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1.
J Environ Manage ; 370: 122599, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39340884

RESUMO

Diethyl phthalate (DEP) is a typical environmentally organic pollutant, widely used in the production process of polyvinyl chloride (PVC) to improve the flexibility of plastic materials. Its interaction with living organisms can inflict considerable harm to reproductive system functions. This research aims to utilize tetrahydrofuran (THF) to selectively break the chemical bonds in PVC molecules to provide more adsorption sites. Then incorporates the plasticizing assembly process of PVC to instantly remove and recover DEP from wastewater, achieving waste utilization, and sustainable environmental development. The research found that PTFR with a concentration of around 75 mg/L shows the best DEP removal efficiency. Sequencing batch processing removes more DEP compared to direct processing under the same material usage conditions. Furthermore, the recovery rate of DEP can reach over 90%. The technology demonstrates notable enhancements in removal efficiency and adsorption duration when compared to conventional adsorption techniques. This research has established an instant and efficient method for DEP removal, providing a new idea and technology for plasticizer treatment in practical wastewater.

2.
Ultrason Sonochem ; 111: 107067, 2024 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39288593

RESUMO

Zein-based films exhibit high efficiency in ethylene adsorption. However, its brittleness limits the practical applications. To address this issue, this study synergizes the plasticizing effects of high-intensity ultrasound (HIU) and castor oil (CO) to reduce the brittleness of zein-based films. The plasticizing mechanism was demonstrated through the formation of new intermolecular hydrogen bonds and electrostatic interactions, as evidenced by fourier transform infrared spectroscopy (FTIR) and zeta potential measurements. The tensile strength of 6 % CO-zein film increased eightfold. Additionally, the freshness of mangoes stored with 6 % CO-zein film significantly improved, extending their shelf life from 5 days to 15 days. Therefore, this study investigated the synergistic plasticization of zein-based films through the addition of CO, based on HIU. It also provides a theoretical basis for fruit packaging.

3.
Int J Biol Macromol ; 279(Pt 2): 134866, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39233159

RESUMO

In this study, the PVA/starch blend films were prepared by dry melting method. The microstructure showed that the starch existed in the continuous PVA matrix in granular structure. When the amount of starch was 30 wt%, the tensile strength increased from 12.8 to 14.7 MPa, and the elastic modulus increased from 15.4 to 20.5 MPa, and the water absorption increased by about 2 %. The addition of starch increased the Tmax by 8.1-29.64 °C compared to pure PVA. Considering the mechanical, hydrophilic and optical properties of the blend films, PVA/starch at 7:3 was the most promising packaging material. Notably, the blend films exhibit great reusability and renewability. Overall, these findings highlight the potential of PVA/starch blend films as environmentally friendly materials with enhanced properties.


Assuntos
Álcool de Polivinil , Amido , Resistência à Tração , Amido/química , Álcool de Polivinil/química , Química Verde/métodos , Água/química , Temperatura , Interações Hidrofóbicas e Hidrofílicas , Módulo de Elasticidade , Plásticos/química
4.
Toxics ; 12(7)2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39058155

RESUMO

There is limited evidence about the gender- and obesity-specific effects of personal care product and plasticizing chemicals (PCPPCs) on short sleep duration in adults. We evaluated the gender- and obesity-specific association of co-exposure to PCPPCs and short sleep duration among adults aged 20-60 years using the National Health and Nutrition Examination Survey (NHANES) 2011-2016, a secondary data source from the United States. Seventeen PCPPCs, including five phenols, two parabens, and ten phthalates, were detected, and sleep duration was assessed among 3012 adults. Logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were employed. We found that bisphenol A (BPA), mono (caboxy-isooctyl) phthalate (MCOP), and mono (3-carboxypropyl) phthalate (MCPP) were consistently positively associated with short sleep duration in both females and males regardless of obesity status, except for BPA with general obesity. In particular, mono benzyl phthalate (MBzP) revealed a positive association in females, mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) revealed a positive association in males, and MiBP revealed a positive association in abdominal obesity. Similar associations were observed in the mixture. Our study highlights that PCPPCs are independently associated with an increasing risk of short sleep duration in adults both individually and as a mixture; however, gender- and obesity-specific differences may have little effect on certain individual PCPPCs on short sleep duration.

