Assessing technologies for reducing dust emissions from sintermaking based on cross-media effects and economic analysis

Clean Technologies and Environmental Policy - The Industrial Emission Directive (IED) requires industrial establishments to apply the best available techniques (BATs), and competent environmental...     

Effects of halloysite nanotubes on the performance of plasticized poly(lactic acid)‐based composites

The objective of this study is processing and characterization of Halloysite nanotube (HNT)/poly(lactic acid) (PLA) nanocomposites. As HNT filler, a domestic source was used (ESAN HNT). The results obtained from this HNT were compared with a well‐known reference HNT (Nanoclay HNT). To achieve the desired physical properties and clay dispersion, composites were compounded via direct melt mixing in a laboratory twin‐screw compounder. However, the constituents were observed to be incompatible without a compatibilizer. To improve the flexibility of nanocomposites and provide compatibilization between PLA and HNT, two types of blends were prepared: PLA plasticized with poly(ethylene glycol) (PEG) denoted as P‐PLA and PLA toughened with a thermoplastic polyurethane (TPU) denoted as T‐PLA. Despite the limited improvement in the P‐PLA blends, TPU addition improved the flexibility of PLA/HNT without deteriorating the tensile strength in a great manner. This was attributed to the relatively better compatibilization effect of TPU and the role of nanotubes acting as bridges between the TPU and PLA phases. POLYM. COMPOS., 37:3134–3148, 2016. © 2015 Society of Plastics Engineers     

Effects of processing conditions on the fiber length distribution and mechanical properties of glass fiber reinforced nylon‐6

The effects of processing conditions on fiber length degradation were investigated in order to produce composites with higher performance. Nylon‐6 was compounded with glass fibers in a twin‐screw extruder for various combinations of screw speed and feed rate. Collected samples were injection molded and Izod impact and tensile tests were performed in order to observe the effect of fiber length on the mechanical properties. Also, by using the extruded and injection molded smaples, fiber length distribution curves were obtained for all the experimental runs. Results show that when the shear rate is increased through the alteration of the screw speed and/or the feed rate, the average fiber length decreases. Impact strength, tensile modulus and tensile strength increase, whereas elongation at break decreases with the average fiber length.     

A preliminary investigation of caramelisation and isomerisation of allulose at medium temperatures and alkaline pHs: a comparison study with other monosaccharides

Allulose, also known as rare sugar, is a very reactive monosaccharide in browning reactions. In this study, the caramelisation of allulose was investigated for the first time. To study caramelisation, sugar solutions (glucose, fructose and allulose) were prepared with distilled water and buffer solutions at pH 7, 10, 12 and were freeze-dried afterwards. To let caramelisation occur, samples were incubated at 55% relative humidity (RH) and 50 °C. Results showed that samples prepared with pH 10 and pH 12 buffer solutions resulted in a higher browning rate than samples prepared with distilled water (DW) and pH 7 buffer solution. Moreover, according to HPLC and total reducing sugar content results, allulose (Allu) samples had the lowest remaining reducing sugar (RRS) amount, indicating that Allu samples depleted more in the reaction. Overall, the approach followed in this study can be considered as a novel strategy to obtain allulose-containing caramel-like products more efficiently than conventional methods.     

Mechanical and rheological properties,and morphology of polyamide-6/organoclay/elastomer nanocomposites

The effects of ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer and three types of organoclays (Cloisite^® 15A, 25A, and 30B) on mechanical and rheological properties, and morphology of impact modified polyamide-6/montmorillonite ternary nanocomposites were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), parallel disk rheometry, melt flow index measurements, and tensile and impact tests. The materials were prepared by melt blending using a co-rotating twin-screw extruder. XRD and TEM analyses showed that exfoliated-intercalated nanocomposites were formed in both polyamide-6/Cloisite^® 25A and Cloisite^® 30B binary nanocomposites and in ternary systems. SEM micrographs showed that rubber domain sizes were larger in the nanocomposites than in their corresponding polyamide-6/elastomer blends. Generally, tensile strength, Young's modulus, and elongation at break decreased with the addition of elastomer to polyamide-6/organoclay binary nanocomposites. In the melt state, liquid-like behavior of polyamide-6 slightly turned to pseudo solid-like in the binary and ternary nanocomposites. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Improved predictions of alarm and safety system performance through process and operator response‐time modeling

