Types Of Plastic Research Articles

The Effect of Differences in the Use of Flour and Plasticizers in Making Biodegradable Plastic on the Physical Characteristics of Beeswax

Plasticis is one of the objects that is necessary in daily activities. This is because plastics makes it easier for humans to package goods. Its elastic and easy-to-use properties make plastic widely used by humans. However, on the other hand, plastic has properties that are difficult to decompose (non-degradable) so it is one of the biggest generators of waste that pollutes the environment. Biodegradable plastic or commonly called bioplastic can be an alternative product to reduce plastic waste because it is easily decomposed and more environmentally friendly. This research examines the influence of the type of starch (avocado seed flour, manga seed flour, banana peel flour, cassava peel flour) and plasticizers (glycerol, sorbitol, and polyvinyl alcohol) with beeswax additives on the characteristics of the resulting bioplastic. The best tensile strength value was found in a sample of mango seed flour, PVA type plasticizer, 0.04 gram beeswax, namely 11.35 MPa. The best elongation value was found in samples of mango seed flour, glycerol type plasticizer, 0.04 gram beeswax, namely 67%. The best percentage degradation value is bioplastic using cassava peel starch. The best swelling index value was found in samples of avocado seed flour, sorbitol type plasticizer, 0.1 gram beeswax, namely 20.16%. In terms of water content values, all samples are in accordance with SNI, namely below 20%.

Fatigue Experiment and Failure Mechanism Analysis of Aircraft Titanium Alloy Wing-Body Connection Joint.

Taking the titanium alloy wing-body connection joint at the rear beam of a certain type of aircraft as the research object, this study analyzed the failure mechanism and verified the structural safety of the wing-body connection joint under actual flight loads. Firstly, this study verified the validity of the loading system and the measuring system in the test system through the pre-test, and the repeatability of the test was analyzed for error to ensure the accuracy of the experimental data. Then, the test piece was subjected to 400,000 random load tests of flight takeoffs and landings, 100,000 Class A load tests, and ground-air-ground load tests, and the test piece fractured under the ground-air-ground load tests. Lastly, the mechanism analysis and structural safety verification of the fatigue fracture of the joints were carried out by using a stereo microscope and scanning electron microscope. The results show that fretting fatigue is the main driving force for crack initiation, and the crack shows significant fatigue damage characteristics in the stable growth stage and follows Paris' law. Entering the final fracture region, the joint mainly experienced ductile fracture, with typical plastic deformation features such as dimples and tear ridges before fracture. The fatigue crack growth behavior of the joint was quantitatively analyzed using Paris' law, and the calculated crack growth period life was 207,374 loadings. This result proves that the crack initiation life accounts for 95.19% of the full life cycle, which is much higher than the design requirement of 400,000 landings and takeoffs, indicating that the structural design of this test piece is on the conservative side and meets the requirements of aircraft operational safety. This research is of great significance in improving the safety and reliability of aircraft structures.

Research on Plastic Recycling from a Global Perspective and PET Recycling Schemes in Hong Kong

This paper first introduces the global production volume and types of plastics, their impacts on the environment, and the current treatment status. Then it elaborates on the plastic recycling situations in Hong Kong, Taiwan, and Bernburg, Germany respectively. In Hong Kong, the plastic recycling rate is low, and landfill is the main treatment method, facing problems such as high transportation costs and low plastic density. Taiwan performs outstandingly in resource recycling with a high garbage recycling rate. Bernburg, Germany processes plastic waste through strict classification, incineration, and recycling factories. The article also details specific measures for the recycling object PET, including methods such as mechanical recycling, incineration, and landfill, as well as their advantages and disadvantages. Finally, it proposes feasible schemes for managing plastic waste in Hong Kong, such as garbage classification, mobilizing residents to recycle, building recycling stations, and internal digestion. It also analyzes the mechanical recycling technology for handling PET bottles in Hong Kong and the economic and environmental benefits of this project.

