperatures and reaction activation energy of the resins were strongly associated with the decomposition temperature and activation energy of the initiators. The number of CC bonds and molecular structure of RDs considerably influence the curing characteristics of the resins. The addition of RDs endowed the reaction more complexity, and the activation energy significantly depended on the level of CC conversion.

Soybean oil‐based nanocomposites for dye adsorption: AESO‐chitosan‐graphene oxide synergy in water treatment

AbstractThis study presents the synthesis and characterization of a bio‐adsorbent (A‐C2‐G3) based on the acrylated epoxidized soybean oil (AESO) for the efficient removal of methylene blue (MB) dye from aqueous solutions. The adsorbent was synthesized by incorporating chitosan and nano graphene oxide into the AESO matrix, followed by crosslinking through the UV curing process. The effects of various parameters, including pH, contact time, initial dye concentration, adsorbent dosage, and ionic strength, on the adsorption performance were systematically investigated. The experimental data were best fitted by the Langmuir isotherm model, suggesting a monolayer adsorption process, with a maximum adsorption capacity of 263.87 mg g−1. The adsorption kinetics followed the pseudo‐second‐order model, indicating the significance of electron exchange between the adsorbate and adsorbent during the process. Three primary interaction mechanisms at the interface between MB and A‐C2‐G3 and the A‐C2‐G3 bio‐adsorbent were identified: electrostatic interactions, hydrogen bond formation, and π–π stacking. The reusability of the synthesized adsorbent was evaluated through a series of adsorption–desorption cycles, maintaining high adsorption capacities for up to three cycles. These findings highlight the potential of the AESO‐based bio‐adsorbent for effective MB dye removal from wastewater.

Optimizing rheological performance of unsaturated polyester resin with bio-based reactive diluents: A comprehensive analysis of viscosity and thermomechanical properties

Bio-based reactive diluents (RD) have been explored as alternative to styrene (STY) in unsaturated polyester resin (UPR). Among the different candidates, acrylated epoxidized soybean oil (AESO) and epoxidized linseed oil (ELO) stand out as triglyceride derivatives. Aditionally, methyl methacrylate (MMA), trimethylolpropane triacrylate (TMPTA) with acrylic functionality, limonene (LIM), and cinnamates (CINN), has been tested in different percentages. Firstly, their efficiency in viscosity reduction has been studied. Best results were obtained after the addition of MMA, LIM, and CINN at 5 wt%. These RD achieve a viscosity reduction of 48.9 %, 76.7 %, and 22.9 %, respectively, compared to the reference sample. The industrial utilization of CINN as RD is impeded by its reactivity, as has been evidenced by its prolonged reaction time (24 min) and low reaction enthalpy. The thermo-mechanical properties studied through flexural tests, Shore D hardness, Charpy's Impact test, and heat deflection temperature (HDT), show that the developed UPRs exhibit a decrease in resistant mechanical properties while doubling their ductility by using LIM and MMA as bio-based RD (1.88 and 2.15 kJ m−2, respectively). The HDT study results demonstrate a certain level of thermal stability when MMA is employed (56 °C), which is 15 % lower in the case of LIM. Therefore, it is observed that UPRs with bio-based RD exhibit balanced and improved thermo-mechanical properties in terms of ductility and strength, especially with the use of a 5 wt % of LIM and MMA.

UV-Cured Bio-Based Acrylated Soybean Oil Scaffold Reinforced with Bioactive Glasses.

In this study, a bio-based acrylate resin derived from soybean oil was used in combination with a reactive diluent, isobornyl acrylate, to synthetize a composite scaffold reinforced with bioactive glass particles. The formulation contained acrylated epoxidized soybean oil (AESO), isobornyl acrylate (IBOA), a photo-initiator (Irgacure 819) and a bioactive glass particle. The resin showed high reactivity towards radical photopolymerisation, and the presence of the bioactive glass did not significantly affect the photocuring process. The 3D-printed samples showed different properties from the mould-polymerised samples. The glass transition temperature Tg showed an increase of 3D samples with increasing bioactive glass content, attributed to the layer-by-layer curing process that resulted in improved interaction between the bioactive glass and the polymer matrix. Scanning electron microscope analysis revealed an optimal distribution on bioactive glass within the samples. Compression tests indicated that the 3D-printed sample exhibited higher modulus compared to mould-synthetized samples, proving the enhanced mechanical behaviour of 3D-printed scaffolds. The cytocompatibility and biocompatibility of the samples were evaluated using human bone marrow mesenchymal stem cells (bMSCs). The metabolic activity and attachment of cells on the samples' surfaces were analysed, and the results demonstrated higher metabolic activity and increased cell attachment on the surfaces containing higher bioactive glass content. The viability of the cells was further confirmed through live/dead staining and reseeding experiments. Overall, this study presents a novel approach for fabricating bioactive glass reinforced scaffolds using 3D printing technology, offering potential applications in tissue engineering.