5.
Materials (Basel) ; 17(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38894045

RESUMO

The research presented here is an attempt to develop an innovative and environmentally friendly material based on bacterial nanocellulose (BNC), which will be able to replace both animal skins and synthetic polymer products. Bacterial nanocellulose becomes stiff and brittle when dried, so attempts have been made to plasticise this material so that BNC can be used in industry. The research presented here focuses on the ecological modification of bacterial nanocellulose with vegetable oils such as rapeseed oil, linseed oil, and grape seed oil. The effect of compatibilisers of a natural origin on the plasticisation process of BNC, such as chlorophyll, curcumin, and L-glutamine, was also evaluated. BNC samples were modified with rapeseed, linseed, and grapeseed oils, as well as mixtures of each of these oils with the previously mentioned additives. The modification was carried out by passing the oil, or oil mixture, through the BNC using vacuum filtration, where the BNC acted as a filter. The following tests were performed to determine the effect of the modification on the BNC: FTIR spectroscopic analysis, contact angle measurements, and static mechanical analysis. As a result of the modification, the BNC was plasticised. Rapeseed oil proved to be the best for this purpose, with the help of which a material with good strength and elasticity was obtained.

6.
Pharmaceutics ; 16(3)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38543195

RESUMO

Melt viscosity is an essential property in pharmaceutical processes such as mixing, extrusion, fused deposition modeling, and melt coating. Measuring and modeling of the melt viscosity for drug/polymer mixtures is essential for optimization of the manufacturing process. In this work, the melt viscosity of nine formulations containing the drug substances acetaminophen, itraconazole, and griseofulvin, as well as the pharmaceutical polymers Eudragit EPO, Soluplus, and Plasdone S-630, were analyzed with a rotational and oscillatory rheometer. The shear rate, temperature, and drug fraction were varied systematically to investigate their influence on viscosity. The results for the pure polymers showed typical shear-thinning behavior and are fundamental for modeling with the Carreau and Arrhenius approaches. The investigations of the viscosity of the drug/polymer mixtures resulted in a plasticizing or a filler effect, depending on the type of drug and the phase behavior. A drug shift factor was proposed to model the change in viscosity as a function of the drug fraction. On this basis, a universal model to describe the melt viscosity of drug/polymer mixtures was developed, considering shear rate, temperature, and drug fraction.

7.
Int J Pharm ; 651: 123807, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38220121

RESUMO

It is generally accepted that water as a plasticizer can decrease the glass transition temperatures (Tgs) of amorphous drugs and drug excipient systems. However, previous studies suggest that water, as an anti-plasticizer, can increase the Tgs of co-amorphous systems of prilocaine (PRL) and lidocaine (LID). In order to investigate the intermolecular interactions between water and co-amorphous PRL-LID systems, Fourier transform infrared spectroscopy (FTIR) and principal component analysis (PCA) were conducted. Water was found to bind with the carbonyl groups of PRL and LID molecularly evenly in the hydrated co-amorphous PRL-LID systems. Quantum chemical simulations visually confirmed the interactions between water and co-amorphous PRL-LID systems. Furthermore, the physical stability of hydrated co-amorphous PRL-LID systems was improved due to the anti-plasticizing effect of water, compared with the anhydrous samples. The preference of water to interact with the carbonyl groups of PRL and LID as binding sites could be associated with the anti-plasticizing effect of water on the co-amorphous PRL-LID systems.


Assuntos
Lidocaína , Prilocaína , Prilocaína/química , Temperatura de Transição , Temperatura , Água , Espectroscopia de Infravermelho com Transformada de Fourier , Estabilidade de Medicamentos , Varredura Diferencial de Calorimetria , Solubilidade
8.
Polymers (Basel) ; 16(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38201812

RESUMO

A problem of modeling plastic injection forming (molding) is presented, including both the plasticizing system of the injection-forming machine and the mold. When modeling the plastic flow in the mold, the input quantities are essentially unknown, e.g., the plastic melt temperature. Thus, a comprehensive (global) model of the injection-forming process is needed for the flow in the plasticizing system and in the mold. The process output quantities from the plasticizing system will be the input quantities for the mold. When modeling the plastic flow in the injection-forming machine, a comprehensive approach should be applied to consider the solid material conveying, material plasticizing, and the material melt flow. The model of material plasticizing is a basis for building such global models. In this research, the effect of the flow (including plasticizing) in the injection-forming machine on the flow in the mold is studied by simulation (using Moldex3D 2023R3OR 64-bit software) and experimentation. These studies are carried out for the injection forming of selected material using a specialized spiral mold. Simulations performed with the use of Moldex3D software for the plasticizing system significantly improved the accuracy of the simulation of the flow in the mold. However, the best results were obtained using experimental data (plastic melt temperature) as input quantities for mold filling simulations. The novel concepts of injection-forming process modeling based on our previous experimentations are also discussed.

