Showing papers on "Polystyrene published in 2018"
TL;DR: This paper reviews studies on biodegradation of polystyrene to give an overview and direction for future studies.
Abstract: Polystyrene is a widely used plastic in many aspects of human life and in industries due to its useful characteristics of low cost, light weight, ease of manufacture, versatility, thermal efficiency, durability, and moisture resistance. However, polystyrene is very stable and extremely hard to degrade in the environment after disposal. Polystyrene can be used as a carbon source for microorganisms similar to many other hydrocarbons. The ability of microorganisms to use polystyrene as a carbon source has been recently established. However, the high molecular weight of polystyrene limits its use as a substrate for enzymatic reactions to take place. In this paper, we review studies on biodegradation of polystyrene to give an overview and direction for future studies.
232 citations
91 citations
TL;DR: In this article, a co-pyrolysis of waste biomass and plastics was investigated to find out whether the quality of pyrolytic products was improved by co-processing.
85 citations
08 Mar 2018
TL;DR: Li et al. as mentioned in this paper proposed a chitosan-coated magnetite with Covalently Grafted Polystyrene Based Carbon Nanocomposites for Hexavalent Chromium Adsorption.
Abstract: 46 | Eng. Sci., 2018, 1, 46–54 © Engin 1 Shanghai Key Lab of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai 200092, People’s Republic of China. E-mail: hongbogu2014@tongji.edu.cn 2 Integrated Composites Laboratory (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee, 37966, USA MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, Shaanxi Key Laboratory of Macromolecular Science and Technology, Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi’ an, Shaanxi, 710072, P. R. China. E-mail: gjw@nwpu.edu.cn Chitosan-coated-magnetite with Covalently Grafted Polystyrene Based Carbon Nanocomposites for Hexavalent Chromium Adsorption
85 citations
TL;DR: In this article, the microencapsulation ratio (ME.R) of polystyrene phase change material (PCM) with an emulsion polymerization technique was investigated.
84 citations
TL;DR: In this paper, three different carbonization temperatures (500, 700, and 900°C) were employed to synthesize different carbon nanostructures with different morphologies and carbonization temperature.
83 citations
TL;DR: In this paper, thermal degradation of medical plastic waste (the blends of medicinal plastic bottles and plastic infusion bag) that mainly composed of polystyrene (PS) and polypropylene (PP) is studied under both inert and oxidative atmospheres using in-situ FTIR, TG-MS and TG-GC/MS coupled analyses.
79 citations
TL;DR: Polystyrene (PS) grafted graphene nanoplatelets composite (PS-GNPs) was prepared by in-situ polymerization and applied as modifier to Styrene-butadiene-styrene for modified asphalt preparation as discussed by the authors.
69 citations
TL;DR: In this article, polystyrene (PS) is introduced to stabilize the perovskite component, grains and microstructures by forming PS-capped perovsite grains.
68 citations
TL;DR: In this article, the effect of SEPS-g-GMA copolymer with different ratios on the compatibility of blends was studied, and the epoxy groups in SEPS g-GMs had a chemical reaction with the carboxyl groups in the waste materials.
61 citations
15 Oct 2018
TL;DR: On the basis of frictional coefficient measurements and wear testing, the self-lubricating microcapsules-incorporated epoxy coatings on an aluminum plate indicate the excellent dispersibility of the micro Capsules in coatings and the favorable antifriction effects.
Abstract: The facile and efficient encapsulation of a lubricant oil in SiO2 wrapped polystyrene microcapsules is accomplished using a Pickering polymerization technique. Triton X-100-IPTS fumed SiO2 nanoparticles are used as emulsifiers for the formation of O/W Pickering emulsions and the stability factor of the Pickering emulsions was investigated. The as-obtained microcapsules are characterized by scanning electron microscope, thermogravimetric analysis, Fourier transform infrared spectra and dynamic laser scattering. These results suggest that the microcapsules display a spherical shape with a core content of ∼38.3%, an average diameter of 3.3 μm, a shell thickness is ∼900 nm and outstanding thermal stability for lubricant oil with a decomposition temperature of 250 °C. Moreover, the microcapsules are embedded into an epoxy resin for self-lubricating coatings. On the basis of frictional coefficient measurements and wear testing, the self-lubricating microcapsules-incorporated epoxy coatings on an aluminum plate indicate the excellent dispersibility of the microcapsules in coatings and the favorable antifriction effects.
