Discoloration of green PET bottles recycled with chemical agents by reactive extrusion

This study evaluates the effect of incorporating chemical agents with green polyethylene terephthalate (PET) bottles on extrudate color change and other properties. First, the best type of chemical agent that decolorizes recycled green PET bottles (RGPB) with good processability was determined. RGPB-chemical agent mixtures were evaluated, reducing, photoinitiator, or oxidant, where the best one turned out to be the oxidizing agent, a dicumyl peroxide. Then new mixtures of RGPB-oxidizing agent, dicumyl or benzoyl, were made in a reactive extrusion process employing a drying hopper to avoid hydrolytic degradation. The intrinsic viscosity, crystallinity, and color change of extrudates were determined. It was determined by SEM with EDS that the dye is possibly a chlorinated copper phthalocyanine. The final results show an increase in the intrinsic viscosity of the PET handling dicumyl peroxide, a partial whitening of the extrudates, and an increase in the crystallinity of the PET, which contributed to a decrease the hue and saturation of the green color of RGPB. Where the dicumyl peroxide present in mixtures with RGPB interacts with chlorinated copper phthalocyanine to produce phthalamide or phthalic acid, which are white.

Download Full-text

Single Cell Based Microelectrode Array Biosensors

MRS Proceedings ◽

10.1557/proc-773-n11.6 ◽

2003 ◽

Vol 773 ◽

Author(s):

Mo Yang ◽

Shalini Prasad ◽

Xuan Zhang ◽

Mihrimah Ozkan ◽

Cengiz S. Ozkan

Keyword(s):

Electrical Activity ◽

Single Cell ◽

Cellular Response ◽

Microelectrode Array ◽

Fast Fourier Transformation ◽

Chemical Agent ◽

Extracellular Potential ◽

Membrane Excitability ◽

Specific Chemical ◽

Chemical Agents

AbstractExtracellular potential is an important parameter which indicates the electrical activity of live cells. Membrane excitability in osteoblasts plays a key role in modulating the electrical activity in the presence of chemical agents. The complexity of cell signal makes interpretation of the cellular response to a chemical agent very difficult. By analyzing shifts in the signal power spectrum, it is possible to determine a frequency spectrum also known as Signature Pattern Vectors (SPV) specific to a chemical. It is also essential to characterize single cell sensitivity and response time for specific chemical agents for developing detect-to-warn biosensors. We used a 4x4 multiple Pt microelectrode array to spatially position single osteoblast cells, by using a gradient AC field. Fast Fourier Transformation (FFT) and Wavelet Transformation (WT) analyses were used to extract information pertaining to the frequency of firing from the extracellular potential.

Download Full-text

Transfer of Drugs and Other Chemicals Into Human Milk

PEDIATRICS ◽

10.1542/peds.84.5.924 ◽

1989 ◽

Vol 84 (5) ◽

pp. 924-936

Author(s):

Keyword(s):

Drug Therapy ◽

Human Milk ◽

Breast Feeding ◽

Drug Exposure ◽

Chemical Agent ◽

Blood Concentrations ◽

Lactating Women ◽

Chemical Agents ◽

New Information ◽

Oral Analgesia

Since the first publication of this statement, much new information has been published concerning the transfer of drugs and chemicals into human milk. This information, in addition to other research published before 1983, makes a revision of the previous statement necessary. In this revision, lists of the pharmacologic or chemical agents transferred into human milk and their possible effects on the infant or on lactation, if known, are provided (Tables 1 to 7). The fact that a pharmacologic or chemical agent does not appear in the Tables is not meant to imply that it is not transferred into human milk or that it does not have an effect on the infant but indicates that there are no reports in the literature. These tables should assist the physician in counseling a nursing mother regarding breast-feeding when the mother has a condition for which a drug is medically indicated. The following questions should be considered when prescribing drug therapy to lactating women. (1) Is the drug therapy really necessary? Consultation between the pediatrician and the mother's physician can be most useful. (2) Use the safest drug; for example, acetaminophen rather than aspirin for oral analgesia. (3) If there is a possibility that a drug may present a risk to the infant (eg, phenytoin, phenobarbital), consideration should be given to measurement of blood concentrations in the nursing infant. (4) Drug exposure to the nursing infant may be minimized by having the mother take the medication just after completing a breast-feeding and/or just before the infant has his or her lengthy sleep periods.

