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The micro-wrinkles on polymer film surfaces endow the films with unique optical properties. This study utilized a stereomicroscope for in-situ observation of the curing process of UV-curable self-wrinkled polyurethane acrylate films, investigating the critical time and microstructures during curing under varying UV intensities (5.6, 8.0, and 11.4 mW/cm2), photoinitiator concentrations (C PI , 1.6 wt% and 2.0 wt%), and film thicknesses (h film , 60 and 120 μm). The acrylate conversion, surface gloss, arithmetic mean roughness (Ra), and micro-wrinkles' dimensions were compared across different curing parameters. Results demonstrated that the acrylate conversion increased with higher UV intensity, and continued to rise even after the surface micro-wrinkles stabilized. The UV intensity had the greatest influence on the critical time T 1 (from initial UV exposure to appearance of microstructures), with higher UV intensity reducing T 1. UV intensity, C PI , and h film significantly impacted the critical time T 2 (from microstructure appearance to stable wrinkle formation), with T 2 decreasing as these three parameters increased. The sample F 2.0 – 120−H exhibited the shortest T 1 and T 2 , recorded at 90 s and 82.3 s, respectively. The amplitude (A), wavelength (λ), and A/λ values of the micro-wrinkles increased with h film but decreased with higher C PI and UV intensity. Moreover, a higher A/λ value correlates with an increased Ra and decreased gloss values. However, incomplete curing of some films can lead to relaxation and affect their gloss and Ra values. Finally, cured films demonstrated high transmittance and haze, with the illuminance of integrated LED chips covered by these films increasing by up to 27.5 %, indicating a promising application potential for self-wrinkled films in the optical field. [Display omitted] • Prepare self-wrinkled film using only a medium-pressure mercury lamp in ambient air • Conduct in-situ observation of the wrinkling process using a stereomicroscope • Illuminance of LED chips covered with self-wrinkled film can increase by up to 27.5 % [ABSTRACT FROM AUTHOR]

Self-matting coatings, featuring micro-winkles for low gloss and a soft tactile feel, were obtained by employing 222 nm far-UVC radiation emitted by a Krypton-Chloride excimer lamp applied to UV-curable waterborne polyurethane acrylate wood coatings. The 222 nm far-UVC penetrates the wet film's top layer (a few micrometers) to induce C C to ·C−C· biradical, participating in the free radical polymerization process and resulting in the top layer completing gradient curing first. Subsequently, the thicker lower layer begins gradient curing due to the radical produced by the photoinitiator, and volume cure shrinkage induces internal stress, resulting in the formation of micro-wrinkles. This study systematically investigated the effects of varied photoinitiator concentrations (2.0 wt% and 3.0 wt%), film thicknesses (60 μm and 110 μm), and curing temperature (low: 28.3 °C, high: 37.4 °C) on the coating films' properties. At low curing temperature, the optimal matte film is characterized by gloss values of 3.6 GU at 60° and 5.6 GU at 85°. When maintaining consistent coating thickness and curing temperature, gloss values increased with higher photoinitiator concentration, while roughness values decreased. Conversely, with the same photoinitiator concentration and curing temperature, gloss values decreased as coating film thickness increased, while roughness values increased. At high curing temperature, the coating film exhibits the best matte effect with gloss values of 2.8 GU at 60° and 3.6 GU at 85°. Film gloss values experienced a slight reduction with increased film thickness or photoinitiator concentration. Scanning electron microscope observations indicated that coating films cured at high temperature displayed higher micro-wrinkles with folding than films cured at low temperature. This study demonstrates that self-matting coating films exhibit favorable physical and mechanical properties, and the curing process can occur directly in ambient air. The utilization of 222 nm far-UVC irradiation holds the potential for the large-scale production of matte coatings for wooden products. • Ultra-low gloss self-matting film, no >4.0 GU at 85°, using UV-WPUA coating • Obtain the film utilization 222 nm KrCl* excimer lamp for irradiation in ambient air • Modulating film gloss by adjusting curing temperature [ABSTRACT FROM AUTHOR]