9.
Eur J Pharm Biopharm ; 186: 1-6, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36878408

RESUMO

It is generally recognized that water, acting as a plasticizer, increases molecular mobility, leading to a decrease of the glass transition temperature (Tg) in amorphous systems. However, an anti-plasticizing effect of water was recently observed on prilocaine (PRL). This effect might be used in co-amorphous systems to moderate the plasticizing effect of water. Nicotinamide (NIC) can form co-amorphous systems with PRL. In order to investigate the effect of water on these co-amorphous systems, the Tgs and molecular mobility of hydrated co-amorphous NIC-PRL systems were compared with those of the respective anhydrous systems. Molecular mobility was estimated by considering the enthalpic recovery at the Tg using the Kohlrausch-Williams-Watts (KWW) equation. At molar ratios of NIC above 0.2, a plasticizing effect of water on co-amorphous NIC-PRL systems was observed with increasing the NIC concentration. In contrast, at molar ratios of NIC of 0.2 and below, water had an anti-plasticizing effect on the co-amorphous NIC-PRL systems, with increased Tgs and reduced mobility upon hydration.


Assuntos
Prilocaína , Água , Varredura Diferencial de Calorimetria , Temperatura de Transição , Fenômenos Químicos
10.
Front Nutr ; 10: 1335812, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38299182

RESUMO

In this study, thermoplastic starch (TPS) was prepared by melt extrusion process, in which glycerol and/or D-mannitol were used as plasticizers, and the effect of different glycerol/D-mannitol ratios (4:0, 3:1, 2:2, 1:3, and 0:4) on the physicochemical properties of the extruded starch samples was investigated. The short-range molecular order, crystallization, gelatinization, thermal stability, and thermal properties of the TPS samples were analyzed through attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), rapid visco analysis (RVA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results showed that the crystallinity and short-range molecular order of the TPS samples increased with increasing glycerol content. Conversely, the water absorption index (WAI) and water solubility index (WSI) of the TPS samples decreased with increasing glycerol content. In addition, the TPS samples with higher glycerol content exhibited higher gel and thermal stabilities. This study provides a theoretical basis for starch extrusion and plasticization in the preparation of TPS-based materials with specific properties.

11.
Materials (Basel) ; 15(13)2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35806505

RESUMO

The influence of a complex application of both plasticizing and air-entraining effects on concrete with polycarboxylate ether superplasticizer (PCE), air-entraining admixture (AIR), or an anti-foaming agent (AF) is analyzed in this paper with considerations for on the air content, workability, flexural and compressive strength, and freezing-thawing resistance of hardened cement mixtures. The effect of the complex behavior of PCE, AIR, and AF on the porosity of hardened cement mortar (HCM) and freezing-thawing resistance was investigated; freezing-thawing resistance prediction methodology for plasticized mortar was also evaluated. The results presented in the article demonstrate the beneficial influence of entrained air content on consistency and stability of cement mortar, closed porosity, and durability of concrete. Freezing-thawing factor KF depending on porosity parameters can be used for freezing-thawing resistance prediction. With both plasticizing (decrease in the water-cement ratio) and air-entraining effects (increase in the amount of entrained air content), the frost resistance of concrete increases, scaling decreases exponentially, and it is possible to obtain great frost resistance for cement-based material.

12.
Polymers (Basel) ; 14(14)2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35890667

RESUMO

Glass fiber-reinforced phenolic resins are well suited to substitute aluminum die-cast materials. They meet the high thermomechanical and chemical demands that are typically found in combustion engine and electric drive train applications. An injection molding process development for further improving their mechanical properties by increasing the glass fiber length in the molded part was conducted. A novel screw mixing element was developed to improve the homogenization of the long fibers in the phenolic resin. The process operation with the mixing element is a balance between the desired mixing action, an undesired preliminary curing of the phenolic resin, and the reduction of the fiber length. The highest mixing energy input leads to a reduction of the initial fiber length L0 = 5000 µm to a weighted average fiber length of Lp = 571 µm in the molded part. This is an improvement over Lp = 285 µm for a short fiber-reinforced resin under comparable processing conditions. The mechanical characterization shows that for the long fiber-reinforced materials, the benefit of the increased homogeneity outweighs the disadvantages of the reduced fiber length. This is evident from the increase in tensile strength from σm = 21 MPa to σm = 57 MPa between the lowest and the highest mixing energy input parameter settings.