RESEARCH ON THE ELECTROMAGNETIC COMPATIBILITY OF MATERIALS FOR ORTHOPEDIC PROSTHETICS

Introduction. Acrylic plastics are widely used in orthopedic dentistry and orthodontics. They are the main material for the manufacture of various types of dental prostheses. To create an orthopedic product, a mixture of powder (polymer) and liquid (monomer) is obtained, from which a product of the required shape and size is formed and solidified. The resulting designs must meet the requirements for compatibility with living tissues, including the little-studied compatibility of the electromagnetic component. Main part. Dielectric materials when heated form their own electromagnetic radiation in the millimeter range, which is a general property of heated dielectrics. By this, electromagnetic flows (EMF) of different directions arise. These flows can have a positive or negative direction and in a certain way affect the adjacent biotissues and the human body as a whole. Therefore, the authors conducted studies of electromagnetic radiation (EMR) of 6 types of acrylic plastics, determined their levels and compared them with the level of EMR of biotissues of the human body. Based on the obtained results, conclusions were drawn regarding their electromagnetic compatibility (EMC). “Colorless basic plastic” and “Vertex Implacryl” have the highest level of EMC (up to 58%), “Ftorax” and “Sinma-M” plastics have a slightly lower level (48-53%) and the lowest EMC (35-36%) is recorded in “Vertex Basio” and “Ethakryl – 02”. Conclusions. Compared to the level of human electromagnetic radiation, acrylic plastics and, accordingly, dental prostheses from them form negative currents in relation to adjacent biotissues. The conducted studies allow to recommend the choice of more acceptable materials for the manufacture of dental permanent and removable prostheses, as well as to determine the correlation between the emission of electromagnetic characteristics and the appearance of complications in patients during the operation of these structures.

Observation and Control of Single-Component Adhesion Interphase of Polyamide 66 through Confocal Raman Microspectroscopy.

Manufacturing using adhesion technology has attracted much attention. Examples of adhesion include the lay-up of carbon fiber reinforced thermoplastic prepregs and the lamination of food packaging. In single-component adhesion systems, the analysis of the boundary region poses challenges because of the absence of chemical and physical discrimination at the adhesion interphase. Polyamide 66, one of the typical engineering plastics, is widely accepted as a structural material in automobiles and packaging films. Therefore, finer control of adhesion with polyamide 66 is crucial for advancing adhesion manufacturing. In this work, we focused and investigated the interphase of a single-component adhesion system with polyamide 66. For the analyses of single-component polyamide 66 laminates, an adhesion system with nondeuterated and deuterated polyamides was utilized, and their interphase structures were evaluated by confocal Raman microspectroscopy. The interphase region of the adhesion specimens was able to be characterized and evaluated, revealing an expansion to a thickness of several micrometers. The interphase thickness was increased with thermal annealing postlamination, whereas no thickness increase was observed in adhered specimens using the polyamide 66 substrates through thermal crystallization before lamination. The formation of the interphase region can be attributed to the crystal growing and lamella interlocking in the boundary region. Moreover, the larger interphase thickness was strongly associated with an increase in adhesion fracture toughness. These results suggested that the adhesion properties of crystalline substrates were decided by crystallization behavior and the thermal annealing process, even when using the same component adhesion systems.

Myosin XVA isoforms participate in the mechanotransduction-dependent remodeling of the actin cytoskeleton in auditory stereocilia.

Auditory hair cells form precise and sensitive staircase-like actin protrusions known as stereocilia. These specialized microvilli detect deflections induced by sound through the activation of mechano-electrical transduction (MET) channels located at their tips. At rest, a small MET channel current results in a constant calcium influx which regulates the morphology of the actin cytoskeleton in the shorter 'transducing' stereocilia. However, the molecular mechanisms involved in this novel type of activity-driven plasticity in the stereocilium cytoskeleton are currently unknown. Here, we tested the contribution of myosin XVA (MYO15A) isoforms, given their known roles in the regulation of stereocilia dimensions during hair bundle development and the maintenance of transducing stereocilia in mature hair cells. We used electron microscopy to evaluate morphological changes in the cytoskeleton of auditory hair cell stereocilia after the pharmacological blockage of resting MET currents in cochlear explants from mice that lacked one or all isoforms of MYO15A. Hair cells lacking functional MYO15A isoforms did not exhibit MET-dependent remodeling in their stereocilia cytoskeleton. In contrast, hair cells lacking only the long isoform of MYO15A exhibited increased MET-dependent stereocilia remodeling, including remodeling in stereocilia from the tallest 'non-transducing' row of the bundle. We conclude that MYO15A isoforms both enable and fine-tune the MET-dependent remodeling of the actin cytoskeleton in transducing stereocilia, while also contributing to the stability of the tallest row.

