Water-soluble Plastic Research Articles

Soft plastic fishing lures as a potential source of chemical pollution - Chemical analyses, toxicological relevance, and anglers’ perspectives

Soft plastic lures (SPLs) are commonly used artificial lures in recreational angling. Anglers regularly lose SPLs while fishing and there is little knowledge about the environmental impacts of lost SPLs. As with other plastic items, SPLs contain phthalates and other persistent additives that may leach into water. In this study, 16 randomly chosen SPLs of common models were analyzed for the leaching of persistent, water-soluble plastic additives, including phthalates. The estrogenicity of sample extracts from a subsample of 10 SPLs was assessed using luciferase reporter gene bioassays. Over a period of 61 days, 10 of the 16 SPLs leached the targeted phthalates dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP) and di-n-butyl phthalate (DnBP) at median detectable concentrations ranging from 10 ng/g sample BBP to a median of 1001 ng/g DMP as well as 45 persistent, mobile, and toxic (PMT) plastic additives. DEP was detected most frequently in 8 SPLs, followed by BBP (2 SPLs), DMP (2 SPLs) and DnBP (1 SPL). The extract from one SPL with comparatively low phthalate and PMT plastic additive levels was active in the bioassay, indicating high endocrine-disruptive potential, presumably due to unknown additives that were not among the target substances of the methodology used in this study. The study was supplemented by a mail survey among anglers, in which attitudes of anglers towards SPLs were investigated. The survey indicated that SPL loss is a common event during angling. Most participants were concerned about potential ecological impacts of SPLs, wanted the ingredients of SPLs to be labelled and supported legal restrictions concerning toxic ingredients of SPLs. The study shows that SPLs are a potential source of environmental pollution, may pose human health risks and need further investigation, considering the frequent use of SPLs in recreational angling.

Linear Strain Sensors via a Spatial Heteromodulus Tricontinuous Structure Design for High-Resolution Recording of Snoring Breath.

Porous conductive elastomer composites are very attractive for designing flexible and air-permeable mechanical sensors for healthcare, while it is challenging to achieve a linear and sensitive electromechanical response over a wide strain range for high-resolution recording of physiological activities and body motions. Here, a scalable strategy is developed to construct porous elastomer composites with a bamboo-shaped heteromodulus microstructure in the pores for the fabrication of linear stretchable strain sensors. Such a spatial heteromodulus microstructure is fabricated via phase separation and selective location of high-modulus phase during melt compounding of elastomers and thermoplastics, together with green etching of the water-soluble plastic in the tricontinuous elastomer composites. The bamboo-shaped heteromodulus microstructure is constructed on the pore struts via the fracture of a high-modulus polymer self-assembled on the pore surface and relaxation recovery of the elastomer matrix after prestretching, which blocks the propagation of cut-through microcracks upon stretching. The composites with super low resistance after in situ growth of silver nanoparticles sustain up to 110% tensile strain with a linear and sensitive electromechanical response, demonstrating potential applications in discriminating respiration status and monitoring snoring breath. This work unveils a new approach to fabricate high-performance air-permeable strain sensors in a simple and scalable way.

Preparation of blast furnace dust particle electrodes and their application in synergistic electrochemical degradation of saline polyvinyl alcohol wastewater

Polyvinyl alcohol (PVA) has been widely used as a water-soluble plastic in laundry and dish detergent pods, yet wastewater contaminated with PVA is too difficult to be treated due to its high salinity and foaming. Here, we fabricated blast furnace dust (BFD) particle electrodes, and developed a three-dimensional electrocatalytic system (3DEC) to treat saline PVA wastewater. The optimum preparation condition for BFD particle electrode was iron carbon ratio of 2:1 doping with TiO2. The optimal parameters of 3DECs for PVA wastewater degradation were thoroughly investigated, with current density of 30 mA/cm2, electrode distance of 30 mm, pH value of 7.0, and particle electrode filling rate of 50%. PVA wastewater degradation rate could reach 89.33% within 120 min. The underlying mechanism of iron-carbon micro electrolysis and electrocatalytic system was further studied. PVA wastewater was degraded by direct catalytic oxidation from electrodes. A scavenger experiment showed that free radicals consisting of •OH and HClO mainly contributed to the PVA wastewater degradation. HClO was generated by Cl− at the electrocatalysis and micro electrolysis of particles. In addition, the lifetime of the prepared BFD particle electrode was 120 h, which exhibited electrochemical stability. These findings highlight that the 3DECs coupled with BFD particle electrode is a promising electrocatalysis process for the removal of PVA wastewater.