Photocurable 3D printed anisotropic electrically conductive materials based on bio-renewable composites

The manufacturing industry is moving towards an environmentally friendlier and more sustainable economy by substituting fossil fuel-based materials for plant-based and related renewable resources obtained materials, such as soybean oil. The combination of these materials with electrically conductive fillers allows the fabrication of conductive tracks and sensors essential for the implementation of the internet of things (IoT) and Industry 4.0 concepts. Here, we've fine-tuned the combination of acrylated epoxidized soybean oil (AESO) and isobornyl methacrylate (IBOMA), considering factors like viscosity, photoreactivity, and physico-chemical properties, with the further addition of multiwalled carbon nanotubes (MWCNT) in varying amounts for selected formulations. The resulted materials obtained in films present gel times between 1 and 30 s, FTIR conversion between 75% and 50%, Tg in the range of 57–123 °C and crosslinking densities between 1.90 and 0.015 mmol/cm3. In addition, good MWCNT dispersion is achieved with conductivities as high as 1.4 × 10-4 S/m. The optimal formulation in terms of 3D printability was obtained for 0.6 wt% MWCNT content and AESO:IBOMA polymer matrix in a 50:50 ratio, showing a good fabrication precision for bulk and hollow structures (average dimensional differences between the model and printed objects of ± 100 mm). The 3D printed samples demonstrate anisotropic electrical conductivity ascribed to a MWCNT orientation that occurs during 3D printing process. The electrical conductivity values can vary in nearly 6 orders of magnitude depending on the orientation with respect to the printed pattern, − 6.6·10-3 S/m for parallel and 5.2·10-9 S/m for perpendicular - demonstrating the suitability for 3D printed electronic applications.

Fabrication and characterization of light-curing soybean oil-based epoxy resin applied for LCD additive manufacturing

In this work, we developed a photocurable vegetable oil-based resin with suitable curing properties for use in 3D printing. The acrylated epoxidized soybean oil (AESO), which was synthesized by the catalytic ring-opening reaction of the epoxidized soybean oil (ESO) and acrylic acid (AA), replaced the oligomer in conventional light-curing petroleum-based resins. In order to optimize the various properties of the soybean oil-based epoxy resin, the performance parameters of the resin were analyzed by numerical simulation. It was also combined with the parameters of the printing equipment to better guide the 3D printing process of the resin. The results showed that the esterification rate of acrylic acid (AA) with epoxidized soybean oil (ESO) was higher than that of methacrylic acid (MAA) during the arylation of epoxidized soybean oil (ESO), and AESO had moderate viscosity and was suitable as an oligomer for 3D printing. When the diluent of the oligomer has an ACMO to HDDA ratio of 3:2, the cured parts exhibit the optimum mechanical properties, hydrophobic properties, and thermal stability. All properties of the resins were further improved and giving the formulation the best 3D printing performance when 10% of epoxy resin E44 was added to the soybean oil-based epoxy resin. In addition, the numerical simulations indicate that this soybean oil-based epoxy resin formulation has the highest printing efficiency when the single layer thickness of the cured layer is set to 0.2 mm with the exposure time of 4 s, where the wavelength of UV is 405 nm and the light intensity is 40 W/m2. In conclusion, the light-curing resin developed through the soybean oil-based epoxy resin exhibits excellent performance in all aspects. The optimal printing process was also derived by combining the results obtained from numerical simulations of the resin performance parameters with the device parameters, which significantly improved the efficiency of the 3D printing with the fabricated soybean oil-based epoxy resin, making it has great application potential for the biomedical materials.