Self-matting film with micro-wrinkles on the surface has gained popularity for its desirable attributes, including low-gloss and a pleasant tactile sensation when in contact with the human skin. This study prepared films with varying thicknesses (h film) using UV-curable waterborne polyurethane acrylate resins containing different concentrations of photoinitiator (C PI). The effects of two variables on the acrylate conversion, micromorphology, gloss value, roughness, water contact angle (WCA), and friction behavior of the films were investigated. The findings indicate that, when the C PI remains constant, an increase in h film leads to a reduction in both acrylate conversion and gloss value of the film. Moreover, the amplitude (A), wavelength (λ), and A/λ of micro-wrinkles, along with the Ra, increase with h film , while WCA remains relatively unaffected. Conversely, maintaining a constant h film while increasing C PI results in higher acrylate conversion and gloss value. The A and λ of micro-wrinkles and the Ra decrease, while WCA exhibits a slight decrease. Furthermore, this study investigates the impact of varying oxygen concentrations ([O 2 ]) on the equilibrium state of the polymerization rate and the oxygen inhibition rate. The results demonstrate that decreasing [O 2 ] leads to increased acrylate conversion, reduced A of micro-wrinkles, and a transition from low-gloss to high-gloss film as indicated by gloss value measurements. Nanoindentation tests revealed that as the [O 2 ] decreases from 21 % (air) to 0 %, the hardness of the film increases from 0.13 GPa to 0.23 GPa, while the elastic modulus of the film decreases from 23.23 GPa to 3.53 GPa. The findings provide valuable insights into optimizing the synthesis parameters to achieve desired film characteristics, which are crucial for the development of self-matting films with superior aesthetic and tactile qualities. [Display omitted] • Self-matting film prepared in ambient air by using medium-pressure mercury lamp only • Study the equilibrium state between polymerization and oxygen inhibition rates • Study the properties of films cured at different oxygen concentrations [ABSTRACT FROM AUTHOR]

In order to increase the curing rate of polymeric diphenylmethane diisocyanate (PMDI) resin, different contents of lignin-containing cellulose nanofibrils (L-CNFs) were blended into the PMDI. Differential scanning calorimetry (DSC) was used to examine how the addition of L-CNFs influences the curing kinetics of PMDI resin. The activation energy (Ea) of the curing reaction of PMDI/L-CNF systems was calculated using the Kissinger, Friedman and Flynn-Wall-Ozawa model-free methods. The results showed that Ea values calculated by the aforementioned three methods varied in a similar trend with the increase in the L-CNF content. Adding L-CNFs could decrease the Ea value of the curing reaction of PMDI and speed up the curing reaction. The acceleration of the cure rate of the PMDI resin upon the addition of L-CNFs may be attributable to the effective dispersion of the L-CNFs into the PMDI resin as well as the reaction between the hydroxyl (-OH) groups of the L-CNFs and the isocyanate (-NCO) groups of the PMDI. [ABSTRACT FROM AUTHOR]

To improve the mechanical properties and reduce the heterogeneous properties of 3D printed materials, a novel structure inspired by wood microstructure was designed. A methacrylate (MA)/cellulose nanocrystal (CNC) mixture was impregnated into the structure (infill density controllable 3D printed structure) and cured at elevated temperature. The specific tensile strength and modulus increased considerably after impregnation, especially at 80% infill density. The morphology of printed composites indicated that good interfacial adhesion was obtained by impregnation of MA/CNC mixture and curing at elevated temperature. Thermal stability of the printed composites was also improved, as shown by increases in the temperature at maximum rate of weight loss and the glass transition temperature. Nanoindentation measurement showed that the printed sample was more homogeneous, as evidenced by the comparable elastic modulus and hardness at different positions of the sample. [ABSTRACT FROM AUTHOR]