13.
Mol Pharm ; 19(9): 3199-3205, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-35876141

RESUMO

Water is generally regarded as a universal plasticizer of amorphous drugs or amorphous drug-containing systems. A decrease in glass-transition temperature (Tg) is considered the general result of this plasticizing effect. A recent study exhibits that water can increase the Tg of amorphous prilocaine (PRL) and thus shows an anti-plasticizing effect. The structurally similar drug lidocaine (LID) might show similar interactions with water, and thus an anti-plasticizing effect of water is hypothesized to also occur in amorphous LID. However, the influence of water on the Tg of LID cannot be determined directly due to the very low stability of LID in the amorphous form. It is possible to predict the Tg of LID from a co-amorphous system of PRL-LID using the Gordon-Taylor equation. Interactions were observed between PRL and LID based on the deviations between the experimental Tgs and the Tgs calculated by the conventional use of the Gordon-Taylor equation. A modified use of the Gordon-Taylor equation was applied using the optimal co-amorphous system as a separate component and the excess drug as the other component. The predicted Tg of fully hydrated LID could thus be determined and was found to be increased by 0.9 ± 0.7 K compared with the Tg of water-free amorphous LID. It could be shown that water exhibited a small anti-plasticizing effect on LID.


Assuntos
Vidro , Lidocaína , Varredura Diferencial de Calorimetria , Temperatura , Temperatura de Transição
14.
J Fungi (Basel) ; 8(3)2022 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-35330319

RESUMO

Sustainable substitutes for leather can be made from mushroom mycelium, which is an environmentally friendly alternative to animal and synthetic leather. Mycelium-based leather is derived from Polyporales, in which lignocellulosic material is used as the substrate. The plasticizing and crosslinking of mycelial mats with various reagents might affect the leather properties and mycelial architecture. This study investigated the physicochemical and mechanical properties of mycelium-based leather (MBL) samples, including the hygroscopic nature, thermal stability, cell wall chemistry, density, micromorphology, tensile strength, elongation rate, and Young's modulus. Micromorphological observations confirmed the mycelial networks and their binding performance, verifying their efficacy as a substitute leather. The most significant effects were observed after treatment with 20% polyethylene glycol, which resulted in an increase in Young's modulus and tensile strength. Furthermore, the samples generally exhibited a high density (1.35, 1.46 g/cm3) and tensile strength (7.21 ± 0.93, 8.49 ± 0.90 MPa), resembling leather. The tear strength reached as low as 0.5-0.8 N/mm. However, the tensile and tear strength may be affected by leather processing and the tuning of mycelial growth. Nevertheless, high-density mycelia are shown to be suitable for the production of MBL, while mycofabrication and strain selection are sustainable for novel industrial applications of MBL.

15.
Appl Biochem Biotechnol ; 194(3): 1290-1302, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34677760

RESUMO

More and more industries demand environmental friendliness. Silkworm pupae oil (SPO), extracted from the desilked silkworm pupae, can serve as a promising substrate alternative to use in plasticization. This study aimed to prepare epoxidized silkworm pupae oil (ESPO) and investigate their effects on the thermal stability and plasticization of polyvinyl chloride (PVC) films. A chemo-enzymatic method of ESPO was developed in the presence of Lipase SMG1-F278N and H2O2 in natural deep eutectic solvents (DESs). Lipase SMG1-F278N could initiate the epoxidation reaction effectively at room temperature with a negligible loss of activities 10 batches. A maximum oxirane value of 6.94% was obtained. The formation of oxirane ring in ESPO was confirmed by FTIR and 13C NMR spectra. Moreover, ESPO showed a better thermal stability and lower freezing point than epoxidized soybean oil (ESO). It was demonstrated that ESPO had a good frost resistance. In addition, ESPO showed a significantly improved plasticizing effect on flexible polyvinyl chloride (PVC). Compared with ESO, ESPO could increase the tensile elongation at break effectively. A significantly lower migration rate of plasticizer was observed in PVC plasticized with ESPO.


