Showing papers on "Polystyrene published in 2017"
TL;DR: The metathesis of dioxaborolanes is reported, which is rapid and thermally robust, and used to prepare vitrimers from polymers as different as poly(methyl methacrylate), polystyrene, and high-density polyethylene that, although permanently cross-linked, can be processed multiple times by means of extrusion or injection molding.
Abstract: Windmills, cars, and dental restoration demand polymer materials and composites that are easy to process, assemble, and recycle while exhibiting outstanding mechanical, thermal, and chemical resistance. Vitrimers, which are polymer networks able to shuffle chemical bonds through exchange reactions, could address these demands if they were prepared from existing plastics and processed with fast production rates and current equipment. We report the metathesis of dioxaborolanes, which is rapid and thermally robust, and use it to prepare vitrimers from polymers as different as poly(methyl methacrylate), polystyrene, and high-density polyethylene that, although permanently cross-linked, can be processed multiple times by means of extrusion or injection molding. They show superior chemical resistance and dimensional stability and can be efficiently assembled. The strategy is applicable to polymers with backbones made of carbon-carbon single bonds.
766 citations
TL;DR: A high-performance thermal interface material based on exfoliated BNNSs and polystyrene (PS) microspheres was fabricated by latex blending and subsequent compression molding and exhibits a significant thermal conductivity enhancement.
Abstract: Rational distribution and orientation of boron nitride nanosheets (BNNSs) are very significant for a polymer/BNNS composite to obtain a high thermal conductivity at low filler content. In this paper, a high-performance thermal interface material based on exfoliated BNNSs and polystyrene (PS) microspheres was fabricated by latex blending and subsequent compression molding. In this case, BNNSs and PS microspheres first self-assembled to form the complex microspheres via strong electrostatic interactions between them. The as-prepared complex microspheres were further hot-pressed around the glass transition temperature, which brought the selective distribution of BNNSs at the interface of the deformed PS microspheres. As a consequence, a polymer composite with homogeneous dispersion and high in-plane orientation of BNNSs in PS matrix was obtained. Benefitted from this unique structure, the resultant composite exhibits a significant thermal conductivity enhancement of 8.0 W m–1 K–1 at a low filler content of 1...
177 citations
TL;DR: Graphitic carbon nitride/organic aluminum hypophosphites hybrids (g-C3N4/OAHPi) hybrids will provide a potential strategy to reduce the fire hazards of polystyrene (PS) through a melt blending method.
170 citations
TL;DR: In this paper, the effects of plastic type, catalyst and feedstock contact mode, as well as the type of carrier gas on product distribution were investigated using a tandem micro-pyrolyzer.
133 citations
TL;DR: A novel room-temperature-phosphorescence (RTP)-based oxygen detection platform by constructing core-shell nanoparticles with water-soluble polymethyloxazoline shells and oxygen-permeable polystyrene cores crosslinked with metal-free purely organic phosphors, which shows a very high sensitivity for DO.
Abstract: Highly sensitive optical detection of oxygen including dissolved oxygen (DO) is of great interest in various applications. We devised a novel room temperature phosphorescence (RTP) based oxygen detection platform by constructing core-shell nanoparticles with water-soluble polymethyloxazoline shells and oxygen-permeable polystyrene core crosslinked with metal-free purely organic phosphors. The resulting nanoparticles show a very high sensitivity (limit of detection (LOD) of 60nM DO) and can be readily used for oxygen quantification in aqueous environments as well as gaseous phase.
129 citations
TL;DR: The introduction of a host-guest interaction based on CDs enables the aqueous dispersion polymerization of water-immiscible monomers, and produces kinetically trapped nanostructures, which could be a powerful technique for nanomaterials synthesis.
Abstract: A one-step synthesis of nanotubes by RAFT dispersion polymerization of cyclodextrin/styrene (CD/St) complexes directly in water is presented. The resulted amphiphilic PEG-b-PS diblock copolymers self-assemble in situ into nanoparticles with various morphologies. Spheres, worms, lamellae, and nanotubes were controllably obtained. Because of the complexation, the swelling degree of polystyrene (PS) blocks by free St is limited, resulting in limited mobility of PS chains. Consequently, kinetically trapped lamellae and nanotubes were obtained instead of spherical vesicles. During the formation of nanotubes, small vesicles first formed at the ends of the tape-like lamellae, then grew and fused into nanotubes with a limited chain rearrangement. The introduction of a host–guest interaction based on CDs enables the aqueous dispersion polymerization of water-immiscible monomers, and produces kinetically trapped nanostructures, which could be a powerful technique for nanomaterials synthesis.