Fully bio‐based thermoset composites from UV curable prepregs: Vegetable oil acrylate impregnated hemp nanopaper

AbstractModern thermoset composite matrices are primarily prepared from petroleum‐based plastics, while reinforcements commonly consist of non‐renewable and energy‐demanding glass and carbon fibers. Herein, a non‐chemically treated hemp fiber‐reinforced composite was prepared from bio‐based components: hemp nanopaper (NP) and acrylated epoxidized soybean oil (AESO) or acrylated rapeseed oil (ARO). A commercial‐grade AESO was selected as a reference and compared to ARO prepared in a one‐step synthesis. The impregnation process was examined in detail by studying the impact of surface wetting, temperature, and vacuum on the composite structure. ARO has excellent fiber surface wettability, showing initial contact angles between 46.5° and 48.2° on hemp NP. A more than 10‐fold difference in viscosity between AESO and ARO was observed. ARO composite with 50 wt% hemp loading achieved a Young's modulus of 1.3 GPa, a tensile strength of 26 MPa, and a storage modulus of 4.4 GPa (at 20°C). The results are supplemented by scanning electron microscope analysis of composite morphology via liquid nitrogen fracture and tensile failure analysis, that is, fractography. Dielectric spectroscopy analysis shows that composites have the potential to replace epoxy/paper composite insulators.

3D-Printed Piezoelectric Scaffolds with Shape Memory Polymer for Bone Regeneration.

The application of piezoelectric nanoparticles with shape memory polymer (SMP) to 3D-printed piezoelectric scaffolds for bone defect repair is an attractive research direction. However, there is a significant difference in dielectric constants between the piezoelectric phase and polymer phase, limiting the piezoelectric property. Therefore, novel piezoelectric acrylate epoxidized soybean oil (AESO) scaffolds doped with piezoelectric Ag-TMSPM-pBT (ATP) nanoparticles (AESO-ATP scaffolds) are prepared via digital light procession 3D-printing. The Ag-TMSPM-pBT nanoparticles improve the piezoelectric properties of the AESO scaffolds by TMSPM covalent functionalization and conductive Ag nanoparticles. The AESO scaffolds doped with 10 wt% Ag-TMSPM-pBT nanoparticles (AESO-10ATP scaffolds) exhibit promising piezoelectrical properties, with a piezoelectric coefficient (d33) of 0.9 pC N-1 and an output current of 146.4 nA, which are close to the piezoelectric constants of bone tissue. In addition, these scaffolds exhibit good shape memory function and can quickly recover their original shape under near-infrared (NIR) light irradiation. The results of osteogenesis capability evaluation indicate that the AESO-10ATP scaffolds can promote osteogenic differentiation of BMSCs in vitroandbonedefectrepairin vivo, indicating the 3D-printed AESO-10ATP piezoelectric scaffolds may have great application potential forbone regeneration.

Modification of palm fiber with chitosan-AESO blend coating

Natural fibers are available as an essential substitute for synthetic fiber in many applications. However, the sensitivity of Chinese Windmill Palm or Trachycarpus Fortune Fiber (TFF) to water causes low interfacial bonding between the matrix and the fiber and at the end reduces the mechanical properties of the composite product. Alkaline treatment improves mechanical properties and does not affect water absorption. Hence, additional treatment in the coating is required. This study uses alkaline treatment and coating modification using blended chitosan and Acrylated Epoxidized Soybean Oil (AESO). Blend coating between AESO and chitosan is performed to increase water absorption and mechanical properties. TFF water resistance improved significantly after the coating, with water absorption of the alkaline/blend coating-TFF of 3.98 % ± 0.52 and swell ability of 3.156 % ± 0.17. This indicated that blend coating had formed a cross-link of fiber and matrix after alkalization. Thus, the single fiber tensile strength increased due to the alkaline treatment, and water absorption decreased due to the coating. The combination of alkaline treatment and blend coating on TFF brings excellent properties, as shown by the increase in tensile strength in both single fiber test and composite.

