Resin Acids Research Articles

Mountain Pine Beetle Epidemic: An Interplay of Terpenoids in Host Defense and Insect Pheromones.

The mountain pine beetle epidemic has highlighted the complex interactions of bark beetles with conifer host defenses. In these interactions, oleoresin terpenoids and volatiles, produced and released by the host tree, can be both harmful and beneficial to the beetle's success in colonizing a tree and completing its life cycle. The insect spends almost its entire life, from egg to adult, within the bark and phloem of a pine host, exposed to large quantities of complex mixtures of oleoresin terpenoids. Conifer oleoresin comprises mostly monoterpenes and diterpene resin acids as well as many different sesquiterpenes. It functions as a major chemical and physical defense system. However, the insect has evolved host colonization behavior and enzymes for terpenoid metabolism and detoxification that allow it to overcome some of the terpenoid defenses and, importantly, to co-opt pine monoterpenes as cues for host search and as a precursor for its own pheromone system. The insect-associated microbiome also plays a role in the metabolism of conifer terpenoids.

Synthesis of a new bifunctional molecule based on castor oil and CO2 useful for polyurethanes

AbstractA new bifunctional biobased molecule, the carbonated methyl ester of ricinoleic acid maleate (CME‐RAM), useful for polyurethanes, was obtained from castor oil and CO2. This molecule bears carbonate and maleate functionalities that can participate, respectively, in aza‐Michael and aminolysis reactions. Maleate moieties are strong Michael acceptors and they were introduced into the fatty molecule using mild conditions. The synthetic steps include maleinization of castor oil followed by the simultaneous esterification and transesterification at 60°C. The subsequent stages were the epoxidation with acidic resins and the carbonation with CO2. The best results for epoxidation were obtained using Amberlite IR‐120 as catalyst at 48°C (84% conversion of double bonds). The carbonation of the oxirane ring with CO2 at 130°C, 6 MPa CO2 and 6 h reaction afforded 98% conversion of epoxides. It was demonstrated that aza‐Michael reaction of maleate groups was faster than aminolysis of carbonate groups, using hexylamine as a model molecule. CME‐RAM was oligomerized with ethylenediamine and used in the formulation of a conventional rigid polyurethane. Petrochemical polyol and isocyanate can be partially replaced by this bio‐based oligomer, producing a rigid material with a high percentage of green component and good mechanical properties.

Direct conversion of fructose to levulinic acid in water medium catalyzed by a reusable perfluorosulfonic acid Aquivion® resin

In this work, we reported an environmental-benign and cost-effective route for the direct conversion of fructose to levulinic acid. A commercial perfluorosulfonic acid resin in a pellet form, that is, Aquivion® P98, was shown as a water-tolerant and reusable solid acid catalyst. The influence of catalyst dosage, reaction temperature and reaction time on the dehydration of fructose was systematically investigated. It was disclosed that fructose was initially dehydrated to 5-hydroxymethylfurfural as the intermediate and it was subsequently hydrolyzed to produce levulinic acid and formic acid over the Brønsted acidic sites provided by Aquivion® P98. Under the optimum reaction conditions, 96% yield to levulinic acid at 100% conversion of fructose was obtained in water at 120 °C after 12 h. Productivity of levulinic acid reached 3.2 mol mol−1H+, an outstanding value reported in literature to date. The Aquivion® P98 catalyst can be regenerated through a simple ion-exchange method, and a stable yield of levulinic acid was maintained after six consecutive reuses. The controlled experiments proved that the acidic products, i.e., formic acid and levulinic acid, allowed working as homogeneous catalysts to accelerate the dehydration of fructose and the subsequent hydrolysis of 5-hydroxymethylfurfural.