Download Full-text

Effect of Dicumyl Peroxide on a Poly(lactic acid) (PLA)/Poly(butylene succinate) (PBS)/Functionalized Chitosan-Based Nanobiocomposite for Packaging: A Reactive Extrusion Study

ACS Omega ◽

10.1021/acsomega.8b00907 ◽

2018 ◽

Vol 3 (10) ◽

pp. 13298-13312 ◽

Cited By ~ 11

Author(s):

Monika ◽

Akhilesh Kumar Pal ◽

Siddharth Mohan Bhasney ◽

Purabi Bhagabati ◽

Vimal Katiyar

Keyword(s):

Lactic Acid ◽

Reactive Extrusion ◽

Poly Lactic Acid ◽

Dicumyl Peroxide ◽

Butylene Succinate

Download Full-text

Development of Transparent Electrodes Using Graphene Nano-Ink and Post-Consumer PET Bottles for Electrochromic Application

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.744.463 ◽

2017 ◽

Vol 744 ◽

pp. 463-467 ◽

Cited By ~ 3

Author(s):

Achanai Buasri ◽

Duangamol Ongmali ◽

Pongsatorn Sriboonpeng ◽

Sarinee Prompanut ◽

Vorrada Loryuenyong

Keyword(s):

Indium Tin Oxide ◽

Color Change ◽

Transparent Conductive Oxide ◽

Electrochromic Device ◽

Smart Windows ◽

Pet Bottles ◽

Transparent Substrate ◽

Electrochromic Windows ◽

Small Change ◽

Pet Film

Electrochromism refers to the reversible change of color of thin films due to a small change in the voltage. This is important for smart windows and display applications. The color change takes place because of intercalation and deintercalation of ions, which is controlled by voltage applied between transparent conductive oxide (TCO) layers. In this research, the use of graphene nano-ink and post-consumer poly(ethylene terephthalate) (PET) bottles as the flexible electrochromic windows was reported. PET film was coated with graphene ink by spin coating method. The sheet resistance value of PET/graphene electrode was 19 W/sq. The polypyrrole (PPy) also was electroactive and had good adhesion towards transparent substrate. Our results primarily indicated that the novel PET/graphene/PPy/graphene/PET electrochromic device offered an optical modulation, in which the color of the device switched from the black color to the yellow color under the applied potential at ± 2.0 V. The graphene in the electrochromic device demonstrated a potential for replacing indium tin oxide (ITO) in flexible electrochromic windows.

Download Full-text

Study of Selectively Permeable Coatings to Textiles

MRS Proceedings ◽

10.1557/opl.2011.2 ◽

2011 ◽

Vol 1312 ◽

Cited By ~ 1

Author(s):

Joseph G. Sargent ◽

Jun S. Lee ◽

Emmanuelle Reynaud ◽

Michael D. Gilbert ◽

James M. Sloan

Keyword(s):

Electron Microscopy ◽

Industrial Applications ◽

Chemical Agent ◽

Coating Materials ◽

Water Permeation ◽

Chemical Agents ◽

Transmission Electron ◽

Coated Fabric ◽

Coating Uniformity ◽

Electron Microscopy Analysis

ABSTRACTBreathable barrier textiles for both chemical agent and moisture are being actively developed for military and industrial applications. An ideal approach is to coat textiles with a semi-permeable film that allows the transport of water while still serving as a barrier for chemical agents. Sulfonated poly (styrene-block-isobutylene-block-styrene) (SIBS) copolymer spontaneously phase separates upon drying from solution to produce a nanostructured film with the controlled barrier functionality for water permeation and repelling of chemical agents.The objective of this research is to investigate coating uniformity and phase morphology of SIBS coating materials fabricated by novel solvent combinations. Scanning electron microscopy analysis is used for the assessment of the coating uniformity as well as the level of adhesion between the polymer coating and fabric substrate. Transmission electron microscopy is used to characterize the phase separation morphology of the SIBS copolymer coating. The mechanical behavior of the coated fabric is determined through tensile and shear tests and is compared to the bare fabric behavior. The goal of this study is to relate the processing conditions of the final nanostructured block copolymer coated fabric produced on industrial scale.