The feasibility of using several soybean oil-based derivatives for asphalt binder modification: A preliminary study

This paper examined the modification effects of three soybean oil-based derivatives for use in asphalt binder modification. Functional group grafting, free radical polymerization of monomers, and reversible addition-fragmentation chain transfer polymerization (RAFT) were used to prepare three soybean oil-based derivatives, respectively. The test results of proton nuclear magnetic resonance spectroscopy (1H NMR), gel permeation chromatography (GPC), and Fourier-Transform Infrared (FTIR) proved that the three bio-derivatives were successfully prepared. Performance grading (PG), multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), temperature-frequency sweep test and laser scanning confocal microscope (LSCM) tests were conducted to evaluate the modification effects of three derivatives on a base asphalt. The results indicated that poly (styrene-AESO) (PS-PAESO) reacted physically and chemically with the base asphalt binder during modification, and the development of a polymer elastic network improved the elasticity of base asphalt and thereby increased the rutting resistance and aging resistance. The incorporation of acrylated epoxidized soybean oil (AESO)and poly (acrylated epoxidized soybean oil) (PAESO)were found to improve the fatigue resistance of base asphalt, however, adversely affected its elasticity and high temperature performance. Additionally, it was found that PAESO with a higher molecular weight and polymer conversion might have the potential to ease the negative effects on high temperature performance. In general, three soybean oil-based derivatives have different emphases on asphalt modification, which could be used in various applications of asphalt in the paving industry with economic and environmental benefits.

Performance Enhancement of Asphalt Mixtures Enabled by Bamboo Fibers and Acrylated Epoxidized Soybean Oil

Bamboo fibers (BFs) have attracted much attention as a potential sustainable reinforcement material for asphalt pavements due to their high specific strength and modulus, low cost, renewability, and biodegradability. However, the key challenge of using BFs in asphalt mixtures is the weak interfacial adhesion between intrinsically hydrophilic BFs and the hydrophobic asphalt matrix. Therefore, this study proposed a surface modification method of BFs using acrylated epoxidized soybean oil (AESO) and 4,4-methylenediphenyl diisocyanate (MDI) to improve the fiber–matrix adhesion of the BFs/asphalt mixture. Fourier transform infrared spectroscopy and nuclear magnetic resonance analyses confirmed that the modified BF surface was grafted with AESO, and both of them were linked by MDI, thereby leading to the formation of a hydrophobic layer on the fiber surface. The water absorption of BFs significantly decreased after modification, and the interfacial adhesion between the modified BFs and the asphalt matrix remarkably improved. Adding the modified BFs to the mixture improved its mechanical properties, high-temperature stability, and low-temperature cracking resistance and decreased its moisture susceptibility. The work provides a feasible and industrial-scale method to enhance the road performance of the asphalt mixture by using renewable natural fibers and vegetable oils as modifying materials.

Effects of biopolymer functionalization and nanohydroxyapatite heat treatment on the tensile and thermomechanical properties of Bone-Inspired 3D printable nanocomposite biomaterials

Bone-inspired biopolymer nanocomposite grafts are an alternative to conventional bone substitutes if designed to offer a structure with adequate mechanical properties and biocompatibility. In this study, a set of novel 3D printable bone-inspired nanocomposite biomaterials was developed to investigate the effects of additional cross-linking of the biopolymer matrix and heat treatment of nHA particles on the tensile and thermo-mechanical properties of these nanocomposites used in extrusion-based 3D printing. We observed that additional functionalization of acrylated epoxidized soybean oil (AESO), as the main component of the biopolymer matrix, with additional methacrylate groups (mAESO), increased the strength and elastic modulus of extruded nanocomposites by more than three times, as well as doubled the glass transition temperature due to an increased degree of crosslinking in the functionalized matrices. The mAESO-based nanocomposite filaments demonstrated a strength safety factor of 1.5 against the minimum required standard mechanical properties for bone cement according to ISO standard5833. While heat treatment of nHA reduced the frequency of larger agglomerations, no significant difference in mechanical properties was observed. These novel 3D printable nanocomposite biomaterials with their improved strength, modulus and thermo-mechanical properties could be suitable candidates for fabricating complex ‘by design’ 3D printed grafts and scaffolds for bone reconstruction.