Fiber Reinforced Bioplastic from Food Waste (Potato peel)

The bioplastic is an evolution for plastic manufacturing units when conventional plastics use to cause various environmental issues. Biodegradability is an added advantage which can be obtained using bioplastic is that they are produced by renewal resources as a raw material for synthesis. Although, bioplastics may be classified into two types, that are biodegradable and non-biodegradable, depends on the type of plastic which are produced. Whereas, some of the bioplastics are non-biodegradable, the use of biomass in synthesizing the bioplastics will enhance in preserving non-renewable resources, which are inflammable, in producing conventional plastics. However, the mechanical strength of bioplastic still has scope for improvement in comparison with conventional plastics, which is having limited use and its application. Therefore, bioplastics required to be reinforced to improving its performance and properties to get the proper application of it. Synthetic reinforcement has been used to reinforce conventional plastic to achieve its desire properties to get the optimum application. Due to various issues, the trend has been diversified to use natural resources as reinforcements. There are different manufacturing units that have started to use reinforced bioplastic, and this article mainly tries to achieve the advantages of using reinforced bioplastic in various industries and its limitations. Thus, in this paper more emphasis is given to use the natural food waste which is available in ample quantity and possible to prepare the reinforced bioplastic of desired strength and environmentally friendly with biodegradability.

Structural and Functional Characterization of an Amidase Targeting a Polyurethane for Sustainable Recycling.

Global plastic production exceeded 400 million tons in 2022, urgently demanding improved waste management and recycling strategies for a circular plastic economy. While the enzymatic hydrolysis of polyethylene terephthalate (PET) has become feasible on industrial scales, efficient enzymes targeting other hydrolyzable plastic types, such as polyurethanes (PURs), are lacking. Recently, enzymes of the amidase signature (AS) family, capable of cleaving urethane bonds in a polyether-PUR analog and a linear polyester-PUR, have been identified. Herein, we present high-resolution crystal structures of the AS enzyme UMG-SP3 in three states: ligand-free, bound with a suicidal inhibitor mimicking the transition state, and bound with a monomeric PUR degradation product. Besides revealing the conserved core and catalytic triad akin to other AS family members, the UMG-SP3 structures show remarkable flexibility of loop regions. Particularly, Arg209 in loop 3 adopts two induced-fit conformations upon ligand binding. Through structure-guided kinetic studies and enzyme engineering, we mapped structural key elements that determine the enhanced hydrolysis of urethane and amide bonds in various small molecules, including a linear PUR fragment analog. Our findings contribute critical insights into urethanase activity, aiding PUR degradation campaigns and sustainable plastic recycling efforts in the future.

Structural and Functional Characterization of an Amidase Targeting a Polyurethane for Sustainable Recycling

AbstractGlobal plastic production exceeded 400 million tons in 2022, urgently demanding improved waste management and recycling strategies for a circular plastic economy. While the enzymatic hydrolysis of polyethylene terephthalate (PET) has become feasible on industrial scales, efficient enzymes targeting other hydrolyzable plastic types, such as polyurethanes (PURs), are lacking. Recently, enzymes of the amidase signature (AS) family, capable of cleaving urethane bonds in a polyether‐PUR analog and a linear polyester‐PUR, have been identified. Herein, we present high‐resolution crystal structures of the AS enzyme UMG‐SP3 in three states: ligand‐free, bound with a suicidal inhibitor mimicking the transition state, and bound with a monomeric PUR degradation product. Besides revealing the conserved core and catalytic triad akin to other AS family members, the UMG‐SP3 structures show remarkable flexibility of loop regions. Particularly, Arg209 in loop 3 adopts two induced‐fit conformations upon ligand binding. Through structure‐guided kinetic studies and enzyme engineering, we mapped structural key elements that determine the enhanced hydrolysis of urethane and amide bonds in various small molecules, including a linear PUR fragment analog. Our findings contribute critical insights into urethanase activity, aiding PUR degradation campaigns and sustainable plastic recycling efforts in the future.