TL;DR: The prodegraded high impact and general polystyrene (PS0) specimens were shown to be the most promising carbon sources for PHA biosynthesis; with 3-hydroxybutyrate and up to 12 mol % of 3-Hydroxyvalerate and 3- hydroxyhexanoate co-monomeric units generated.
Abstract: Excessive levels of plastic waste in our oceans and landfills indicate that there is an abundance of potential carbon sources with huge economic value being neglected. These waste plastics, through biological fermentation, could offer alternatives to traditional petrol-based plastics. Polyhydroxyalkanoates (PHAs) are a group of plastics produced by some strains of bacteria that could be part of a new generation of polyester materials that are biodegradable, biocompatible, and, most importantly, non-toxic if discarded. This study introduces the use of prodegraded high impact and general polystyrene (PS0). Polystyrene is commonly used in disposable cutlery, CD cases, trays, and packaging. Despite these applications, some forms of polystyrene PS remain financially and environmentally expensive to send to landfills. The prodegraded PS0 waste plastics used were broken down at varied high temperatures while exposed to ozone. These variables produced PS flakes (PS1–3) and a powder (PS4) with individual acid numbers. Consequently, after fermentation, different PHAs and amounts of biomass were produced. The bacterial strain, Cupriavidus necator H16, was selected for this study due to its well-documented genetic profile, stability, robustness, and ability to produce PHAs at relatively low temperatures. The accumulation of PHAs varied from 39% for prodegraded PS0 in nitrogen rich media to 48% (w/w) of dry biomass with the treated PS. The polymers extracted from biomass were analyzed using nuclear magnetic resonance (NMR) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) to assess their molecular structure and properties. In conclusion, the PS0–3 specimens were shown to be the most promising carbon sources for PHA biosynthesis; with 3-hydroxybutyrate and up to 12 mol % of 3-hydroxyvalerate and 3-hydroxyhexanoate co-monomeric units generated.
TL;DR: A magnetic sorbent was fabricated by polystyrene coated on the magnetic graphene oxide for the extraction and preconcentration of PAHs in water samples prior to their determination by gas chromatography with flame ionization detection.
Abstract: A magnetic sorbent was fabricated by coating the magnetized graphene oxide with polystyrene (PS) to obtain a sorbent of the type GO-Fe3O4@PS. The chemical composition and morphology of the sorbent were characterized. The sorbent was employed for the enrichment of polycyclic aromatic hydrocarbons (PAHs) from water samples. Various parameters affecting the enrichment were investigated. The PAHs were then quantified by gas chromatography with flame ionization detection. Linear responses were found in the range of 0.03–100 ng mL−1 for naphthalene and 2-methylnaphthalene, and of 0.01–100 ng mL−1 for fluorene and anthracene. The detection limits (at an S/N ratio of 3) range between 3 and 10 pg mL−1. The relative standard deviations (RSDs) for five replicates at three concentration levels (0.05, 5 and 50 ng mL−1) of analytes ranged from 4.9 to 7.4%. The method was applied to the analysis of spiked real water samples. Relative recoveries are between 95.8 and 99.5%, and RSD% are <8.4%.
TL;DR: In this paper, microencapsulated phase change materials (MPCM) were added to geopolymer concrete (GPC) for utilization as a thermal energy storage concrete for passive building applications.