112 citations
TL;DR: In this paper, an in situ synthetic strategy for the construct of carbon doped TiO 2 (carbon-TiO 2 ) nanotubes using surface-sulfonated layer of polystyrene fibers/titania composites was proposed.
106 citations
TL;DR: In this paper, the superhydrophobic silica coatings were prepared by spin deposition technique from a mixture of hydrophobically modified silica particles and polystyrene.
85 citations
TL;DR: In this paper, a mixture of palmitic acid and capric acid eutectic mixture was encapsulated in polystyrene (PS) capsules as new latent heat thermal energy storage (LHTES) material for building applications.
73 citations
TL;DR: In this paper, two new parameters, SVR/Density and DPP/Ddensity, were introduced during the analysis of the moisture behavior and thermal performance of polystyrene thermal insulation tested with various properties and conditions.
70 citations
TL;DR: The results obtained show that froth flotation is a potential method for plastics separation, in particular for plastics with particle size greater than 2.0mm, and if the most hydrophilic plastic, that sinks, has a regular shape and higher density.
TL;DR: In this article, a pure dense membrane by polystyrene was made through the solution casting method at various concentrations and then the silica nanoparticles were added in different weight percentages to the pure membrane.
Abstract: In this paper, first, the pure dense membrane by polystyrene was made through the solution casting method at various concentrations and then the silica nanoparticles were added in different weight percentages to the pure membrane. The best permeability result for CO2 and N2 in pure polymer membrane was achieved in concentration of 10 wt% of high-impact polystyrene (HPS). Also, the impact of increasing the pressure of the tested gases was examined on permeability and selectivity of nanocomposite membrane. The results indicated, with the pressure increasing, the permeability coefficient of tested gases is reduced. The best selectivity of CO2 to N2 was obtained in nanocomposite membrane containing 4 wt% silica nanoparticles in HPS.
TL;DR: A series of crosslinked, comb-shaped polystyrene (PS) anion exchange membranes (AEMs) having C-16 alkyl side chain were synthesized by a Cu(I)-catalyzed "click chemistry" reaction, and subsequently azide-assisted self-crosslinking for alkaline fuel cell application as mentioned in this paper.
TL;DR: In this article, the authors investigated the properties of styrene-butadien-styrene (SBS) polymers with different structure (radial and linear) and different butadien:styrene ratio.
TL;DR: This study provides the simplest controllable H2 S source to study its biological functions, as there is no accumulation of toxic byproducts, and the donor materials from polystyrene films and hydrogels can be readily removed after releasing H2S.
Abstract: Hydrogen sulfide (H2 S) has been identified as an important cell-signaling mediator and has a number of biological functions, such as vascular smooth muscle relaxation, neurotransmission, and regulation of inflammation. A facile and versatile approach for H2 S production initiated by light irradiation and controlled by reaction with an amine or an amino acid was developed. The donor was synthesized in a one-pot reaction, and simple crystallization led to a yield of approximately 90 %. The synthetic strategy is scalable and versatile, and the H2 S donors can be expressed ina number of different molecular and macromolecular forms, including crystalline small-molecule compounds, water-soluble polymers, polystyrene films, and hydrogels. The H2 S donors based on polystyrene film and hydrogel were used as cell-culture scaffolds. The H2 S donor based on water-soluble polymer was applied in photocontrolled inhibition of P-selectin expression on human platelets and subsequent regulation of platelet aggregation. This study provides the simplest controllable H2 S source to study its biological functions. The developed materials are also new therapeutic platforms to deliver H2 S, as there is no accumulation of toxic byproducts, and the donor materials from polystyrene films and hydrogels can be readily removed after releasing H2 S.
TL;DR: In this paper, a foamed thermal insulation geopolymer composite based on polystyrene particles (PP) and metakaolin was developed, and the experimental results show that compressivestrength and flexural strength of the thermal insulating geopolymers composite decrease with increasing polystyre particle content.
TL;DR: It is described that the spontaneous emulsification of TPM droplets in water is caused by base-catalyzed hydrolysis, self-condensation, and the deprotonation of T PM.