Remote detection and identification of plastics with hyperspectral Raman imaging lidar

We report a hyperspectral Raman imaging lidar system that can remotely detect and identify typical plastic species. The system is based on a frequency-doubled, Q-switched Nd:YAG laser operating at 532 nm and an imaging spectrograph equipped with a gated intensified CCD spectrometer. Stand-off detection of plastics is achieved at 6 m away with a relatively wide field of view of 1 × 150 mm2, thus providing the groundwork for better solutions in monitoring marine plastic pollution.

UJI KARAKTERISTIK BAHAN BAKAR ALTERNATIF HASIL PENGOLAHAN LIMBAH SAMPAH PLASTIK DENGAN METODE PIROLISASI BERTINGKAT

This study aims to determine the characteristics and quantity of oil produced from first and second level pyrolysis. The method in this research is an experiment with a pyrolysis tool designed in two levels. The advantage of this pyrolysis tool compared to other pyrolysis tools is that it is expected to produce two fuels with different physical and chemical properties. The results of the study showed that for the first level of pyrolysis PP plastic, 855.7 grams of oil was produced with the following characteristics: density @15°C = 754 kg/m³, final boiling point = 264.9°C, distillation @200°C = 71.8% v/v. while in the second level pyrolysis for the PP plastic type, it produces 138.5 grams of oil with the following characteristics: density @15°C = 718.5 kg/m³, distillation at 10% evaporation volume = 74.4°C, distillation at 50% evaporation volume = 123°C, and distillation at 90% evaporation volume = 142.1°C, final boiling point = 189.7°C. The first level pyrolysis process on HDPE plastic initially only produced 418 grams of oil with the following characteristics: density @15°C = 751.5 kg/m³, final boiling point = 279.4°C, distillation @200°C = 70.9%v/v. The fuel produced from the first level pyrolysis process has characteristics comparable to kerosene, while the fuel produced in the second level pyrolysis process has characteristics equivalent to 88 octane fuel.

ESTIMATION OF PLASTIC PRODUCTION, CONSUMPTION, AND WASTE GENERATION IN NIGERIA: 2020 TO 2050

Global utilization of different types of plastics has been increasing over the years due to its many useful properties. However, disposal of plastic waste has been a challenge all over the world and Nigeria is not an exception. As the most populous country in Africa, Nigeria is among the highest consumer of plastic products. Plastic waste generation was considered using three different scenario that considered forecasted gross domestic production up to 2050. The results indicated that plastic production rate in Nigeria is linear as against plastic consumption rate which is exponential. The result estimates from 2020 to 2050 revealed that plastic consumption in Nigeria doubles every 9 years which was validated using the doubling time equation. However, substantial reduction was achieved if enhanced plastic waste management technologies is adopted. Further reduction is achievable through reuse, recycle and implementation of hierarchical waste management strategies.

Heterosynaptic plasticity: one name for several phenomena

Synaptic plasticity, which refers to long-term changes in the efficiency of synaptic transmission in the form of potentiation and depression, is thought to be a cellular mechanism of learning and memory. Long-term potentiation and depression can be induced under a variety of experimental conditions using different induction protocols. One such example is a protocol that follows Hebb’s rule, where induction of plasticity requires paired activation of a pre- and postsynaptic neuron that occur within a narrow temporal window relative to each other. Such plasticity is called homosynaptic plasticity because the same (homo-, Greek prefix meaning “same, identical”) synapses that participated in the induction of plasticity undergo long-term changes. However, as numerous experiments have shown, synapses that were inactive during the induction of plasticity also undergo long-term changes. This process has been termed heterosynaptic (hetero – “other, different”) plasticity in mammalian studies. Historically, however, the term heterosynaptic plasticity first appeared in studies of mollusks, where plastic changes in synaptic transmission were caused by a combination of stimulation of “weak” and “strong” synaptic inputs. As was later shown, the potentiating effect of stimulating the “strong” input in this case was associated with the release of neuromodulators, primarily serotonin. This type of plasticity was later demonstrated in mammals, where it was termed modulatory plasticity. The review considers different types of heterosynaptic plasticity, cellular and molecular mechanisms of its induction and maintenance, and explains the reasons for some terminological confusion related to this phenomenon in the literature.