TL;DR: In this article, a low dense polystyrene sponge with superhydrophobicity and compressibility was prepared successfully by a dual-templating method, including High Internal Phase Emulsions (HIPEs) processing and the introduction of organic template species.
TL;DR: In this paper, a polystyrene-based form-stable composite phase change materials (CPCMs) were fabricated by a solution and reflux method, where the n-octadecane (ODE) was used as thermal energy storage material, and expanded graphite was employed as thermal conductive filler to improve the thermal conductivity of the composites.
TL;DR: The physical and thermodynamic properties of nanodiscs made with two different SMA copolymers, including a widely used and commercially available statistical poly(styrene- co-maleic acid) copolymer (coSMA) and a reversible addition-fragmentation chain transfer synthesizedCopolymer with narrow molecular weight distribution and alternating styrene and maleic acid groups with a polystyrene tail, are determined.
TL;DR: Quality of oil from pyrolysis of polystyrene were assessed for the possible applicability in fuel production and significant factor of using microwave heating is the amount of energy converted (kWh) is lesser than conventional heating.
TL;DR: The phase behavior of salt-containing block copolymers, plotted on a segregation strength versus copolymer composition plot, is similar to that of conventional (uncharged) blockCopolymer melts, when the parameter χeff replaces χ in segregation strength.
Abstract: We present experimental results on the phase behavior of block copolymer/salt mixtures over a wide range of copolymer compositions, molecular weights, and salt concentrations. The experimental system comprises polystyrene- block-poly(ethylene oxide) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. It is well established that LiTFSI interacts favorably with poly(ethylene oxide) relative to polystyrene. The relationship between chain length and copolymer composition at fixed temperature is U-shaped, as seen in experiments on conventional block copolymers and as anticipated from the standard self-consistent field theory (SCFT) of block copolymer melts. The phase behavior can be explained in terms of an effective Flory-Huggins interaction parameter between the polystyrene monomers and poly(ethylene oxide) monomers complexed with the salt, χeff, which increases linearly with salt concentration. The phase behavior of salt-containing block copolymers, plotted on a segregation strength versus copolymer composition plot, is similar to that of conventional (uncharged) block copolymer melts, when the parameter χeff replaces χ in segregation strength.
TL;DR: In this article, the relative performance of flame-retardant additives in polymer during well-developed fire has been investigated in a cone calorimeter, and the nanocomposites had an overall better flame retardancy than the neat polystyrene in terms of lower peak heat release rate, lower average mass loss rate and enhanced char formation.
Abstract: Using nanofiller additives in the polymer matrix to form nanocomposites is a potential way of reducing the flame spread and enhancing flame retardancy of polymeric materials during fire. To understand the fire reaction properties and the relative performance of flame-retardant additives in polymer during well-developed fire, neat polystyrene, polystyrene–silica and polystyrene–nanoclay (MMT) have been tested in a cone calorimeter. The neat polystyrene and the polystyrene nanocomposites have been prepared via an in situ polymerization method. An external heat flux of 50 kW m−2 was applied in the test, and parameters such as heat release rate, peak heat release rate, time to ignition, smoke toxicity, CO and CO2 yield have been investigated. Both neat polystyrene and polystyrene nanocomposites have shown the trend of a thermally thick charring polymer in the heat release rate over time data. The nanocomposites had an overall better flame retardancy than the neat polystyrene in terms of lower peak heat release rate, lower average mass loss rate and enhanced char formation. The nanocomposites had also reduced smoke emission with lower CO and CO2 yield compared to the neat polystyrene. The overall flame retardancy was enhanced as the nanofiller loading was increased for both the nanosilica and MMT nanocomposites.
TL;DR: In this article, a UV-LEDs floating photocatalytic reactor was developed in order to remove caffeine and paracetamol from water using ZnO immobilized on low density macroscopic polystyrene pellets as floating photocATalyst.
TL;DR: In this article, the impact of a supersonic micro-projectile initiates crazing, yielding, and adiabatic heating leading to extensive plastic flow of a loadbearing viscoelastic melt prior to perforation and film rupture.