Dynamic risk analysis (DRA) has been used widely to analyze the performance of alarm and safety interlock systems of manufacturing processes. Because the most critical alarm and safety interlock systems are rarely activated, little or no data from these systems are often available to apply purely‐statistical DRA methods. Moskowitz et al. (2015)¹ introduced a repeated‐simulation, process‐model‐based technique for constructing informed prior distributions, generating low‐variance posterior distributions for Bayesian analysis,¹ and making alarm‐performance predictions. This article presents a method of quantifying process model quality, which impacts prior and posterior distributions used in Bayesian Analysis. The method uses higher‐frequency alarm and process data to select the most relevant constitutive equations and assumptions. New data‐based probabilistic models that describe important special‐cause event occurrences and operators’ response‐times are proposed and validated with industrial plant data. These models can be used to improve estimates of failure probabilities for alarm and safety interlock systems. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3461–3472, 2016     

Synthesis and study of the oligo(ether–ester)s based on butylene oxide

Unsaturated oligo(ether–ester) was prepared by ring‐opening polymerization of butylene oxide (BO) with glycidyl methacrylate (GMA) in the presence of cationic catalyst BF₃^?O(C₂H₅)₂. The effects of mol ratio of the initial components, amount of catalyst, temperature, and reaction times on the copolymerization reaction were examined. Oligo(ether–ester) were achieved in highest yield of 82% after reaction times of 4 h at 0°C. Synthesized copolymer was characterized using spectroscopic (¹H NMR and IR) and chemical analysis methods. The thermal degradation and softing points of oligo(ether–ester)‐styrene composites were studied. It is shown that crosslinking of the unsaturated oligo(ether–ester) with styrene takes place through the use of thermostable materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.     

Relaxation time,activation energy,and reaction pathway determination of the poly(ethylene glycol dimethacrylate)–dopant (I2) interaction with the nuclear magnetic resonance technique

Conductive polymers were obtained with a new polymerization method in which UV light was used as a photochemical initiator. In a previous work, optimum irradiation times were determined to obtain high conversion percentages. The effect of dopants on the conductivity of the polymer poly(ethylene glycol dimethacrylate) (PEGDM) was studied with LiClO₄ and I₂ as a dopant. The most effective dopant concentration was determined by the measurement of conductivities. Through the tracing of the conductivity change at various temperatures during the reaction of PEGDM with the dopant, the activation energies of the interactions were calculated, and a method was developed to follow the kinetics of the polymerization reaction with a conductometric technique. This work presents a nuclear magnetic resonance (NMR) study of the same polymer prepared under the optimum conditions with the results obtained in a previous study. NMR spectroscopy was used to determine the relaxation time, rate constants, and activation energy of the polymer–dopant interactions. As a preliminary study, pyruvic acid was used, and for acid‐catalyzed pyruvic acid/water reactions, the relaxation time, activation energy, and enthalpy change values (ΔH) were determined. With the same NMR technique, the reaction mechanisms of the polymerization, relaxation times, and rate constants of the polymer–dopant interactions were determined. The polymerization pathway was determined with NMR spectra; the results were confirmed by the calculation of the activation energies and bond‐breaking energies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:5087–5101, 2006     

Poly(lactic acid)–layered silicate nanocomposites: The effects of modifier and compatibilizer on the morphology and mechanical properties

Poly(lactic acid) (PLA) based nanocomposites were prepared to investigate the effects of types of nanoclays. Five different organically modified nanoclays (Cloisites^®15A, 25A, and 30B, and Nanofils^®5 and 8) were used. Two rubbery compatibilizers, ethylene‐glycidyl methacrylate (E‐GMA) and ethylene‐butyl acrylate‐maleic anhydride, were used in the nanocomposites as compatibilizer‐impact modifier. The degree of clay dispersion, the chemical compatibility between the polymer matrix and the compatibilizers, and changes in the morphology and mechanical properties of the nanocomposites were investigated. The mechanical properties and the morphological studies showed that the interactions between the different compatibilizers and PLA resulted in different structures and properties; such that the dispersion of clay, droplet size of the compatibilizer, and tensile properties were distinctly dependent on the type of the compatibilizer. Compatibility between C25A, C30B, and E‐GMA resulted in the best level of dispersion, leading to the highest tensile modulus and toughness among the compositions studied. In the mentioned nanocomposites, a network structure was formed owing to the high reactivity of the epoxide group of GMA towards the PLA end groups resulting in high impact toughness. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42553.