Assuntos
Cloreto de Polivinila
16.
Polymers (Basel) ; 13(15)2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34372016

RESUMO

Ultrasonic molding (USM) is a good candidate for studying the plasticization of polymer mixtures or other composite materials due to either the little amount of material needed for processing, low waste or the needed low pressure and residence time of the mold. Thus, the novelty of this research is the capability of USM technology to process PLA/PCL blends and their corresponding neat materials, encompassing all the production stages, from raw material to the final specimen. The major findings of the work revealed that the thermal properties of the blends were not affected by the USM process, although the crystallinity degree experienced variations, decreasing for PLA and increasing for PCL, which was attributed to the crystallization rate of each polymer, the high process speed, the short cooling time and the small particle size. The employed ultrasonic energy increased the molecular weight with low variations through the specimen. However, the degradation results aligned with the expected trend of these material blends. Moreover, this study also showed the effect pellet shape and dimensions have over the process parameters, as well as the effect of the blend composition. It can be concluded that USM is a technology suitable to successfully process PLA/PCL blends with the correct determination of process parameter windows.

17.
Polymers (Basel) ; 13(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34372095

RESUMO

In this study, fiber breaking behavior, fiber orientation, length variation, and changes in melt flow ability of long glass fiber reinforced polypropylene (L-FRP) composites under different mold cavity geometry, melt fill path, and plasticization parameters were investigated. The matrix material used was polypropylene and the reinforcement fibers were 25 mm long. An ultra-long-fiber composite injection molding machine (with a three-stage plunger and injection mechanism design) was used with different mold cavity geometry and plasticization parameters. Different screw speeds were used to explore the changes in fiber length and to provide a reference for setting fiber length and parameter combinations. Flow-length specimen molds with different specimen thickness, melt fill path, and gate design were used to observe the effect of plasticizing properties on the flow ability of the L-FRP composite materials. The experimental results showed that the use of an injection molding machine with a mechanism that reduced the amount of fiber breakage was advantageous. It was also found that an increase in screw speed increased fiber breakage, and 25 mm long fibers were shortened by an average of 50% (to 10 mm). Long fibers were more resistant to melt filling than short fibers. In addition, the thickness of the specimen and the gate design were also found to affect the filling process. The rounded angle gate and thick wall product decreased the flow resistance and assisted the flow ability and fiber distribution of the L-FRP injection molding.

18.
Polymers (Basel) ; 13(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34451191

RESUMO

The optimal machine settings in polymer processing are usually the result of time-consuming and expensive trials. We present a workflow that allows the basic machine settings for the plasticizing process in injection molding to be determined with the help of a simulation-driven machine learning model. Given the material, screw geometry, shot weight, and desired plasticizing time, the model is able to predict the back pressure and screw rotational speed required to achieve good melt quality. We show how data sets can be pre-processed in order to obtain a generalized model that performs well. Various supervised machine learning algorithms were compared, and the best approach was evaluated in experiments on a real machine using the predicted basic machine settings and three different materials. The neural network model that we trained generalized well with an overall absolute mean error of 0.27% and a standard deviation of 0.37% on unseen data (the test set). The experiments showed that the mean absolute errors between the real and desired plasticizing times were sufficiently small, and all predicted operating points achieved good melt quality. Our approach can provide the operators of injection molding machines with predictions of suitable initial operating points and, thus, reduce costs in the planning phase. Further, this approach gives insights into the factors that influence melt quality and can, therefore, increase our understanding of complex plasticizing processes.

19.
Materials (Basel) ; 14(4)2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33578880

RESUMO

This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.

20.
Int J Biol Macromol ; 166: 1508-1512, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33181216

RESUMO

In this study, we developed a novel method to prepare chemical fibers by plasticizing cotton with 1-allyl-3-methylimidazolium chloride (AMIMCl) under high temperature and pressure. Cotton was homogeneously mixed with AMIMCl by kneading in a certain mass proportion. It would be a sheet after hot-pressing and this process could be repeated several times. The morphologies of chemical fibers showed that cotton was successfully plasticized by AMIMCl with the crystallinity of the chemical fibers increased by about 15%. Differential scanning calorimetry (DSC) showed that the glass transition temperature (Tg) occurred in chemical fibers and we could further verify cotton was plasticized by AMIMCl. This simple and green method will be helpful to modify and broaden the application field of cotton.


Assuntos
Compostos Alílicos/química , Fibra de Algodão , Imidazóis/química , Plastificantes/química , Indústria Têxtil/métodos , Temperatura de Transição , Vitrificação
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