Various contents of lignin-coated cellulose nanocrystals (L-CNC) were incorporated into methacrylate (MA) resin and their mixture was used to prepare nanocomposites via 3D stereolithography (3D-SL) printing. Gaps were found between the L-CNC and MA matrix in 3D-SL printed nanocomposites before postcure. However, gaps decreased after postcure due to interactions between the L-CNC and MA molecules. Mechanical properties increased with the addition of 0.1% and 0.5% L-CNC after postcure, and the thermal stability was improved at 0.5% L-CNC. Dynamic mechanical analysis demonstrated that incorporation of L-CNC increased the storage modulus in the rubbery plateau. The loss factor had two transition regions, which gradually changed by merging together with increasing L-CNC content, and a broadening of the transition region was observed after postcure. In particular, the mechanical and thermal properties of 3D-SL printed nanocomposites, after postcure, exhibited higher improvement than those before postcure. [ABSTRACT FROM AUTHOR]

Modification with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) can dimensionally stabilize wood and improve the durability, but does not change its flammability. In this study, fire retardant (methylolated guanylurea phosphate (MGUP) and boric acid (BA)) was incorporated in DMDHEU to treat Oak wood ( Quercus rubra L.). Thermogravimetry and cone calorimetry showed that combinative treatment with DMDHEU/MGUP/BA caused a considerable decrease in the pyrolysis temperature, heat release, and smoke production. A full-scale fire test indicated that DMDHEU/MGUP/BA modified wood can be classified as B fl -s1. Findings demonstrated that combinative treatments can substantially reduce the fire risk for DMDHEU-modified wood, making them especially useful for application in public settings. [ABSTRACT FROM AUTHOR]