Оптимизация процесса омыления таллового пека методом планирования эксперимента

Sustainable recycling of wood chemical production wastes is one of the current issues of modern technology. As a by-product of the pulp and paper industry, tall oil pitch has found application as a potential source of phytosterols. Phytosterols or plant sterols are natural compounds, polycyclic alcohols structurally similar to steroids. Due to their biological activity, phytosterols are used in such areas as pharmaceutics and cosmetology, as functional products, etc., which makes them commercially attractive. This paper considers the stage of saponification of tall oil pitch, which yields free phytosterols from their esters with fatty and resin acids. A central composite design complemented by six star points was chosen to determine the combined effect of the three factors and to plan the minimum number of experiments; the response surface methodology was used to determine the optimal values of the variables. Regression models showing the impact of the basic technological factors (excess alkali, temperature and duration of saponification) on the degree of saponification of phytosterols in saponified tall oil pitch and esters in the obtained extract were developed based on the experimental data. A statistical analysis of the models was carried out. Their validity has been proved by means of analysis of variance. The experimental and predicted values closely correlated. The developed mathematical models in the regression polynomial form enable to find the optimal values of the input process variables using the Minitab software while simultaneously reaching the maximum degree of saponification (98,1 %) with the minimum value of the ether number in the extract (4 mg KOH/g): saponification temperature – 121.7 °C, process duration – 3.18 h, and excess alkali – 100 %. Thus, reliable models for predicting the degree of saponification of phytosterols and the ester number in the extract were obtained. These models can be used in industrial saponification of tall oil pitch. For citation: Korshunov A.O., Lavrenteva E.A., Lazarev M.A., Radbil’ A.B. Optimization of Tall Oil Pitch Saponification by Experimental Design. Lesnoy Zhurnal [Russian Forestry Journal], 2022, no. 1, pp. 173–187. DOI: 10.37482/0536-1036-2022-1-173-187

Automated interlaminar reinforcement with thickness directional fiber arrangement for 3D printing

To improve interlaminar tensile strength, we developed a mechanism to automatically embed carbon fiber reinforced polymer (CFRP) and epoxy resin in the thickness direction by modifying a fused filament fabrication (FFF) 3D printer. To verify how the mechanical properties were improved by embedding continuous carbon fibers, CFRP filaments and epoxy resin were manually embedded into polylactic acid (PLA) resin, and tensile tests were conducted. The results showed that when the fiber volume fraction (Vf) was 6.4%, the tensile strength improved by up to 170% compared to the PLA specimen with 100% filling. To automatically embed the CFRP into the structure, we developed a tube pump as a device to pour the epoxy resin and a mechanism to automatically drop the CFRP into the structure, and attached it to the FFF 3D printer. Based on the tensile tests on the specimens made by automatically embedding CFRP and epoxy resin into the structure, we confirmed an increase in strength of approximately 45%, demonstrating the effectiveness of this method.

Poly(dimethyl siloxane) anti-corrosion coating with wide pH-responsive and self-healing performance based on core−shell nanofiber containers

• Hydrophobic core-shell fibers were prepared and added them to the poly(dimethyl siloxane) (PDMS) coating. • The maximum self-healing efficiencies of the fiber-PDMS coating in alkaline and acidic solution are 95.96% and 97.04%, respectively. • The hydrophobic effect of fiber-PDMS coating remains above 88.2% before and after abrasion. • The nanofiber network structure ensures the effective release of the healing agent and repeats self-healing. • The C 17 H 33 COO − absorbed on the scratch and AVR cured film reach a double repair function. In this research, core−shell electrospun fibers loaded with the shell of cellulose acetate and the core of oleic acid and alkyd varnish resin were synthesized and used within poly(dimethyl siloxane) (PDMS) to prepare self-healing and pH-responsive coatings for a steel substrate. The morphology of the electrospun fibers was characterized by scanning electron microscopy, transmission electron microscopy and confocal fluorescence microscopy. Thermo gravimetric analysis and Fourier transform infrared spectroscopy revealed that the self-healing agents were loaded successfully with a loading rate of 2.9%. The properties of the fiber-PDMS composite coating were characterized by water contact angle measurements, mechanical tests, electrochemical impedance spectroscopy, and scanning Kelvin probe. Results show that the maximum self-healing efficiencies of the fiber-PDMS coating in alkaline and acidic solution are 95.96% and 97.04%, respectively. The composition of the self-healing agents at the damaged part of the coating was verified by an infrared mapping test and using an energy dispersive spectrometer. In addition, the sandpaper abrasion test shows the hydrophobic effect of fiber-PDMS coating remains above 88.2% and decreases slightly through the addition of abrasion cycles. This research can pave the way for the industrial applications of pH-responsive self-healing coatings.

