Coal drying by coke-oven gas at Sanmin Iron and Steel Works

The drying of coking batch by means of the secondary fuels in coke production is considered. OAO VUKhIN equipment for drying coal by means of flue gases from coke batteries has been installed at Sanmin Iron and Steel Works (China); its characteristics are described. Its use has reduced the moisture content of the batch by 3% (from 14 to 11%), with wet-coal charging at 200–250 t/h.     

Design,Synthesis, and Characterization of Macrocyclic Inhibitors of the Proprotein Convertase Furin

The activation of viral glycoproteins by the host protease furin is an essential step in the replication of numerous pathogenic viruses. Thus, effective inhibitors of furin could serve as broad-spectrum antiviral drugs. A crystal structure of an inhibitory hexapeptide derivative in complex with furin served as template for the rational design of various types of new cyclic inhibitors. Most of the prepared derivatives are relatively potent furin inhibitors with inhibition constants in the low nanomolar or even sub-nanomolar range. For seven derivatives the crystal structures in complex with furin could be determined. In three complexes, electron density was found for the entire inhibitor. In the other cases the structures could be determined only for the P6/P5-P1 segments, which directly interact with furin. The cyclic derivatives together with two non-cyclic reference compounds were tested as inhibitors of the proteolytic activation and replication of respiratory syncytial virus in cells. Significant antiviral activity was found for both linear reference inhibitors, whereas a negligible efficacy was determined for the cyclic derivatives.     

Design of 2-hydroxyethyl methacrylate-functional macromonomer dispersants by semi-batch cobalt chain transfer polymerization

Acrylic resins for automotive coatings are produced in nonaqueous dispersions (NAD) of nanometer size. These must be sterically stabilized by oligomeric dispersants, which are complex reactive oligomers possessing vinyl and hydroxyl functionalities, controlling the size of the nanocolloid. Hence, we have developed a kinetic Monte Carlo (kMC) model to improve the molecular structure of 2-hydroxyethyl methacrylate-functionalized poly (butyl methacrylate) (pBMA) dispersants of ca. 6,000 g/mol produced via semi-batch cobalt chain transfer polymerization (CCTP). The kMC-predicted degree of functionalization is benchmarked against a novel analytic expression suitable for oligomers. Stepwise adjustment of the semi-batch feed program illustrates the successive improvement in molecular structure of the dispersant product, finally arriving at a functionalization degree close to the theoretical maximum for CCTP.     

Self-assembled poly(ethylene glycol) methyl ether-grafted gelatin nanogels for efficient delivery of curcumin in cancer treatment

Curcumin (CUR) is a natural active ingredient that attracted much attention for its chemotherapeutic activity against tumors without causing toxicity in healthy cells. However, it has certain limitations for being used in chemotherapy such as low aqueous solubility and hydrolytic instability in the physiological environment. In this study, self-assembled poly(ethylene glycol) methyl ether-grafted gelatin (Gel-mPEG) nanogels were fabricated as delivery systems to improve the applicability of CUR in cancer treatment. CUR-loaded Gel-mPEG nanogels exhibited desired size range, relatively colloidal stability, and provided enhanced CUR stability in aqueous solutions. Especially, they showed significant high CUR loading capacity and better anticancer activity than free CUR as compared to previously reported CUR-loaded nanogels according to the best of our knowledge. Moreover, the in vitro release of CUR from the nanogels was controlled and prolonged up to 96 h. These results demonstrated that Gel-mPEG nanogels are the promising modality for the efficient delivery of CUR in cancer treatment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47544.     

Mechanical properties of continuous bamboo fiber-reinforced biobased polyamide 11 composites

This study is devoted to the analysis of the properties of continuous bamboo fiber (BF)-reinforced polyamide 11 (PA 11) composites. The SEM observations highlighted continuity between BFs and the polymeric matrix showing a high density of hydrogen bonds. The comparative calorimetric study of the matrix and its composites showed that the crystallinity of PA 11 was not modified by the presence of bamboo fibers. The physical aging observed in PA 11 is no more observed in composites due to physical interactions between PA 11 and BFs. The mechanical properties were investigated by tensile strength and dynamic mechanical analysis. The introduction of BFs enhanced Young's modulus of the matrix by a factor of 10. The presence of BFs also improved the storage shear modulus G′ over the whole temperature range. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47623.     

Interactive Multi‐objective Dynamic Optimization of Bioreactors under Parametric Uncertainty

Model‐based optimization techniques play a key role in achieving a sustainable operation of biochemical processes. Models are an approximation of the real process under study, hence, uncertainty is inherently present and for a sustainable process operation this uncertainty should be accounted for. In practice, optimality with respect to different conflicting objectives is required and multi‐objective optimization is a valuable tool. In this article the sigma point approach is applied to account for parametric uncertainty in the frame of interactive multi‐objective bioprocess optimization.     