TL;DR: In this article, a combined experimental and kinetic Monte Carlo simulation study of the direct (i.e., statistical) living anionic copolymerization of a mixture of isoprene (I) and 4-methylstyrene (4MS) in nonpolar media was investigated on a fundamental level.
Abstract: Block copolymers of polyisoprene and polystyrene are key materials for polymer nanostructures as well as for several commercially established thermoplastic elastomers. In a combined experimental and kinetic Monte Carlo simulation study, the direct (i.e., statistical) living anionic copolymerization of a mixture of isoprene (I) and 4-methylstyrene (4MS) in nonpolar media was investigated on a fundamental level. In situ 1H NMR spectroscopy enabled to directly monitor gradient formation during the copolymerization and to determine the nature of the gradient. In addition, a precise comparison with the established copolymerization of isoprene and styrene (I/S) was possible. Statistical copolymerization in both systems leads to tapered block copolymers due to an extremely slow crossover from isoprene to the styrenic monomer. For the system I/4MS the determination of the reactivity ratios shows highly disparate values with rI = 25.4 and r4MS = 0.007, resulting in a steep gradient of the comonomer composition. Th...
TL;DR: The results show that compared with pure PSt, the P(SPMA- co-St) polymer nanospheres exhibited better antiwear property as an additive for water lubrication, and the friction coefficient and the wear volume first decreased and then increased with the increase of the SPMA content, indicating that the hydrophilic SPMA has a significant effect on lubrication properties owing to its hydration performance.
Abstract: Amphiphilic polymer nanospheres of poly(3-sulfopropyl methacrylate potassium salt-co-styrene) [P(SPMA-co-St)] were prepared by a simple soap-free emulsion polymerization method and used as efficient water lubrication additives to enhance the antiwear behaviors of the Ti6Al4V alloy. The monodisperse and flexible P(SPMA-co-St) bicomponent copolymer nanospheres were synthesized with a controllable manner by adjusting the mass fraction ratio of the monomers, with the hydrophobic polystyrene (PSt) as the hard skeletal carrier component and the hydrophilic PSPMA with a hydration layer structure as the soft lubrication layer in the course of friction. The influences of the monomer concentration, the copolymer nanosphere additive content, the load, and the frequency of the friction conditions on their tribological properties were studied in detail, and a probable antiwear mechanism of the soft/hard-coupled copolymer nanospheres under water lubrication was also proposed. The results show that compared with pure PS...
TL;DR: In this article, the authors presented the design and synthesis of a polymer support sustainable heterogeneous [PS-Zn(II)L] catalyst from modified chloromethylated polystyrene, which showed its efficient catalytic activity towards the formation of organic cyclic carbonate from epoxides via CO2 fixation at room temperature under 1 atm CO2 pressure in solvent free condition.
TL;DR: In this article, a selectively foamed morphology consisting of electrically conductive polycarbonate/polystyrene/carbon nanotube (PC/PS/CNT) ternary nanocomposites is constructed.
Abstract: Electrically conductive polycarbonate/polystyrene/carbon nanotube (PC/PS/CNT) ternary nanocomposites are prepared by blending with styrene-maleic anhydride copolymer as their compatibilizer. Interestingly, CNTs are selectively distributed in PC phase in the PC/PS/CNT nanocomposites. After foaming with supercritical carbon dioxide as the foaming agent, most cells preferentially localize in the readily foamed PS phase; whereas, few cells appear in the PC matrix. Therefore, a selectively foamed morphology consisting of electrically conductive PC/CNT continuous phase and the foamed PS dispersed phase is well constructed. Due to the selective localization of CNTs, the PC70/PS30/CNT nanocomposite foams with PC as the matrix exhibits a much lower conducting percolation threshold of 0.35 vol% than the PC30/PS70/CNT nanocomposite foams with foamed PS as the matrix (0.94 vol%). The high electrical properties of the PC70/PS30/CNT foams are attributed to the conducting network of CNTs within the continuous PC matrix and the volume-exclusion effect of the preferentially foamed PS dispersed phase. More interestingly, PC70/PS30/1%CNT nanocomposite foam also exhibits much higher mechanical properties than PC30/PS70/1%CNT nanocomposite foam and a significant increase of 245% in notched Izod impact strength is achieved in relative to its bulk counterpart due to the toughening effect of the foamed PS particles.