Correlation Between Biomass Burning Tracers in Urban and Rural Particles in Silesia\u2014Case Study

The major biomass burning tracers are thermal degradation products from the biopolymer cellulose, namely the didehydromonosaccharide derivatives levoglucosan, galactosan, and mannosan and the resin acid derivative dehydroabietic acid, with a minor contribution from β-sitosterol. Levoglucosan, galactosan, and mannosan were measured at two sites in Silesia, a rural (Rokitno) and industry region (Zabrze), during the winter of 2017/2018. The results showed that mean concentrations of the total tracers determined were 737 ng/m3 for Zabrze and 465 ng/m3 for Rokitno. Levoglucosan was the most abundant tracer; it was 83.2% of the determined tracers in Zabrze and 78.1% in Rokitno. The relative proportions of levoglucosan to mannosan have been used for source reconstruction of combustion-derived byproducts in atmospheric aerosols. The levoglucosan to mannosan ratio for Zabrze was 8.9 and for Rokitno 5.3; the levoglucosan to sum of mannosan and galactosan ratio was 6.2 and 3.8 for Zabrze and Rokitno, respectively. The correlation between tracers is high (0.73 to 0.97) and shows linearity. In order to compare the fuel type (by the coefficient of divergence (CD)) between different sites, the results from a previous work in health resort Krynica were used. The CD between Krynica and Rokitno as well as Krynica and Zabrze was equal to 0.633 and 0.712, respectively. The CD between Rokitno and Zabrze was equal to 0.175. Despite the biomass burning tracer measurements are mostly local, they have a huge impact on air pollution and climate changes.

Thermally Conductive and Superhydrophobic Polyurethane Sponge for Solar-Assisted Separation of High-Viscosity Crude Oil from Water.

The rapid and effective separation of high-viscosity heavy crude oil from seawater is a worldwide challenge. Herein, an ultralow density, photothermal, superhydrophobic, and thermally conductive polyurethane/polyaniline/hexagonal boron nitride@Fe3O4/polyacrylic-oleic acid resin sponge (PU/PANI/h-BN@Fe3O4/AR) was fabricated with a water contact angle (WCA) of 158°, thermal conductivity of 0.76 W m-1 K-1, density of 0.038 g cm-3, limited oxygen index (LOI) of 28.82%, and porosity of 97.97% and used for solar-assisted separation of high-viscosity crude oil from water. Photothermal components were composed of PANI and Fe3O4, while h-BN particles were used as thermally conductive and flame retardant fillers. Therefore, the illuminated sunlight irradiation on the modified sponge was converted to heat due to the activity of photothermal components. The produced heat was rapidly transferred to the environment due to the presence of h-BN for increasing the temperature of the high-viscosity crude oil and reducing oil viscosity that helped to promote its fluidity and effective absorption. The crude oil absorption capacity of this sponge increased from 4 to 57 g g-1 under irradiation of a sunlight simulator (power: 1 sun: 1 kW m-2) for 17 min due to oil viscosity reduction from 2.46 × 104 to below 100 mPa s followed by an increase in the surface temperature from 26 to 89 °C. Also, the oil absorption capacity was evaluated in a static state (172 g g-1 for chloroform), under different external magnetic fields (140.7 g g-1 for gasoline), and in a continuous state, which was 65,100 times of its own weight in the gasoline filtration process. The PU/PANI/h-BN@Fe3O4/AR sponge exhibited excellent stability against 20 times of reusing, mechanical compression, abrasion, immersing in various pH solutions, seawater, and high temperature. In all, the results confirmed that the prepared sponge is an excellent absorbent for organic solvents and highly viscous crude oil in the absence and presence of sunlight irradiation.

Column dynamic studies for lanthanum(III) and neodymium(III) sorption from concentrated phosphoric acid by strongly acidic cation exchange resin (SQS-6)