Characteristics of heavy metal migration from virgin PET and recycled PET plastic bottles in beverage products

Polyethylene terephthalate (PET) is one of the most commonly used packaging materials for beverages. The increased use of PET has contributed to the rise in plastic waste. Recycled PET (R-PET) is a solution to address this environmental issue. This study aims to determine the migration level of Pb, Cd, Hg, and Sb in PET bottles, evaluate the effect of plastic types (virgin PET and R-PET) and testing conditions (according to BPOM following national regulation and EU following international regulation) on the migration from heavy metals into food. Sixty test samples of virgin PET and R-PET bottles, obtained from four packaging industries in Indonesia, were analyzed for Cd, Hg, Pb, and Sb concentrations using ICP-MS. The results showed that the highest concentrations of heavy metal migration for Cd and Pb were in a virgin PET sample according to BPOM, respectively, at 28 ± 2 ng/L and 636 ± 22 ng/L. Meanwhile, the highest concentrations of Hg and Sb were in a R-PET sample according to EU, respectively, at 469 ± 91 ng/L and 5042 ± 617 ng/L. There was a significant difference in heavy metal levels between the two types of plastic (virgin PET and R-PET) and two testing conditions (BPOM and EU). However, all the obtained concentrations were below the permitted limits of national and EU regulations.

Progress in the Study of Occurrence, Distribution, Material Flows, and Environmental Release of Substances of Very High Concern （SVHCs） in Plastics

Plastic additives provide plastics with excellent functions such as plasticizing, flame retardant, and antioxidant properties and are widely used in various plastics. Of these, 189 plastic additives have been included in the European Union's Candidate List of substances of very high concern （SVHCs） due to their potential environmental and health risks. These SVHCs are mainly used in PVC, PUR, and PE plastics and in the packaging, automotive, construction, electronic and electrical equipment, and textile sectors. Plasticizers and flame retardants are the most widely used and therefore the focus of SVHC risk assessment and risk management. Existing studies have carried out material flow analysis （MFA） for SVHCs in plastics, revealing the environmental and health risks of typical flame retardants and plasticizers throughout the product life cycle, such as polybrominated diphenyl ethers （PBDEs）, hexabromocyclododecane （HBCD）, and phthalic acid esters （PAEs）. A large amount of SVHCs enter waste streams at the end of the product life cycle, highlighting the importance of strengthening waste management for SVHCs risk management. In addition to the release of SVHCs from plastic products into the environment, plastic leakage is another important source of environmental release of SVHCs. Plastic debris that have been in the environment for a long time continue to release SVHCs and pose a long-term threat to the ecosystem and human health. In the future potentially hazardous chemicals must be crucially identified in different types of plastics and to assess their environmental release during their life cycle, in particular by establishing a database on hazardous chemicals in plastics and measuring emission factors, optimizing dynamic material flow analysis （d-MFA）, as well as studying the release mechanisms of hazardous chemicals from plastic leakage.

Long-Term Potentiation: The Accidental Discovery.

Long-term potentiation (LTP), is a type of synaptic plasticity now considered essential for learning and memory. Here I tell the story of how I accidentally discovered in 1966 in the laboratory of Per Andersen in Oslo, Norway, because I was not looking for it. It just emerged. I recount how I came to work with Per and why my result was not immediately followed up. Then, in 1968 Tim Bliss joined the lab and, on his urging, from 1968 to 1969 we did the experiments that resulted in Bliss and Lømo, 1973. I explain why I think the experiments later failed in Oslo, and for a few years also in Tim's lab in London, before it became a readily observable phenomenon. I also describe how Tony Gardner-Medwin and I in 1971 failed to reproduce the results that Tim and I had obtained 2 years earlier in the same lab and the same type of anesthetized rabbit preparation. I tell how this failure caused me to leave the LTP field and, instead, continue exploring mechanisms of nerve-muscle interactions, which I had studied with much success during my postdoc period in London from 1969 to 1971. I reflect on Donald Hebb's influence on LTP studies and on my experience when after many years of neglect, I became interested in LTP and the hippocampus anew and started to write about it, though without doing lab experiments. Finally, I report briefly on the experiments I am doing now in retirement, studying how the nervous system regulates body temperature through varying amounts of muscle tone.