TL;DR: The obtained CsPbBr3@SiO2 exhibits high stability in polar solvents and can be used as a solution-processable luminescent ink.
TL;DR: In this article, a novel nano-composite adsorbent, NDA88-Cu, was successfully prepared by immobilization of HKUST-1 (a typical MOF) into hyper-crosslinked polystyrene networks.
TL;DR: In this article, a study of the SIS process of alumina using trimethylaluminum (TMA) and H2O in various polymer films using in situ dynamic spectroscopic ellipsometry (SE) enables time-resolved monitoring of the swelling of the polymer.
Abstract: Sequential infiltration synthesis (SIS) provides a successful route to grow inorganic materials into polymeric films by penetrating of gaseous precursors into the polymer, both in order to enhance the functional properties of the polymer creating an organic-inorganic hybrid material, and to fabricate inorganic nanostructures when infiltrating in patterned polymer films or in selfassembled block copolymers. A SIS process consists in a controlled sequence of metal organic precursor and co-reactant vapor exposure cycles of the polymer films in an atomic layer deposition (ALD) reactor. In this work, we present a study of the SIS process of alumina using trimethylaluminum (TMA) and H2O in various polymer films using in situ dynamic spectroscopic ellipsometry (SE). In situ dynamic SE enables time-resolved monitoring of the swelling of the polymer, which is relevant to the diffusion and retain of the metal precursor into the polymer itself. Different swelling behaviour of poly(methylmethacrylate) (PMMA) and polystyrene (PS) was observed when exposed to TMA vapor. PMMA films swell more significantly than PS films do, resulting in very different infiltrated Al2O3 thickness after polymer removal in O2 plasma. PMMA films reach different swollen states upon TMA exposure and reaction with H2O, depending on the TMA dose and on the purge duration after TMA exposure, which correspond to different amounts of metal precursor retained inside the polymer and converted to alumina. Diffusion coefficients of TMA in PMMA were extracted investigating the swelling of pristine PMMA films during TMA infiltration and shown to be dependent on polymer molecular weight. In situ dynamic SE monitoring allows to control the SIS process tuning it from an ALD-like process for long purge to a chemical vapour deposition - like process selectively confined inside the polymer films
TL;DR: In this article, hierarchical polystyrene@MoS2 core-shell structures were constructed by combining latex technology and self-assembly of oppositely charged MoS2 nanosheets onto the surface of poly styrene spheres.
Abstract: Two dimensional MoS2 acting as reinforcing fillers had attracted intense interests in recent years. However, the homogeneous dispersion of MoS2 nanosheets in polymer matrix and exact interface control were still difficult to achieve due to potent van der Waals forces and surface inactiveness. In this work, hierarchical polystyrene@MoS2 core-shell structures were constructed by combining latex technology and self-assembly of oppositely charged MoS2 nanosheets onto the surface of polystyrene spheres. The formed core-shell structures were characterized by X-ray diffraction, Fourier transform infrared, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and further employed as reinforcing fillers in a host polystyrene matrix by solvent blending method. It was clearly observed that the construction of polystyrene@MoS2 core-shell structures not only improved the dispersion of MoS2 in the matrix and the interfacial adhesion between MoS2 and polystyrene, but also obviously improved the thermal stability and fire safety of polystyrene. The method proposed here had proved to be an efficient and facile approach to fabricate polymer/MoS2 nanocomposites with good dispersion and markedly improved properties.