Toxicity tests sought for plastic on detergent pods

A cleaning product company and environmental activists are asking the US Environmental Protection Agency to require health and safety tests on polyvinyl alcohol (PVA). This water-soluble plastic is widely used to encase pods containing concentrated laundry and dishwasher detergents . They are also petitioning the EPA to remove PVA from the Safer Choice program ’s list of chemicals that the agency considers safer for human health and the environment than ingredients with similar functional properties. The EPA should keep PVA off this list until manufacturers complete health and safety testing under the Toxic Substances Control Act (TSCA) , the petition says. The company filing the petition is Blueland, a cleaning product manufacturer that makes pressed-powder pods for home and personal care products. Blueland’s products directly compete with PVA-based ones. Joining Blueland in the filing is the nonprofit Plastic Pollution Coalition . Citing a paper published in 2021, the petitioners say

Water-soluble plastic as a medium to make polyester patchwork embroidery craft

This study aimed to describe the process of polyester fabric waste to be an alternative material to make interior textiles. The characteristics of polyester fabric waste meet the qualities needed to be used as the material for making interior textile. The problem in this study is the effectiveness of using water soluble film paper as a medium for the application of manual embroidery techniques to make polyester patchwork. This study used experimental and implementation methods on textile crafts. The results of this study show that water soluble film paper can be used as a medium for applying manual embroidery techniques on polyester patchwork which is profitable and does not leave any residual waste. Thus, this medium is considered environmentally friendly. This method can be applied to bring out the element of craftsmanship based on the scope of textile craft study. Functional products made by using this method are also expected to provide aesthetic value in a room. This study is essential and useful to contribute to an overview to the community about alternative resources for apparel industry waste from the local area that can be created into new products with higher value.

Degradation of Polyvinyl Alcohol in US Wastewater Treatment Plants and Subsequent Nationwide Emission Estimate.

Polyvinyl alcohol (PVA) is a water-soluble plastic commercially used in laundry and dish detergent pods (LDPs) for which a complete understanding of its fate in the environment and subsequent consequences is lacking. The objective of this study was to estimate the US nationwide emissions of PVA resulting from domestic use of LDPs, corroborated by a nationwide, online consumer survey and a literature review of its fate within conventional wastewater treatment plants (WWTPs). Peer-reviewed publications focusing on the degradation of PVA in critical processes of WWTPs were shortlisted as a part of the literature review, and subsequent degradation data was extracted and applied to a model with a set of assumptions. Survey and model results estimated that approximately 17,200 ± 5000 metric ton units per year (mtu/yr) of PVA are used from LDPs in the US, with 10,500 ± 3000 mtu/yr reaching WWTPs. Literature review data, when incorporated into our model, resulted in ~61% of PVA ending up in the environment via the sludge route and ~15.7% via the aqueous phase. PVA presence in the environment, regardless of its matrix, is a threat to the ecosystem due to the potential mobilization of heavy metals and other hydrophilic contaminants.

Research on Tension and Correction of Filming Steel Strip on Hydrosol Salivation Machine

The filming mechanism and producing process of water-soluble plastic film is introduced in this paper. The principle and application of tension and correction of filming steel strip on hydrosol salivation machine is discussed systemically.