ABSTRACT In this work, solid-liquid extraction of lanthanum and neodymium ions by column technique from concentrated phosphoric acid solutions using the strongly acidic cation exchange resin was experimentally investigated. Measurements of breakthrough curves were measured as a function of column bed depth, initial metal concentration in the feed solution and flow rate. It was found that the breakthrough and time increased with the increase in bed depth and the total mass adsorbed by La(III) and Nd(III) increased with increasing bed depth. At higher initial metal concentrations, the column is quickly saturated, resulting in shorter breakthrough and exhaustion time. It was observed that with increasing the initial metal concentration from 0.10 to 0.50 g/L, the equilibrium adsorption capacities increase from 9.68 to 27.45 mg/g for La(III) and from 4.57 to 19.43 mg/g for Nd(III). Breakthrough time reaching saturation was increased significantly with a decrease in the flow rate. As the flow rate increased from 1.0 to 4.0 ml/min, the exhaustion time of La(III) and Nd(III) decreased from 135.0 to 40.0 min and from 90.0 to 35.0 min, respectively. The capacity of La(III) and Nd(III) was found to be 33.55 and 17.30 mg/g, respectively. The experimental sorption capacity and the time required for 50% adsorbate breakthrough (τ) are close to those calculated resulting from the Thomas and Yoon-Nelson model. These results indicate that the experimental data obey the Thomas and Yoon-Nelson model.

Superhydrophobic Coating Constructed from Rosin Acid and Tio2 Used as Blood Repellent Dressing

Superhydrophobic Coating Constructed from Rosin Acid and Tio2 Used as Blood Repellent Dressing

Epoxidation of Pumpkin Seed Oil (Curcurbita Maxima) using Acidic Ion Exchange Resin and its Kinetic and Thermodynamic Study

Epoxidation of Pumpkin Seed Oil (Curcurbita Maxima) using Acidic Ion Exchange Resin and its Kinetic and Thermodynamic Study

A three-dimensional (3D) printing approach to fabricate an isolation chip for high throughput in situ cultivation of environmental microbes.

The full plethora of environmental bacteria is often poorly represented in vitro as the majority remain difficult, if not impossible, to culture under standard laboratory settings. These bacteria often require native conditions for the formation of cell masses that collectively have higher chances of survival. With that, a 3D-printed version of the isolation chip (iChip) was used to cultivate bacteria from a tropical peat swamp in situ prior to growth and maintenance in vitro. Briefly, plates made from either acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), or epoxy resin were tested in terms of their usability and durability under acidic conditions similar to those of peat matter. The epoxy resin plates were then found to be most optimal for the sampling conditions. Peat soil samples were collected from the base of a Koompassia malaccensis tree and reconstituted in molten 10% (wt/vol) tryptone soy agar (TSA) prior to inoculation. The iChips were subsequently assembled and buried in the site of origin. As a comparison, bacteria from the same soil sample were cultivated directly on TSA and incubated at 28 °C for two weeks. Thereafter, agar plugs from the iChip were transferred to TSA plates to allow microcolonies within each plug to grow. Each pure isolate from both cultivation approaches that grew was then pooled and extracted for total DNA prior to 16S rRNA gene amplification and sequencing via Illumina MiSeq. Taxonomic abundance comparison revealed that the bacterial taxa at the level of order were significantly different between the two approaches, particularly in the orders, Burkholderiales, Xanthomonodales, Enterobacteriales, and Actinomycetales (differences of 12.0, 7.1, 8.0, and 4.2%, respectively). This indicated that the 3D-printed iChips present a possible low-cost tool for the isolation of bacterial genera that may not be able to grow on media directly in vitro.

Poly(Hydroxamic Acid) Resins and Their Applications

Poly(Hydroxamic Acid) Resins and Their Applications

Mechanical Properties of Polylactic Acid Resin Composite Filament Reinforced by SUS304 Wire

The purpose of this study is to investigate the mechanical properties of composite filament which made from polylactic acid resin and SUS304 wire for Fused Deposition Modeling. Both of PLA resin and SUS304 wire were supplied to heated extruder for covering the SUS304 wire with melted PLA. The feed rate of both materials was individually controlled by controlling the number of revolutions of stepper motors. In this study, three types of SUS304 wires were used to investigate the effect of surface roughness of wire on the tensile characteristics of composite filament. The surface of SUS304 wire was modified by chemical etching or mechanical grinding to control the surface roughness. For comparing, two modified wires and as received SUS304 wire were used for following experiments. The tensile characteristics of composite filament was investigated by using universal testing machine. Tensile test results showed that the tensile modulus and strength of composite filament was improved compared that of original PLA filament. The pull-out test of composite filament was also revealed that the apparent interfacial shear strength between PLA and SUS304 wire was improved when the surface roughness of SUS304 wire was high. Moreover, when the surface roughness of SUS304 wire was high, the fracture morphology of composite filament was changed.