To improve the interfacial adhesion and dispersion of a poplar fiber in a polylactic acid (PLA) matrix, maleic anhydride (MA) and a silane coupling agent (KH550) were used to modify the poplar fiber. The poplar fiber/PLA composites were produced with different modifier contents. The mechanical, thermal, rheological, and physical properties of composites were investigated. A comparison of different natural fiber modifications on the properties of composites was also analyzed. The results showed that both MA and KH550 could improve the interfacial adhesion between the poplar fiber and PLA, resulting in the enhanced mechanical properties of the composite, with 17% and 23% increases of tensile strength for 0.5% MA and 2% KH550, respectively. The thermal properties of the composites were improved at 6% KH550 (a 9% enhancement of T90%) and decreased at 0.5% MA (a 6% decrement of T90%). The wettability of the composites obtained a 11.3% improvement at 4% KH550 and a 5% reduction at 4% MA. Therefore, factors such as mechanical properties, economic efficiency, and durability should be carefully considered when choosing the modifier to improve the property of the composite. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate the presence of residual lignin in cellulose fibers on the efficiency and energy consumption during nanofibers processing. Four kinds of lignin-containing cellulose nanofibers (LCNFs) from switchgrass, yellow poplar, hybrid poplar, and pine, respectively, were isolated via organosolv fractionation coupling mechanical grinding. Nanofibrils were observed after organosolv fractionation. The details of their morphological features, chemical structures, water retention value (WRV), and thermal degradation characteristics were revealed and compared. Mean diameters of nanofibers separated from switchgrass, yellow poplar, hybrid poplar, and pine were 27.9 nm, 25.4 nm, 24.6 nm, and 21.5 nm, respectively. The presence of lignin for the four types of LCNFs led to a decrease in energy consumption and an increase in WRV, among which pine nanofibers show the best with an average energy consumption of 0.511 kWh/kg and a WRV of 537%. It was also demonstrated that increasing lignin content for LCNFs could contribute to the sample's thermal stability. In conclusion, exact benefits of residual lignin for nanofiber will facilitate its preparation process and extend its application. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) are green reinforcing materials, and their potential has been evaluated in the preparation of waterborne UV-curable resin composites with high-performance. Herein, we present a novel and scalable approach for preparing surface-modified CNCs with acrylic-based polymers to strengthen the compatibility and interaction between CNCs and UV-curable resins. Using tert-butyl acrylate as the monomer, the nanocellulose grafted copolymer CNC-g-PtBA was successfully synthesized via atom transfer radical polymerization (ATRP) in the presence of a macromolecular initiator. Then, the CNC-g-PtBA is blended into the acrylic resin as a nanofiller to prepare the UV-curable nanocomposite. The results indicated that the contact angle of the CNCs increased from 38.7° to approximately 74.8°, and their thermal stability was significantly improved after graft modification. This contributed to the effective alleviation of the agglomeration phenomenon of nanocomposites due to the high hydrophilicity of pure CNCs. Notably, not only was the UV curing efficiency of the nanocomposites greatly increased but the mechanical properties were also further enhanced. Specifically, with the addition of 0.5 wt% CNC-g-PtBA, the curing time of the nanocomposite was shortened from >30 mins down to approximately 6 mins, and the bending strength was increased from 10 MPa for the original resin and 5 MPa for the addition of pure CNCs to 14.3 MPa, and the bending modulus was also greatly increased (up to approximately 730 MPa). Compared to pure CNCs, they are compatible with the resin, exhibiting high mechanical strength and flexibility, and have virtually no effect on the light transmission of the nanocomposites. Additionally, dielectric analysis (DEA) was used to monitor the dielectric constant and conductivity of the UV-curable nanocomposites in real time to further characterize their curing kinetics. The permittivity of these nanocomposites increased by 125 % compared to pristine resin, which shows potential for applications in high dielectric composites or for improving electrical conductivity. This work provides a feasible method for preparing UV-curable nanocomposites with high curing efficiency and permittivity, realizing a wider application of this high-performance nanocomposite. [Display omitted] • Modified CNCs via ATRP with controllable particle size distribution and molecular structure • Modified CNCs showed superior interfacial compatibility with waterborne UV-curable resin. • Dielectric analysis characterized curing properties of the UV-curable nanocomposites. • UV-curable nanocomposites exhibited high curing efficiency and dielectric constant. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) are green reinforcing materials, and their potential has been evaluated in the preparation of waterborne UV-curable resin composites with high-performance. Herein, we present a novel and scalable approach for preparing surface-modified CNCs with acrylic-based polymers to strengthen the compatibility and interaction between CNCs and UV-curable resins. Using tert-butyl acrylate as the monomer, the nanocellulose grafted copolymer CNC-g-PtBA was successfully synthesized via atom transfer radical polymerization (ATRP) in the presence of a macromolecular initiator. Then, the CNC-g-PtBA is blended into the acrylic resin as a nanofiller to prepare the UV-curable nanocomposite. The results indicated that the contact angle of the CNCs increased from 38.7° to approximately 74.8°, and their thermal stability was significantly improved after graft modification. This contributed to the effective alleviation of the agglomeration phenomenon of nanocomposites due to the high hydrophilicity of pure CNCs. Notably, not only was the UV curing efficiency of the nanocomposites greatly increased but the mechanical properties were also further enhanced. Specifically, with the addition of 0.5 wt% CNC-g-PtBA, the curing time of the nanocomposite was shortened from >30 mins down to approximately 6 mins, and the bending strength was increased from 10 MPa for the original resin and 5 MPa for the addition of pure CNCs to 14.3 MPa, and the bending modulus was also greatly increased (up to approximately 730 MPa). Compared to pure CNCs, they are compatible with the resin, exhibiting high mechanical strength and flexibility, and have virtually no effect on the light transmission of the nanocomposites. Additionally, dielectric analysis (DEA) was used to monitor the dielectric constant and conductivity of the UV-curable nanocomposites in real time to further characterize their curing kinetics. The permittivity of these nanocomposites increased by 125 % compared to pristine resin, which shows potential for applications in high dielectric composites or for improving electrical conductivity. This work provides a feasible method for preparing UV-curable nanocomposites with high curing efficiency and permittivity, realizing a wider application of this high-performance nanocomposite. [Display omitted] • Modified CNCs via ATRP with controllable particle size distribution and molecular structure • Modified CNCs showed superior interfacial compatibility with waterborne UV-curable resin. • Dielectric analysis characterized curing properties of the UV-curable nanocomposites. • UV-curable nanocomposites exhibited high curing efficiency and dielectric constant. [ABSTRACT FROM AUTHOR]