A New Model with an Anatomically Accurate Human Renal Collecting System for Training in Fluoroscopy-Guided Percutaneous Nephrolithotomy Access

Obtaining renal access is one of the most important and complex steps in learning percutaneous nephrolithotomy (PCNL). Ideally, this skill should be practiced outside the operating room. There is a need for anatomically accurate and cheap models for simulated training. The objective was to develop a cost-effective, anatomically accurate, nonbiologic training model for simulated PCNL access under fluoroscopic guidance. Collecting systems from routine computed tomography urograms were extracted and reformatted using specialized software. These images were printed in a water-soluble plastic on a three-dimensional (3D) printer to create biomodels. These models were embedded in silicone and then the models were dissolved in water to leave a hollow collecting system within a silicone model. These PCNL models were filled with contrast medium and sealed. A layer of dense foam acted as a spacer to replicate the tissues between skin and kidney. 3D printed models of human collecting systems are a useful adjunct in planning PCNL access. The PCNL access training model is relatively low cost and reproduces the anatomy of the renal collecting system faithfully. A range of models reflecting the variety and complexity of human collecting systems can be reproduced. The fluoroscopic triangulation process needed to target the calix of choice can be practiced successfully in this model. This silicone PCNL training model accurately replicates the anatomic architecture and orientation of the human renal collecting system. It provides a safe, clean, and effective model for training in accurate fluoroscopy-guided PCNL access.

Quality Control in the Process of Drying Forming of Water-Soluble Plastic Film

We analyzed systematically the causes of various defects of water-soluble plastic film by the production process, and comprehensively discussed the corresponding treatments to reduce or eliminate the defects, to offer theoretical basis and practical methods to the quality control in the production of water-soluble plastic film.

Characterization of Kappa-Carrageenan-Based Water Soluble Plastic Film as a Potential Fruit Packaging

Conventional plastics manufactured from non-renewable fossil fuels contribute heavily to solid waste disposal. This study showed that the proper selection of enhancer added to the polysaccharide kappa-carrageenan (?C) can improve the properties of the resulting water soluble plastic film. This study is focused on the effect of three enhancers (glycerol, carbopol and boric acid) on the solubility, tensile strength and water vapor permeability of ?C-based film which may be used for fruit packaging. Through carboxymethylation process, ?C was modified with monochloroacetic acid (MCA) as the etherifying agent. Using ?C and carboxymethyl-kappa-carrageenan (CM?C) as the base polymers, three formulations containing increasing amount of enhancers were prepared. Fruit packaging properties were the basis for this experimentation. The resulting plastic films were soluble in water, and insoluble in 1.0 N HCl, 1 M NaOH, and seawater. In the mechanical tests (tensile strength measured by Universal testing Machine), the

Quantitative histofluorescence of hippocampal mossy fiber zinc

N-(6-methoxy-8-quinolyl)- p-toluenesulfonamide (TS-Q) is a fluorescent probe for histochemically detecting a chelatable pool of zinc in the hippocampal formation and other brain regions. Utilization of zinc:TS-Q histofluorescence as a quantitative tool required further characterization of zinc:TS-Q fluorescence and the development of appropriate zinc standards. Studies of zinc:TS-Q fluorescence in aqueous solutions were conducted to optimize the reaction conditions for TS-Q chelation with zinc. Possible interference of zinc:TS-Q fluorescence by chelation of other biologically significant cations with zinc:TS-Q was shown to be negligible. Zinc standards were developed using a water soluble plastic embedding medium. Varying the concentration of zinc in the plastic sections yielded a standard curve exhibiting a log-linear relationship between 0.15 and 11 fg zinc/100 μm 2. Zinc:TS-Q histofluorescence was characterized in horizontal sections of rat ventral hippocampal formation using a computerized image analysis system. Section thickness and TS-Q concentration were optimized. The concentration of zinc varied between 1.5 and 17 fg/100 μm 2 in different regions of the mossy fiber projection of the ventral hippocampal formation. The development of this quantitative histofluorescence technique should facilitate our understanding of the functional role of zinc in the mossy fiber projection and can be utilized to investigate changes in mossy fiber zinc in a variety of pathological states.

Experimental Methods for Studying Male Reproductive Function in Standard Toxicology Studies

Indicators of insult to the male reproductive system can be incorporated into standard toxicology studies so that the assessment of reproductive toxicity does not interfere with the general toxicologic evaluation. This can include assessment of testicular spermatids, or sperm from the epididymis, or vas deferens, or assessment of semen collected from the female reproductive tract postcoitally. Endpoints evaluated may include sperm count, motility, or sperm head morphology. Testicular morphology also may be evaluated by various improved histologic techniques. For example, when testes are immersion-fixed in formalin, testicular morphology is significantly improved by embedding the tissue in the water-soluble plastic glycol methacrylate (GMA) rather than paraffin. These approaches to male reproductive toxicology are cost-effective and reduce the number of animals required for pilot or survey studies for testicular toxicity. They can provide useful data on male reproductive function.