Specific influence of polyethersulfone functionalization on the delamination toughness of modified carbon fiber reinforced polymer processed by resin transfer molding

The specific influence of polyethersulfone (PES) end‐functionalization with chlorine or hydroxyl end groups at same molar mass on PES‐epoxy composites based on a high‐performance tetra‐epoxide with di‐amine hardener resin (RTM6) is investigated in terms of morphology, thermal behavior, and toughness. A model study on PES filaments embedded in epoxy precursor is first performed to compare the interdiffusion and resulting morphology upon curing. PES‐OH shows a larger interdiffusion distance compared to PES‐Cl in the model systems and the laminates. This effect is more pronounced at high heating rate. Cross sections and fracture surfaces of composite panels are analyzed by scanning electron microscopy (SEM) coupled with energy dispersive X‐ray (EDX) spectroscopy to establish the link between the microstructures and fracture mechanisms. The toughness of PES‐OH‐modified epoxy composites is doubled compared to unmodified reference panels, whereas the PES‐Cl shows no improvement. The favorable influence of PES‐OH is ascribed to enhanced miscibility, interfacial adhesion and morphology, resulting from the better affinity between hydroxyl‐terminated PES and the epoxy‐resin. POLYM. ENG. SCI., 59:996–1009, 2019. © 2019 Society of Plastics Engineers     

Morphology-dependent spin Seebeck effect in yttrium iron garnet thin films prepared by metal-organic decomposition

In this study, we examined the dependence of surface morphology and spin Seebeck effect (SSE) voltages on the poly[vinylpyrrolidone] (PVP) concentration in polycrystalline Y₃Fe₅O₁₂ (YIG) ultrathin films on a silicon substrate synthesized by metal-organic decomposition followed by a crystallization process. During fabrication, PVP concentrations of 0.5–2 g were used while all other conditions remained fixed. Atomic force microscopy and grazing incidence X-ray diffraction (XRD) measurements revealed a strong dependence of crystallinity and sample morphology on PVP concentration. The 1-g PVP sample had the smoothest surface, with a root mean square roughness of 0.2 nm, as well as superior bulk uniformity with respect to the shape and intensity of XRD reflection peaks. This was confirmed by scanning electron microscopy measurements of a cross-section of the sample that revealed a uniform film without pores. SSE measurements were performed to obtain the output SSE voltages (V_SSE) of all samples, to which a platinum layer was added as a spin-detection layer. Repeatedly, the 1-g PVP sample had the best performance, demonstrating the importance of film crystallinity and morphology in the spin-to-charge conversion efficiency of YIG films.     

Reaction kinetics modeling and thermal properties of epoxy–amines as measured by modulated‐temperature DSC. II. Network‐forming DGEBA + MDA

Reaction‐induced vitrification takes place in the network‐forming epoxy–amine system diglycidyl ether of bisphenol A (DGEBA) + methylenedianiline (MDA) when the glass‐transition temperature (T_g) rises above the cure temperature (T_cure). This chemorheological transition results in diffusion‐controlled reaction and can be followed simultaneously with the reaction rate in modulated‐temperature DSC (MTDSC). To predict the effect of T_cure and the NH/epoxy molar mixing ratio (r) on the reaction rate in chemically controlled conditions, a mechanistic approach was used based on the nonreversing heat flow and heat capacity MTDSC signals, in which the reaction steps of primary (E_1OH = 44 kJ mol^?1) and secondary amine (E_2OH = 48 kJ mol^?1) with the epoxy–hydroxyl complex predominating. The diffusion factor DF as defined by the Rabinowitch approach expresses whether the chemical reaction rate or the diffusion rate determines the overall reaction rate. A model based on the free volume theory together with an Arrhenius temperature dependency was used to calculate the diffusion rate constant in DF as a function of conversion (x) and T_cure. The relation between x, r, and T_g, needed in this model, can be predicted with the Couchman equation. An experimental approximation for DF is the mobility factor DF* obtained from the heat capacity signal at a modulation frequency of 1/60 Hz, normalized for the effect of the reaction heat capacity in the liquid state and the change in C_p in the glassy region with x and T_cure. In this way, an optimized set of diffusion parameters was obtained that, together with the optimized kinetic parameters set, can predict the reaction rate for different cure schedules and for stoichiometric and off‐stoichiometric mixtures. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2814–2833, 2004     

Effect of butyl rubber type on properties of polyamide and butyl rubber blends

Polyamide‐12 was blended with butyl rubber, bromobutyl rubber, and chlorobutyl rubber with and without a sulfur curing system. Mechanical properties for dynamically vulcanized blends generally exceed those made with no vulcanization. Chlorobutyl‐containing blends prepared by dynamic vulcanization have higher tensile strength and elongation at break values in comparison to those made from other butyl rubbers. For a variety of polyamide/rubber blends made by dynamic vulcanization, there is very little effect of rubber percentage unsaturation and Mooney viscosity on the mechanical properties of the blends. In chlorobutyl‐containing blends prepared by dynamic vulcanization, the swelling index values attributed to the rubber portion decrease as rubber content decreases, and it is likely that the polyamide phase completely surrounds the rubber particles at compositions exceeding approximately 25% polyamide. Swelling index results can be correlated with elongation at break values for similar blends. The results of differential scanning calorimetry suggest that the polyamide phase is not a neutral component in high shear mixing with butyl rubbers with or without curing agents. Rheological studies indicate strong non‐Newtonian behavior for all blends of polyamide‐12 with butyl rubbers. Scanning electron microscopy on polyamide‐12/butyl rubber blends indicates compatibility for butyl rubbers in the order of chlorobutyl > bromobutyl > butyl rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1423–1435, 2004