Poplar wood ( Populus adenopoda Maxim) has been modified by glucose (GLC) in the presence of citric acid (CA) or 1,3-dimethylol-4,5-dihydroxy ethyleneurea (DM) as crosslinker agents. GLC can penetrate easily the wood cell walls, and after crosslinking, the cell wall is bulked. At 20% GLC concentration level, the leaching ratio of GLC incorporated into wood decreased from 73% to 15% in the presence of 10% CA or DM. The crosslinking efficiency of DM was higher than that of CA. The fixed chemicals in the cell walls caused ca. 6% permanent bulking, namely, a 43% reduction in volumetric swelling after water saturation. FTIR spectroscopy shows that GLC can be activated in the presence of a catalyst; however, the reaction of GLC with a wood polymer is very limited. Scanning electronic microscopy (SEM) reveals that some of the chemicals remained located in the cell lumens. The findings demonstrate that GLC alone is not efficient, but joint treatment of GLC with crosslinkers is a feasible way of wood modification. [ABSTRACT FROM AUTHOR]

Wood vinegar, resulting from the pyrolysis of wood-waste materials, exhibits herbicidal activity against various broadleaf and grass weeds. The objectives of this research were to investigate the composition, property, and efficacy of wood vinegar resulting from the pyrolysis of pruned apple (Malus × domestica Borkh.) tree branches for control of annual bluegrass (Poa annua L.). The composition of wood vinegar was analyzed using gas chromatography-mass spectrometry. Water was the major component in wood vinegar and accounted for 85% by weight. Various organic compounds including acids, alcohols, aldehydes, ketones, phenols, esters, nitrides, and carbohydrate were identified but the major organic compound was acetic acid. Treatments were wood vinegar solutions diluted with distilled water at 0%, 6%, 12%, 25%, 50%, and 100% concentrations. By 20 days after treatment (DAT), when foliarly applied at 2800 L ha−1, the lowest concentration of wood vinegar (6%) only caused 23% annual bluegrass injury, while the highest concentration (100%) caused 95% injury; and the concentration of wood vinegar required to induce 50% visual injury (I 50) measured 14%. By 20 DAT, when wood vinegar applied to soil at 110 L m−3, the lowest concentration of wood vinegar (6%) caused 26% visual injury, but the highest concentration of wood vinegar (100%) caused 86% visual injury, and I 50 measured 21%. In field experiments, the time required to control 50% annual bluegrass measured 13.3 and 6.6 DAT when wood vinegar concentrations at 50% and 100% applied at 2800 L ha−1. Overall, these results indicate that wood vinegar derived from apple tree branches can be used for controlling annual bluegrass. • Wood vinegar is produced from the pyrolysis of pruned apple tree branches. • Wood vinegar contains a variety of organic compounds including acetic acid. • Foliar- or soil- applied wood vinegar adequately controlled annual bluegrass. • Wood vinegar from apple tree branches can be used for weed management. [ABSTRACT FROM AUTHOR]