Ultrastructural features of the lymphocyte-stimulated halos produced by human glioma-derived cells in vitro

Many glioma-derived cell lines have the capability of escaping cell-mediated immune attack. One mechanism of escape is the secretion of a hyaluronidase-sensitive mucopolysaccharide coat by these cells. This coat prevents contact and tumor cell killing by specific cytolytic allogeneic lymphocytes. The production of the coat by the tumor cells is stimulated by a macromolecular factor released by peripheral blood mononuclear (PBMC) cells in culture. We have examined the morphologic and ultrastructural features of this extracellular matrix. Three coat-producing lines were studied. Under phase contrast light microscopy, the coat is a clear pericellular 'halo'. To stain this zone, ruthenium red and Alcian Blue 8 G stains, which bind to acid mucopolysaccharides (to a large extent, hyaluronic acid), were used. The two stains produced similar results. With light microscopy, a weblike pattern of stain was evident throughout the halo region. With transmission electron microscopy, staining was found along the plasma membrane of the glioma cells and their microvilli, stretching in long, branching filaments from these surfaces and, in some instances, from one microvillus to the next. Since mucopolysaccharide matrices have a large aqueous component, it was necessary to determine whether dehydration alters the stain pattern. Therefore, undehydrated ruthenium red stained specimens from each culture were embedded in Quetal 651 (Ted Pella, Inc., Tustin, CA), a water soluble plastic. No morphologic differences were noted between the hydrated and dehydrated specimens. This study indicates that numerous long microvilli and a secreted mucopolysaccharide matrix are important structural elements of the lymphocyte-stimulated tumor cell halo in vitro. The mechanism by which the PBMC factor stimulates coat formation and the importance of the coat in in vivo tumor defenses remain to be elucidated.

Immunocytochemical localization of water-soluble glycoproteins, including Group 1 allergen, in pollen of ryegrass,Lolium perenne, using ferritin-labelled antibody

The cellular sites of the glycoproteins Group 1 allergen (glycoprotein 1) and Antigen A (glycoprotein 2) in mature ryegrass pollen have been investigated by immunoelectron microscopy. Radioimmunoassays confirm previous findings of cross-reactivity between the purified glycoprotein antigens at the high immunoglobulin G (IgG) concentrations used for localization. Freeze-drying of anthers followed by anhydrous processing has been employed because of the water solubility and mobility of the glycoproteins. A double-embedding technique has been developed. This involves, first, embedding anthers in the water-soluble plastic resin JB-4, sectioning and incubating in ferritin-labelled antisera by the indirect method. The sections are then embedded in Spurr's resin for ultra-thin sectioning. Both glycoproteins are found in the following sites: (1) exine and intine wall layers; (2) pollen cytoplasm; (3) the orbicules and anther loculus; and (4) the anther cuticle. In the exine arcades and surface and in the anther loculus, the ferritin label is bound to pollenkitt. The finding that the glycoproteins are in similar sites is predictable in view of the cross-specificity of the antisera. The extent of antibody penetration of the plastic sections has been examined; labelling is confined to cut grains and absent from intact grains.

Embedment in glycol methacrylate at low temperature allows immunofluorescent localization of a labile tissue protein.

The antigenic activity of a labile protein postulated to the hormone ovine chorionic somatomammotropin (OcS) is preserved in tissue fixed in either glutaraldehyde or paraformaldehyde and low temperature-embedded in the water-soluble plastic glycol methacrylate. Immunofluorescence techniques used on 1--2 micrometer thick sections show that this protein is located in the cytoplasm of certain fetal chorionic cells in association with small spherical bodies, which may be lipid. The use of borohydrate reduction or treatment with Schiff's reagent to reduce glutaraldehyde-induced background fluorescence is described.