Marine fungi degrade plastic and can be conditioned to do it faster

ABSTRACT Plastics are a prevalent and persistent pollutant in the environment. As plastic production increases, finding ways to degrade these recalcitrant polymers is paramount. Many terrestrial fungi, across the kingdom, degrade various types of plastic. Plastics are the fastest-growing habitat in the oceans, and we hypothesized that fungi isolated from the ocean would demonstrate high success rates in degrading polyurethane (PU). To test this, visual degradation assays were performed by inoculating 1% PU medium with 68 different fungal strains cultured from marine habitats. The area of clearance of the fungus was measured periodically, to determine a relative degradation rate. Of the 68 fungal strains, 42 demonstrated the ability to degrade PU. We conditioned the nine fastest PU degraders through serial inoculations into liquid media with increasing concentrations of PU, starting at 1% and going up to 12%. The growth rates of the original and conditioned fungi were then compared in new inoculation trials, and results show that three of the nine conditioned fungi demonstrate higher PU degradation rates than their unconditioned counterparts. Marine fungi, coupled with conditioning, show promise for developing novel mycoremediation technologies.

Microplastic particles in human blood and their association with coagulation markers

Recent studies have indicated potential health risks associated with microplastics (MPs) exposure, including alterations in blood coagulation homeostasis. This cross-sectional study aimed to quantitatively examine MPs in human blood and assess their association with coagulation markers. We recruited 36 healthy adults, collected whole blood samples, and analyzed MPs using Fourier-transform infrared (µ-FTIR) spectroscopy. Lifestyle factors related to MP exposure were assessed, such as the use of plastic food containers. Coagulation and inflammatory markers in blood samples were analyzed, including C-reactive protein, prothrombin time, activated partial prothrombin time (aPTT), antithrombin III, platelet count, erythrocyte sedimentation rate, and fibrinogen. MPs were detected in 88.9% of the participants, with a mean concentration of 4.2 MPs/mL. The predominant types of plastics identified were polystyrene and polypropylene. MPs were significantly higher in participants with a greater use of plastic food containers. A high MP load in the blood (≥ 3 MPs/mL) was significantly correlated with increased aPTT, C-reactive protein, and fibrinogen. We identified MPs in human blood, their association with specific lifestyle factors, and significant alterations in coagulation markers. This underscores the need for strategies to reduce human exposure to MPs, particularly in relation to blood coagulation and potential cardiovascular risks.

Physiochemical profiling of bioplasticizer derived from Ficus benghalensis leaves for eco-friendly applications

Physiochemical profiling of bioplasticizer derived from Ficus benghalensis leaves for eco-friendly applications

Polyester fibres slowly degrade in marine sediments

Microplastics are everywhere, including marine sediment. In this study, we evaluated the degradation of polyester, rayon, and cotton sewing threads over nine months when buried in marine sediment in Waitematā Harbour, Auckland, New Zealand. Polyester tensile strength was tested pre- and post-burial to track changes over time. Fourier-transform infrared spectroscopy (FTIR) analysis enabled the examination of the change to the chemical structural integrity of the polyester molecules over time. After one month, rayon and cotton degraded and were invisible to the eye, while visible signs of polyester degradation were apparent after 6 months of burial. This was confirmed by both tensile strength testing and FTIR chemical analysis. While microplastic pollution remains a serious problem, these findings show that at least one type of common plastic does degrade when buried in marine sediments. This likely has implications for seafloor ecosystem functionality and provides hope for plastic circular economy infrastructure.