Efficient lead removal from metal-containing wastewater, such as acid mine drainage (AMD), is an important step in environmental purification and secondary resources recovery. In this paper, a novel approach by mechanochemically activating CaCO 3 through simply wet ball milling in metal-containing solution was developed, where selective Pb2+ precipitation in the form of PbCO 3 was achieved based on its reaction with the CO 3 2− from the activated CaCO 3. By such milling operation, the removal efficiency of Pb2+ from aqueous solution could reach over 99%, while more than 99% Zn2+ (as well as Mn, Ni and Cd) was remaining in the solutions, demonstrating the feasibility and high effectiveness of precipitating Pb2+ and serving the purpose of recovering other metals without Pb impurity. The solubility differences between Pb carbonate and other carbonates of Zn, Mn, Ni or Cd were understood to be the main pathway and using CaCO 3 would offer an easy operation and environmental friendly process to purify the metals-containing wastewater by precipitating Pb, compared with the difficulties when using alkaline neutralization to treat them. In addition, basic zinc carbonate (a zinc-containing ore waste) as an alternative precipitant to CaCO 3 in the separation process was also confirmed to increase the zinc recovery in the solution while maintaining high Pb2+ removal efficiency. Image 103249 • Simple ball milling enabled CaCO 3 to react with Pb2+, but not Zn2+ in the solution. • The reaction resulted in the transformation of CaCO 3 into PbCO 3. • Over 99% Pb2+ precipitated and over 99% Zn2+ remained in the solution. • Efficient Pb removal was also possible from other solutions of Mn, Ni, Cd, etc. [ABSTRACT FROM AUTHOR]

Waterborne coatings are widely used for environmental protection. However, they lead to many defects and lower the mechanical properties when applied to wood surfaces. To address this challenge, the effects of multilayer waterborne polycrylic coatings on the mechanical properties of southern pine cell walls were investigated by nanoindentation. The experimental results indicated that the coating layers significantly reduced the elastic modulus (Er) and hardness (H) values than the wood cell walls. The Er and H values measured along the coating layer thickness direction increased significantly as the distance of the indents to the wood surface decreased. Intact cell walls adjacent to or away from the coating layers had higher Er and H values than partial ones. This study will also be useful in helping to understand the bonding mechanism at the interface between coatings and wood cell walls. [ABSTRACT FROM AUTHOR]

In this work, polyethylene glycol (PEG) and tributyl citrate (TBC) are proposed to modify the properties of wood fiber (WF, 20 wt%)‐reinforced polylactide (PLA, 80 wt%) biocomposites. The reinforcing and toughening effects of these additives were systematically investigated by comparing their mechanical, thermal and rheological properties. It was found that 5 wt% TBC improved the compatibility between WF and PLA and resulted in increased tensile strength (15%) and thermal stability (4%) of the biocomposites compared with those of unmodified biocomposites. The glass transition temperature, melting temperature, and crystallinity of TBC‐modified biocomposites were lower than those of PEG biocomposites. In addition, the storage modulus, loss modulus and complex viscosity of TBC‐modified biocomposites were effectively improved at low TBC content (5–10 wt%), whereas reduced properties were obtained when the same PEG content was added. As wettability is always a problem in biocomposites, the contact angle was not changed with TBC content (up to 20 wt%), and a linear decrease was observed with a PEG content up to 30 wt%. POLYM. COMPOS., 40:1384–1394, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

ABSTRACT: Cellulose nanocrystal (CNC) reinforced methacrylate (MA) resin nanocomposite was prepared by 3D stereolithography printing. A postcure process, where the printed nanocomposite was heat‐treated under different temperatures, was applied to improve the property of the printed nanocomposites. To investigate the effect of CNC and postcure temperature on the kinetic behavior of the postpolymerization of printed nanocomposites, Fourier‐transform infrared spectroscopy and differential scanning calorimetry measurement of the printed nanocomposites before and after postcure were analyzed. The postpolymerization of MA nanocomposites was promoted at a postcure temperature of 140 °C for the printed 0.5% CNC/MA nanocomposites compared to the printed MA resin. The addition of CNC retarded the polymerization of MA resin during 3D printing, resulting in poorer mechanical properties of the printed nanocomposites compared to the printed MA resin. However, after postcure, the mechanical properties of the printed nanocomposites were improved by the postpolymerization of the MA nanocomposites. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 935–946 [ABSTRACT FROM AUTHOR]