Effect of Resin Acid and Zinc Oxide on Immune Status of Weaned Piglets Challenged With E. coli Lipopolysaccharide

With the ban of zinc oxide (ZnO) at high dosages in piglet diets in Europe by 2022, alternative nutritional solutions are being tested to support piglet immune defence during their weaning, the most critical and stressful moment of pig production. The present study evaluated the effect of zinc oxide (ZnO; 2,500 mg/kg diet) and resin acid concentrate (RAC; 200 mg/kg diet) on the immune defence of weaned piglets challenged with lipopolysaccharide (LPS). Piglets were challenged at days 7 and 21 post-weaning, and blood was sampled 1.5 and 3.0 h after each challenge to determine serum levels of pro- and anti-inflammatory cytokines. The levels of serum tumour necrosis factor alpha (TNF-α) and interleukin 8 (IL-8) increased at days 7 and 21, and those of IL-6 at day 21 when challenged piglets were fed a diet supplemented with ZnO. In challenged piglets fed with RAC, the serum levels of IL-1β, IL-6, IL-8, IL-10 and TNF-α were increased at days 7 and 21, except for that of IL-1β, which was not affected at day 21. The increased levels of these cytokines indicate the successful immune-modulatory effect of ZnO and RAC, which appears as a candidate to replace ZnO in weaned piglets' diets.

Electromagnetic and microwave absorption properties of Ti3SiC2/AgNWs/ acrylic acid resin composite coatings with FSS incorporation

In this work, Ti3SiC2/AgNWs composite powders were synthesized by an alcohol thermal reaction method and added in acrylic epoxy resin to prepare a microwave absorption coating. The characteristics of the composite powders and coatings were analyzed. XRD results verified the successful preparation of AgNWs, and SEM images revealed the AgNWs were intertwined with Ti3SiC2 powders. The introducing of AgNWs was helpful to form a conductive network inside the coatings. And the complex permittivity of the coating was enhanced with the increasing content of AgNWs. What’s more, the impedance matching condition and attenuation loss ability of the coatings were optimized, which contributed to enhancing the microwave absorbing performances. The Ti3SiC2/AgNWs/acrylic acid resin coating containing 30% AgNWs exhibited the optimum microwave absorption performance. For the coating with 2.0 mm thickness, the lowest RL value of − 31.2 dB was obtained at 10.34 GHz, and the effective absorption bandwidth has reached to 3.22 GHz (9.18–12.4 GHz). After incorporating with frequency selective surface (FSS), the microwave absorption performance in the low frequency range is significantly enhanced. The results show that the combination of Ti3SiC2/AgNWs with FSS can tailor the absorption bandwidth and develop a novel microwave absorbing material.

Synthesis of Epoxy Methacrylate Resin and Coatings Preparation by Cationic and Radical Photocrosslinking.

This work involves the synthesis of hybrid oligomers based on the epoxy methacrylate resin. The EA resin was obtained by the modification of industrial-grade bisphenol A-based epoxy resin and methacrylic acid has been synthesized in order to develop multifunctional resins comprising both epoxide group and reactive, terminal unsaturation. Owing to the presence of both epoxy and double carbon–carbon pendant groups, the reaction product exhibits photocrosslinking via two distinct mechanisms: (i) cationic ring-opening polymerization and (ii) free radical polymerization. Monitoring of EA synthesis reactions over time using PAVs, MAAC and NV parameters, and the FT-IR method reveals that esterification reactions proceed faster at the start, exhibiting over 40% of conversion within the initial 60 min, which can be associated with a relatively high concentration of reactive sites and low viscosity of the reaction mixture at the initial reaction stage. With the further increase in the reaction time, the reaction rate tends to decrease. The control of the EA synthesis process can guide how to adjust reactions to obtain EAs with desired characteristics. Based on obtained values, one can state that the optimum synthesis time of about 4–5 h should be adopted to prepare EAs having both epoxy groups and unsaturated double bonds. The structure of the obtained EA was confirmed by FT-IR and NMR methods, as well as the determination of partial acid value and epoxy equivalent. Samples at various stages of synthesis were cured with UV radiation in order to study the kinetics of the process according to cationic and radical polymerization determined via photo-differential scanning calorimetry (photo-DSC) and real-time infrared spectroscopy (RT-IR) and then the properties of the cured coatings were tested. It turned out that the cationic polymerization was slower with a lower conversion of the photoreactive groups, as compared to the radical polymerization. All the obtained EA coatings were characterized by good properties of cured coatings and can be successfully used in the coating-forming sector.

