Physical and mechanical properties of plasticized butenediol vinyl alcohol copolymer/thermoplastic starch blend

The poly(vinyl alcohol) (PVOH) is an eco‐friend polymer and has an excellent oxygen barrier property due to its strong intermolecular force, but difficulty in processing with conventional extrusion process gives it a limitation for various industrial applications, especially packaging industry. Many studies have attempted to plasticize PVOH to improve its processability, but high cost of PVOH is still drawback for a variety of industrial applications. Therefore, PVOH often blended with other biodegradable polymers such as starch to acquire the cost benefit. Nowadays, the butenediol vinyl alcohol copolymer (BVOH) is getting a great attention due to its melt processability and bio‐degradability, but its high cost is barrier to the industrial application as well. In this study, thermoplastic starch (TPS)/plasticized BVOH (P‐BVOH) were prepared by melt mixing technique, and the plasticization effect of glycerol on starch and BVOH with different composition was observed for optimized processing condition. Based on our preliminary study, TPS was blended with varying amount of P‐BVOH (100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 weight ratio). Physical, oxygen barrier, and mechanical properties of the TPS/P‐BVOH blends were evaluated by various analytical instruments to achieve balanced property and performance. J. VINYL ADDIT. TECHNOL., 25:109–116, 2019. © 2018 Society of Plastics Engineers     

Selective Coating of SnS on the Bio‐Inspired Moth‐Eye Patterned PEDOT:PSS Polymer Films

A new strategy for the selective coating of tin sulfide (SnS) on the surface of moth‐eye patterned (MEP) conducting polymer film is studied by considering the optical properties of the antireflective moth‐eye pattern and flexibility of polymer films. The semiconductor SnS is selectively coated on the surface of MEP microdomes of poly(3,4‐ethylenedioxythiophene) poly(styrene‐sulfonate) (PEDOT:PSS) film. The SnS coated MEP film is obtained by using pore selectively SnS thin layer functionalized polystyrene honeycomb‐patterned porous (HCP) film as a template. Aqueous PEDOT:PSS solution is poured on the SnS functionalized HCP films and detached for the fabrication of SnS coated MEP films. The films show a satisfactory photo‐responsive property under solar stimulated light illumination due to the antireflective MEP structure of PEDOT film and homogenous SnS coating on the surface of the conducting polymer.     

Determination of optimum fermentation conditions for carotenoid production by Rhodotorula aurantiaca K-505

Carotenoid production by Rhodotorula aurantiaca K-505 was optimized in shake-flask cultures using a central composite design. Quadratic polynomial models were used to correlate the relationships between six fermentation factors (pH, temperature, and the concentrations of glucose, yeast extract, peptone extract, and ammonium sulfate) and three response variables (cell mass yield, carotenoid content, and carotenoid production). Different optimum culture conditions were predicted by the models for maximizing the three response variables, indicating that there is no direct correlation between cell growth and carotenoid production. The maximum carotenoid production of 4.9 mg/L predicted by the relevant model under optimum culture conditions agreed well with the experimentally measured value of 5.3 mg/L under the same culture conditions.     

Transesterification of sunflower oil in a countercurrent trickle-bed reactor packed with a CaO catalyst

Transesterification of sunflower oil with methanol to form biodiesel was performed in a countercurrent trickle-bed reactor, using calcium oxide particles 1-2 mm in diameter as a packed, solid base catalyst. Although biodiesel production generally requires a reaction temperature below the boiling point of methanol to maintain a heterogeneous, liquid-liquid reaction, in the present study the reaction temperature was varied from 80 to 140 °C to confirm the progress of transesterification in a gas-liquid-solid phase reaction system. Oil droplets released from a thin tube flowed downward, while vaporized methanol flowed upward in the bed. The effects of the reaction temperature, methanol and oil flow rates, and the bed height on the FAME yield were investigated. The oil residence time in the reactor, which was controlled by changing both the oil flow rate and the bed height, had a significant effect on the FAME yield. In addition, the FAME yield increased with reaction temperature and was maximal at 373 K due to the change in residence time associated with reduced oil viscosity at higher temperatures. The FAME yield was 98% at a reaction temperature of 373 K when the methanol and oil flow rates were 3.8 and 4.1 mL/h, respectively.     

Identification and Field Evaluation of the Sex Pheromone of <Emphasis Type="Italic">Synanthedon bicingulata</Emphasis> (Staudinger)

The sex pheromone of Synanthedon bicingulata (Staudinger), a major pest of Prunus species in many regions of northeast Asia, was identified. Two major components from the pheromone gland extracts of female moths are (E,Z)-3,13-octadecadienyl acetate (E3,Z13-18:OAc) and (Z,Z)-3,13-octadecadienyl acetate (Z3,Z13-18:OAc), and the average ratio of these components is about 4:6, respectively. In addition to the major components, four minor components, (Z)-13-octadecenyl acetate (Z13-18:OAc), (E,Z)-2,13-octadecadienyl acetate (E2,Z13-18:OAc), (E,Z)-3,13-octadecadien-1-ol (E3,Z13-18:OH), and (Z,Z)-3,13-octadecadien-1-ol (Z3,Z13-18:OH) also were identified from pheromone gland extracts. Field tests showed that E3,Z13-18:OAc and Z3,Z13-18:OAc are essential for attraction of male S. bicingulata moths, and males are optimally attracted to the blend ratio found in pheromone gland extracts of conspecific females. Addition of the minor glandular components (Z13-18:OAc, E2,Z13-18:OAc, E3,Z13-18:OH, and Z3,Z13-18:OH) did not affect captures of males to the primary binary blend. Thus, the blend of E3,Z13-18:OAc and Z3,Z13-18:OAc at the natural ratio can be used for monitoring populations of this species.     