[Display omitted] • A new strategy to fabricate hydrochromic transparent wood biocomposite with responsive-humidity function. • The appearance color of the hydrochromic transparent wood biocomposite is switchable under different humidity conditions. • The hydrochromic transparent wood biocomposite is demonstrated in application of humidity and fingerprint detection. Stimulus-responsive materials with smart detection of humidity and moisture have been attracting extensive attention in wooden products, including the potential of developing the next generations of intelligent transparent wood. In this work, a hydrochromic transparent wood (HTW) biocomposite with characteristics of responsive to humidity is developed by compounding the oxazoline molecules with the transparent wood. The uniform distribution of oxazoline molecules in the cell wall of the transparent wood biocomposite is observed via the X-ray micro-computed tomography. The relationships of process-structure–property of the HTW are extensively characterized through confocal fluorescence microscopy and scanning electron microscopy. The resulting HTW biocomposite also possesses favorable thermal stability and mechanical properties. Moreover, the hydrochromic transparent wood can realize stable switching colors under different humidity conditions due to the reversible opening or closing of the oxazine rings. The fingerprint detection and various shapes on the surface of HTW biocomposite are demonstrated in the wet condition. This study provides a promising strategy to combine the detection of environmental humidity function and wooden bioresource that could be extended to broaden applications in smart buildings, intelligent sensors, simulative detectors, and anti-counterfeiting identifications. [ABSTRACT FROM AUTHOR]

Wood vinegar resulting from the pyrolysis of pruned elm tree branches contained a variety of organic compounds including acetic acid. Wood vinegar rapidly controlled broadleaf weeds in growth chamber and field experiments. [Display omitted] • Wood vinegar is produced from pyrolysis of urban pruning waste. • Wood vinegar contains a variety of organic compounds including acids. • Wood vinegar controlled multiple broadleaf weeds in fields. • Wood vinegar provided greater control of perilla mint at low than high temperatures. Pruning trees in urban landscapes produces a large amount of pruning waste. Pyrolysis is a process that thermally converts lignocellulosic biomass to a number of useful products, including wood vinegar. The objectives of this research were to 1) identify the composition and property of wood vinegar resulting from the pyrolysis of elm (Ulmus spp.) tree pruning waste and 2) evaluate the efficacy of wood vinegar for control of several broadleaf weed species. Acids along with various other chemical groups including alcohols, aldehydes, carbohydrates, phenols, nitrides, and ketones were identified in wood vinegar. Water constituted the highest proportion of wood vinegar, accounted for 77 % by weight. In growth chamber experiments, wood vinegar at 4000 L ha−1 showed 95 % injury and 76 % fresh aboveground biomass reduction of perilla mint [ Perilla frutescens (L.) Britt.] compared to the nontreated control at 7 d after treatment, whereas a 2000 L ha-1 application volume caused 80 % injury, with 60 % biomass reduction. The efficacy of 1000 or 2000 L ha−1 application volume were significantly lower. In field experiments, wood vinegar showed varying levels of control for perilla mint, creeping woodsorrel (Oxalis corniculata L.), and Carolina geranium (Geranium carolinianum L.). While wood vinegar at 4000 L ha-1 provided 100 % control of perilla mint and control of creeping woodsorrel and Carolina geranium were 82 % at best. Further, faster and greater control was achieved at low temperatures (10 °C) compared with high temperature conditions (20 or 30 °C). Overall, these findings suggest that wood vinegar derived from the pyrolysis of pruning waste can be used as a non-synthetic herbicide for control of broadleaf weeds. [ABSTRACT FROM AUTHOR]