A novel self-curing epoxy resin was synthesized using bio-oil. Bio-oil was produced by hydrothermal liquefaction of loblolly pine and utilized as a biopolyol in the synthesis of bio-oil-based epoxy resin (BOBER) for the first time. Hydroxyl groups in bio-oil were analyzed by quantitative 31 P NMR. It was found that not only does the total hydroxyl number of bio-oil influence the yield and epoxy equivalent weight of BOBER, but also the distribution of hydroxyl groups within bio-oil (aliphatic, phenolic, and acidic OH) played an important role in the determination of the optimum amount of catalyst in the synthesis of BOBER. Differential scanning calorimetry analysis proved the self-curing phenomena of BOBER, and Fourier transform infrared spectroscopy suggested that etherification reaction was the dominate reaction during the self-curing. Glass transition temperature, cross-linking density, and the storage modulus of self-cured BOBER were calculated using a dynamic mechanical analyzer.

Electroactive polymers that exhibit controlled deformation under an applied electric field, either in liquid or air, have great potential as soft robotic actuators. However, materials for soft robotics currently face challenges, including slow response, high actuation potential, and a lack of underlying mechanistic understanding. Additionally, fabrication of soft robotic actuators with complex design features has historically been restricted by two-dimensional fabrication methods. In this work, we investigate cross-linked poly­(acrylic acid)-based actuators prepared utilizing digital light projection (DLP), an additive manufacturing technique that enables fabrication of actuators with complex geometries. A series of photopolymerizable inks are prepared incorporating acrylic acid (monomer), trimethylolpropane trimethacrylate (cross-linker), and phenylbis­(2,4,6-trimethylbenzoyl)­phosphine oxide (photoinitiator). Soft actuators are 3D-printed utilizing a commercial DLP 3D printer operating under 405 nm UV light. These 3D-printed actuators exhibit large deformation (up to 43°), high actuation speed (up to 1.08°/s), and stable actuation performance for bending cycles under relatively low actuation voltage (4–6 V). Factors such as acrylic acid content, cross-linker concentration, actuator thicknesses, and electric field strength are varied, and their impact on the 3D-printed actuators are evaluated and discussed. Lastly, a membrane valve actuator is fabricated, and its ability to open and close under applied potential is demonstrated.

Lignocellulosic biomass is a sustainable alternative to petroleum-derived chemicals to develop biobased wood adhesives, which motivates integrated biorefineries to effectively convert biomass feedstock into desirable chemicals. Herein, lignin recovered from kraft biorefinery (L-KB) and two bio-oils, prepared from laboratory-scale solvent liquefaction of lignin (BO-SL/L) and fast pyrolysis of pinewood (BO-FP/PW), respectively, have been used to substitute 50% (w/w) of phenol in a novolac phenol−formaldehyde (NPF) resin system. The molecular structures of the L-KB, BO-SL/L, and BO-FP/ PW were characterized via FTIR, 13 C− 1 H HSQC 2D-NMR, GCMS, and carbohydrate analysis. Characterization results revealed the presence of functional moieties derived from lignin and polysaccharides. Further, the obtained resin adhesive structures were examined by FTIR and 1 H NMR spectroscopy, which confirmed the formation of methylene bridges during the resin preparation. Subsequently, to understand the curing behavior of each of the NPF resins with hexamethylenetetramine (HMTA) curing agent, DSC analysis was performed, which helped to optimize the bonding process. The resulting bonding strength of each resin adhesive, measured by gluing two pieces of wood, indicated significantly different adhesion ability due to structural differences, which was analyzed by twoway ANOVA, followed by Tukey's post hoc test. The 50-NPF-L-KB adhesive demonstrated a tensile shear strength of 3.46 ± 0.55 MPa, higher than the values of other tested adhesives. This indicates that the lignin derived from kraft biorefinery is a potential substitute for phenol in the NPF resin system for use in wood adhesive applications.

To prepare antibacterial, polymeric catheters for preventing catheter‐induced infections, sulfathiazole was loaded into polyurethane by solubilizing with solvents and the resultant films were cast. Fourier transform infrared spectroscopy confirmed the presence of sulfathiazole in the drug‐loaded polyurethane films. The thermal and mechanical properties of the films were assessed using differential scanning calorimetry and dynamic mechanical analysis. The drug‐loaded films were immersed in constantly stirred, deionized water at 37 °C for in vitro drug release study. The experimental data obtained from the in vitro drug release study were fit into mathematical models. Antibacterial efficiency of released sulfathiazole was evaluated by Escherichia coli growth inhibition test. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46467.