Physical properties of phenol-anchored multiwall carbon nanotube/epoxy nanocomposite

Surface functionalization of multiwall carbon nanotubes (MWCNTs) was carried out by introducing a ylide group containing anchored phenol structures. Epoxy nanocomposites filled with modified and pristine carbon nanotubes were prepared, and their mechanical, electrical, and thermal properties were evaluated. Mechanical properties such as tensile strengths and Young’s moduli of the epoxy nanocomposites increased significantly with the addition of the modified MWCNTs compared to the pristine MWCNTs, due to the strong interaction between the modified MWCNTs and the epoxy matrix. Scanning electron microscopy of the fractured epoxy systems revealed that the functionalized MWCNTs were finely dispersed in the matrix, as opposed to the pristine carbon nanotubes. The epoxy/functionalized MWCNT nanocomposite had a lower surface electrical resistance than the epoxy/pristine MWCNT nanocomposite, confirming the effect of functionalization.     

Effects of TS-1 zeolite structures on physical properties and enzymatic degradation of Poly (butylene succinate) (PBS)/TS-1 zeolite hybrid composites

The objective of this study was to investigate how the water uptake features and carrier characteristics of the TS-1 zeolite affected the physical and rheological properties, morphological parameters, and enzymatic hydrolysis of Poly (butylene succinate) (PBS). The introduction of TS-1 zeolite as catalyst was developed for the preparation of PBS/TS-1 zeolite hybrid composites (PTHC) without heavy metal toxic substance in the context on clean technology. The TS-1 zeolite can act as a catalyst as well as a reinforcement filler with the result that PTHC can show marked increases in tensile properties and elongation at breakage in the solid state. The rheological properties of PTHC with high zeolite contents showed low values of complex viscosity, as compared with PTHC with low TS-1 zeolite contents, due to the volatilization of water released from the zeolite pores during esterification. The introduction of the TS-1 zeolite in the PBS matrix was not significantly affected by changes in the size of the long period, lamella thickness, or the amorphous region, indicating that PBS chains do not penetrate into zeolite pores, as confirmed by SAXS profiles. In enzymatic hydrolysis over 90 days, the enzymatic hydrolysis rates of PTHC significantly accelerated with increasing TS-1 zeolite contents, compared with Homo PBS. This result indicated that TS-1 zeolite can act as a carrier for enzyme activation, resulting in enzymatic hydrolysis, occurring from the amorphous area on the surface into the inside of the film.     

Effect of the amount of reducing agent on surface structures, electrochemical activity and stability of PtRu catalysts

The effect of the amount of reducing agent used in the synthesis of PtRu alloy catalysts on their surface structure was investigated, and the prepared catalysts were characterized using transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry, and potential cycling. The alloying degree of the catalysts was essentially the same for all of the catalysts studied, despite the use of different amounts of reducing agent. Varying the amount of reducing agent resulted in changes in the surface composition of the catalysts, wherein the surfaces were found to be composed of several PtRu domains that differed in local inhomogeneity and hence showed differences in activity for CO_ad oxidation. The highest activity for methanol oxidation was obtained when there was moderate Ru enrichment of the catalyst. The electrochemical stability of the catalysts was also investigated via potential cycling in a methanol-containing electrolyte solution. The electrochemical stability under methanol oxidation was enhanced by Ru-enrichment at the catalyst surface, because the Ru-rich surface had sufficient Ru atoms near the Pt atoms to act as a bifunctional catalyst, even though the Ru atoms were leached out by potential cycling. The most Ru-rich catalyst exhibited an increase in methanol oxidation current in the middle of potential cycling whereas the other catalysts showed a monotonic decrease.     

Amorphous silicon–carbon based nano-scale thin film anode materials for lithium ion batteries

The buffering effect of carbon on the structural stability of amorphous silicon films, used as an anode for lithium ion rechargeable batteries, has been studied during long term discharge/charge cycles. To this extent, the electrochemical performance of a prototype material consisting of amorphous Si thin film (∼250 nm) deposited by radio frequency magnetron sputtering on amorphous carbon (∼50 nm) thin films, denoted as a-C/Si, has been investigated. In comparison to pure amorphous Si thin film (a-Si) which shows a rapid fade in capacity after 30 cycles, the a-C/Si exhibits excellent capacity retention displaying ∼0.03% fade in capacity up to 50 cycles and ∼0.2% after 50 cycles when cycled at a rate of 100 μA/cm² (∼C/2) suggesting that the presence of thin amorphous C layer deposited between the Cu substrate and a-Si acts as a buffer layer facilitating the release of the volume induced stresses exhibited by pure a-Si during the charge/discharge cycles. This structural integrity combined with microstructural stability of the a-C/Si thin film during the alloying/dealloying process with lithium has been confirmed by scanning electron microscopy (SEM) analysis. The buffering capacity of the thin amorphous carbon layer lends credence to its use as the likely compliant matrix to curtail the volume expansion related cracking of silicon validating its choice as the matrix for bulk and thin film battery systems.