Download Full-text

Investigation of the Thermal and Hydrolytic Degradation of Polylactide during Autoclave Foaming

Polymers ◽

10.3390/polym13162624 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2624

Author(s):

Julia Dreier ◽

Christian Brütting ◽

Holger Ruckdäschel ◽

Volker Altstädt ◽

Christian Bonten

Keyword(s):

Thermal Degradation ◽

Hydrolytic Degradation ◽

Reactive Extrusion ◽

Foaming Properties ◽

Twin Screw Extruder ◽

Degradation Behavior ◽

Screw Extruder ◽

Melt Strength ◽

Twin Screw ◽

Good Potential

Polylactide (PLA) is one of the most important bioplastics worldwide and thus represents a good potential substitute for bead foams made of the fossil-based Polystyrene (PS). However, foaming of PLA comes with a few challenges. One disadvantage of commercially available PLA is its low melt strength and elongation properties, which play an important role in foaming. As a polyester, PLA is also very sensitive to thermal and hydrolytic degradation. Possibilities to overcome these disadvantages can be found in literature, but improving the properties for foaming of PLA as well as the degradation behavior during foaming have not been investigated yet. In this study, reactive extrusion on a twin-screw extruder is used to modify PLA in order to increase the melt strength and to protect it against thermal degradation and hydrolysis. PLA foams are produced in an already known process from the literature and the influence of the modifiers on the properties is estimated. The results show that it is possible to enhance the foaming properties of PLA and to protect it against hydrolysis at the same time.

Download Full-text

Numerical Modeling of Munitions Liquid Agent With Solid Heel in the Metal Parts Furnace

2010 14th International Heat Transfer Conference, Volume 4 ◽

10.1115/ihtc14-22964 ◽

2010 ◽

Author(s):

Yunhan Zheng ◽

Alfred Webster ◽

Mike Vanoni

Keyword(s):

Numerical Model ◽

Operating Efficiency ◽

Chemical Agent ◽

Vaporization Rate ◽

Processing Conditions ◽

Metal Parts ◽

Chemical Agents ◽

Computational Fluid Dynamics Cfd ◽

Liquid Chemical ◽

Fill Level

The Metal Parts Furnace (MPF) is a custom-designed incinerator and has been successfully demonstrated for treatment of munitions containing chemical agents since the first full-scale prototype baseline incineration facility on Johnston Island in 1990. The development of a numerical model to predict peak vaporization rate and total vaporization time during processing can provide the ability to control operating parameters to minimize the potential for any upset conditions such as agent overload, and to ensure that appropriate processing conditions are chosen to achieve desired safety factors. The numerical model will also provide the capability to maximize operating efficiency and to help adjust conditions during processing of different agents and munitions configurations. The Continental Research and Engineering (CR&E) Peak Vaporization Rate (PVR) model was initially developed in 1988 for the MPF to provide munitions tray vaporization rates as a function of the MPF temperature and munitions fill level. The model was updated and calibrated to test data in 1994. The calibrated PVR model is suitable for munitions with varying quantities of liquid chemical agent; however, this model can only be used to predict the vaporization rate of the liquid chemical agent. In order to simulate the effect of the solidified agent found in the munitions, CR&E has developed a Computational Fluid Dynamics (CFD) model based the vaporization rate model to simulate heating, melting, and vaporization of liquid chemical agent mixed with a varying solid heel mass fraction.

Download Full-text

Gas Sensing Characteristics of ZnO-doped SnO2 Sensors for Simulants of the Chemical Agents

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.9 ◽

2005 ◽

Vol 486-487 ◽

pp. 9-12 ◽

Cited By ~ 6

Author(s):

Kwang-Hyun Yun ◽

Ky-Youl Yun ◽

Geon-Young Cha ◽

Bong Ho Lee ◽

Jae Chang Kim ◽

...

Keyword(s):