Study on the reduction of soil adhesion and tillage force of bionic cutter teeth in secondary soil crushing

Fine breakage of topsoil blocks in a seedbed has an important impact on operation quality of planting and harvesting mechanisation. Structure and material of the cutter teeth are one of the key elements in fine topsoil breaking. In order to improve the tillage performance of crushing cutter teeth, a bionic cutter teeth prototype inspired by the badger claw toe is proposed. In addition, the surface of the cutter teeth was modified by anti-adhesion material coating. The simulation model was established in ANSYS/LS-DYNA software and simulated soil cutting process was analysed. The results showed that cutter teeth with bionic structure could effectively reduce the average cutting resistance, cutting stress, soil energy, and maximum cutting resistance, obtaining soil cutting effect. By employing Fourier transform infrared spectroscopy (FTIR), water contact angle combined with abrasion resistance tests, mixed polytetrafluoroethylene (PTFE) and fluorosilicone acrylic acid (FAA) resin coatings after sintering were found to combine well with the cutter teeth. When the coating thickness was 10 μm, the tillage force was the lowest, and the abrasion resistance was the highest, which resulted in best comprehensive performance of cutter teeth. Scanning electron microscope (SEM) images indicated that the coating material can protect the surface and prevent abrasion. Field test results also proved that uncoated and coated bionic cutter teeth had lower energy consumption and soil adhesion, especially for the coated bionic cutter with 10 μm thickness. The results of this study could provide an important reference for designing a more efficient rotating tillage tools. • A bionic cutter teeth prototype inspired by the badger claw toes. • Bionic structure achieved fine crushing and improved tillage performance. • Mixed PTFE and FAA coating protected cutter teeth surface and prevented abrasion. • Bionic structure and coating had superimposed effect on anti-adhesion/resistance.

Mechanical and medical imaging properties of 3D-printed materials as tissue equivalent materials.

Three materials of polylactic acid (PLA), polyamide 12 (PA12), and light curing resin (LCR) were used to construct phantom using 3D printing technology. The mechanical and medical imaging properties of the three materials, such as elastic modulus, density, effective atomic number, X‐ray attenuation coefficient, computed tomography (CT) number, and acoustic properties, were investigated. The results showed that the elastic modulus for PLA was 1.98 × 103 MPa, for PA12 was 848 MPa, for LCR was 1.18×103 MPa, and that of three materials was close to some bones. In the range of 40∼120 kV, the X‐ray attenuation coefficient of three materials decreased with increasing tube voltage. The CT number for PLA, PA12, and LCR was 144, −88, and 312 Hounsfield units at 120 kV tube voltage, respectively. The density and the effective atomic number product (ρ*Z eff) were computed from three materials and decreased in the order of LCR, PLA, and PA12. The acoustic properties of materials were also studied. The speeds of sound of three materials were similar with those of some soft tissues.

A novel approach for synchronous transformation and extraction of psoralen from fig (Ficus carica L.) leaves based on polarity of different macroporous adsorption resins

In this study, using fig leaves as materials, strong acidic cation exchange resin of D072 with –SO3H functional group was selected as catalyst to promote the conversion of psoralen-glucoside (PO) to psoralen (PSO), and the strong acidic cation exchange resin transformation method (SACERTM) was developed for efficient extraction of PSO from fig leaves. Under the optimized extraction conditions, the yield of PSO was 36.74 mg/g. The transformation efficiency of PO to PSO reached 70.41% using 2 g of D072 resin as catalyst. Then, PSO in fig extract was enriched efficiently by X-5 macroporous adsorption resin (MAR). After eluting with 14-fold of column volume of 70% ethanol at 0.64 BV/h of elution flow rate, the purity of PSO was 24.8-fold higher than before enrichment. The results show that SACERTM combined with MAR purification is an efficient method for extracting and enriching PSO from fig leaves.