Postmortem Radiography of the Subarachnoid Cisterns

A technique has been developed for stereotactic postmortem cisternography using water-soluble contrast medium and plastic material with enhanced attenuation by the addition of red lead. The latter technique can be used for the preparation of plastic casts of the cisterns, accessible for analysis by radiologic means as well as by direct inspection.

Specificity of phosphotungstic acid used as a section stain to visualize surface coats of cells

Phosphotungstic acid (PTA) at low pH has been used as a section stain to visualize surface coats of ductal epithelial cells within human breast biopsies in the electron microscope. For this purpose, tissue was fixed in glutaraldehyde and embedded in the water-soluble plastic glycol methacrylate. Since there is some uncertainty regarding the chemical nature of material within embedded tissue that is stained by PTA under acidic conditions, cytochemical studies were performed. Sections were incubated with Pronase, trypsin, α-amylase, hyaluronidase, and neuraminidase and then stained with PTA. Sections were also exposed to reagents which are known either to remove most of the carbohydrate groups from glycoprotein or just terminal sialic acid residues. Results are compatible with the view that much of the staining of surface material by acidic PTA could be due to the presence of sialic acid residues within surface coat glycoprotein.

The Kinetic Evaluation for Photo-Oxidation of PVA (Polyvinyl Alcohol)

We previously reported the correlation of physical properties of plastics (ultimate strength and relative elongation at break) with changes of their internal structures during the ultraviolet ray deterioration from kinetic point of view.Hereunder presented is the report of kinetic studies about the oxidation of water soluble plastic, PVA (polyvinyl alcohol), under ultraviolet rays in the atmosphere of nitrogen and oxygen. The differences in the mechanisms of deterioration under the different conditions of surrounding gas were investigated by the infrared absorption method. At the same time, the crystallinity and stereospecific (syndiotactic diad) were determined from the ratio of absorbances of crystallization (1141cm-1) and stereospecific bands (916cm-1, 849cm-1).The results of these experiments are as follows:(1) The rate of increase or decrease in the absorption band for each functional group is a first order reaction.(2) The remarkable increase in the absorptions of carbonyl groups, such as esteric type (1738cm-1), aldehydic type (1720cm-1), ketonic type (1709cm-1) and acidic type (1700cm-1), are recognized and their quantities are in the order of ketonic, acidic, aldehydic and esteric in nitrogen atmosphere and of aldehydic, ketonic, acidic and esteric in oxygen.(3) The mechanism of the photo-oxidation is closely related with the mechanisms of formation of these carbonyl groups. Especially, it seems that the deterioration is remarkably accelerated by the chain breaking caused by the formation of aldehydic and acidic carbonyl groups and by the crosslinking caused by the formation of esteric carbonyl group.(4) The values of crystallinity and syndiotactic diad, calculated from the ratio of absorbances (D1141/D1420, D916/D849), tend to increase.(5) The formation of ozonides is recognized and the ozone-initiated reaction is expected to take place from the consideration of the reaction process or the mechanism of deterioration.(6) The coloration is attributed to the chromophores (>C=O) and the bathochromic effect of auxochromes (-OH), and the degree of coloration is larger in nitrogen atmosphere than in oxygen.

A No-Cultivation Concept for Vegetable Gardening1

Abstract A uniform and convenient herbicide application technique was developed for home vegetable gardens. 4-(Methylsulfonyl)-2,6-dinitro-N,N-dipropylanaline (nitralin) was either sprayed on the soil surface, or applied to 1 m wide sheets of water soluble plastic. A light sprinkling of water released the nitralin from the water soluble plastic and permitted soil adsorption. Weed control was excellent when 3.4 kg/ha nitralin was applied to the soil with water soluble plastic. Germinating vegetable seeds were protected from nitralin injury with a mixture of activated carbon and vermiculite. The “no-cultivation concept” may have broad horticultural application, especially in home gardens where herbicides are difficult to use.

A replica technique for conventional and scanning electron microscopy

A replica technique, which makes use of a water soluble plastic, has been developed for the examination of surfaces in the conventional and scanning electron microscopes.