Gas Sensing ◽

Zinc Acetate Dihydrate ◽

Chemical Agent ◽

X Ray Diffraction ◽

Tin Chloride ◽

Chemical Agents ◽

Phase Development ◽

Semiconductor Gas Sensors ◽

Sensing Characteristics ◽

Glycol Methyl Ether

After the 9∙11 terrorism and America-Iraq war, apprehension of mass destruction weapons such as bio-chemical agents calls for much more sensitive sensors which can detect toxic gases. In this study, semiconductor gas sensors based on tin oxide were examined to detect chemical agent simulants: dimethyl-methyl-phosponate (DMMP), di(propylene glycol) methyl ether (DPGME), acetonitrile, and dichloromethane. DMMP((CH3O)3), DPGME(C7H16O3), acetonitrile(CH3CN), and dichloromethane(CH2Cl2) gases are the simulants of nerve agent-sarin, vesicant agent-HN(N(CH2CH2Cl)3), blood agent-AC(HCN), and choking agent-CG(COCl2) gases, repectively. The SnO2 powder was prepared by a coprecipitation method from the mixture of tin chloride and zinc acetate dihydrate. Zinc oxide was doped into SnO2 from 1 wt% to 4 wt% to improve its reliability and sensitivity. To fabricate a thick film, powders were made into paste with organic binder of ethyl cellulose and screen-printed on the alumina substrate. The phase development and morphology of ZnO-doped SnO2 film were investigated by XRD (X-ray diffraction analysis), BET (surface and pore size analyzer), and SEM (scanning electron microscope). The gas sensing characteristics for target gases were examined with a flow-type measurement system. The concentrations of simulants were controlled from 500 ppb to 1500 ppb, and working temperatures were regulated from 250 to 400 .

Download Full-text

Biorefinery of the Olive Tree—Production of Sugars from Enzymatic Hydrolysis of Olive Stone Pretreated by Alkaline Extrusion

Energies ◽

10.3390/en13174517 ◽

2020 ◽

Vol 13 (17) ◽

pp. 4517

Author(s):

Pablo Doménech ◽

Aleta Duque ◽

Isabel Higueras ◽

Raquel Iglesias ◽

Paloma Manzanares

Keyword(s):

Enzymatic Hydrolysis ◽

Olive Oil ◽

Dry Weight ◽

Olive Tree ◽

Reactive Extrusion ◽

Extraction Process ◽

Raw Material ◽

Chemical Agent ◽

Olive Stone ◽

Conversion Rates

This work addresses for the first time the study of olive stone (OS) biomass pretreatment by reactive extrusion technology using NaOH as the chemical agent. It is considered as a first step in the biological conversion process of the carbohydrates contained in the material into bio-based products. OS is a sub-product of the olive oil extraction process that could be used in a context of a multi-feedstock and multi-product biorefinery encompassing all residues generated around the olive oil production sector. OS biomass is pretreated in a twin-screw extruder at varying temperatures—100, 125 and 150 °C and NaOH/biomass ratios of 5% and 15% (dry weight basis), in order to estimate the effectiveness of the process to favour the release of sugars by enzymatic hydrolysis. The results show that alkaline extrusion is effective in increasing the sugar release from OS biomass compared to the raw material, being necessary to apply conditions of 15% NaOH/biomass ratio and 125 °C to attain the best carbohydrate conversion rates of 55.5% for cellulose and 57.7% for xylan in relation to the maximum theoretical achievable. Under these optimal conditions, 31.57 g of total sugars are obtained from 100 g of raw OS.

Download Full-text

Appropriate hydration period and chemical agent improve priming in brachiaria seeds

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632016v4638422 ◽

2016 ◽

Vol 46 (3) ◽

pp. 350-356 ◽

Cited By ~ 2

Author(s):

Thiago Barbosa Batista ◽

Flávio Ferreira da Silva Binotti ◽

Eliana Duarte Cardoso ◽

Edilson Costa ◽

Daniele Maria do Nascimento

Keyword(s):

Experimental Design ◽

Phase Ii ◽

Seedling Emergence ◽

Chemical Agent ◽

Chemical Agents ◽

Physiological Quality ◽

Urochloa Brizantha ◽

Carbohydrate Contents ◽

Direct Immersion ◽

Lower Period

ABSTRACT Priming is an alternative to improve the performance of seeds that have germination problems, such as Urochloa brizantha seeds. This study aimed at evaluating the appropriate hydration period and chemical agents used for priming, via direct immersion, in the physiological quality and carbohydrate content of U. brizantha seeds. The experimental design was completely randomized, in a 3 x 4 factorial arrangement, with four replicates of each treatment, consisting of lower, median and higher hydration periods, in the phase II of the absorption curve, and agents used for priming: water, gibberellin, sucrose and antioxidant (riboflavin). Germination and vigor tests were carried out, as well as carbohydrate contents determination, in the seeds. It was observed that seeds hydrated in the lower period show higher physiological potential. Priming with gibberellin provides a greater seedling emergence, and with sucrose higher carbohydrate contents.

Download Full-text