Abstract: Colloidal particles of controlled size are promising building blocks for the self-assembly of functional materials. Here, we systematically study a method to synthesize monodisperse, micrometer-sized spheres from 3-(trimethoxysilyl)propyl methacrylate (TPM) in a benchtop experiment. Their ease of preparation, smoothness, and physical properties provide distinct advantages over other widely employed materials such as silica, polystyrene, and poly(methyl methacrylate). We describe that the spontaneous emulsification of TPM droplets in water is caused by base-catalyzed hydrolysis, self-condensation, and the deprotonation of TPM. By studying the time-dependent size evolution, we find that the droplet size increases without any detectable secondary nucleation. Resulting TPM droplets are polymerized to form solid particles. The particle diameter can be controlled in the range of 0.4 to 2.8 μm by adjusting the volume fraction of added monomer and the pH of the solution. Droplets can be grown to diameters of up t...
TL;DR: In this paper, co-pyrolysis of polystyrene (PS) and cellulose was performed in a Py-GC×GC/MS system at 450-600 °C with ratios 70:30, 50:50, and 30:70.
Abstract: Understanding of the interaction between cellulose and various plastics is crucial for designing waste-to-energy processes. In this work, co-pyrolysis of polystyrene (PS) and cellulose was performed in a Py-GC×GC/MS system at 450–600 °C with ratios 70:30, 50:50, and 30:70. Polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) were then added to the mixture with different ratios. It was found that co-pyrolysis of PS and cellulose promotes the formation of aromatic products with a large increase in the yield of ethylbenzene as compared to the calculated value from individual feedstock. This indicates interactions between cellulose and PS pyrolysis products. Observations from experiments including more than one type of plastics indicate that the interactions between different plastics are more pronounced than the interaction between plastics and cellulose.
TL;DR: In this article, fast scanning calorimetry (FSC) was employed to characterize the glass transition of polystyrene (PS) nanospheres, and the authors observed suppression of glass transition temperature in comparison to bulk PS, both in terms of limiting fictive temperature (Tf) and temperature range of vitrification.
Abstract: We employ fast scanning calorimetry (FSC) to characterize the glass transition of polystyrene (PS) nanospheres. We observe suppression of the glass transition temperature (Tg) in comparison to bulk PS, both in terms of limiting fictive temperature (Tf) and temperature range of vitrification. At the same time, the polymer molecular mobility is found to be independent of the nanospheres diameter and bulk-like. Importantly, apart from the fact that this result has been obtained on the same samples and experiments and at comparable time scales, in all cases, a perturbation of the entropy is induced. Hence, to understand these results, the conceptual difference between vitrification kinetics and molecular mobility is highlighted. The main consequence of the outcome of the present study is that arguments beyond those based on the modification of the molecular mobility must be accounted for to explain Tg suppression in polymer glasses subjected to nanoscale confinement.
TL;DR: A novel approach for the preparation of homogeneous polystyrene/silver nanocomposites utilizing Nitroxide Mediated Radical Polymerization (NMRP) is proposed, which exhibits effective antibacterial activity with respect to pathogenic bacteria.
TL;DR: Both the very poor bioavailability of polystyrene and its inert basic structure play important roles constraining biodegradability via biologically driven Fenton chemistry.
TL;DR: A series of two component interpenetrating polymer networks (IPN) of modified castor oil based polyurethane (PU) and polystyrene (PS) were prepared by the sequential method as mentioned in this paper.
TL;DR: In this paper, sulfonated polystyrene (SPS) spheres were used as templates and polyvinylpyrrolidone (PVP) was used as reducing agent and stabilizing agent.
Abstract: In this work, multifunctional sulfonated polystyrene/polyaniline/silver (SPS/PANI/Ag) nanocomposites are prepared through using sulfonated polystyrene (SPS) spheres as templates and utilizing polyvinylpyrrolidone (PVP) as reducing agent and stabilizing agent. Our method is an environmentally friendly method because no toxic reagents are added during the preparation process. Fourier transform infrared spectrum (FTIR), field emission scanning electron microscopy (FESEM), and energy disperse spectroscopy (EDX) results confirmed the formation of PS spheres, SPS spheres, SPS/PANI nanocomposites, and SPS/PANI/Ag nanocomposites. Powder X-ray diffraction (XRD) patterns indicate that the obtained Ag nanoparticles are crystalline. Solubilities measurements show that SPS/PANI/Ag nanocomposites have improved solubilities when compared to pure PANI in common organic solvents and deionized water. Antibacterial studies show that SPS/PANI/Ag nanocomposites can greatly inhibit the growth of Escherichia coli and Staphylococcus aureus. Anticorrosion studies show that the incorporation of SPS/PANI/Ag nanocomposites in waterborne alkyd resin can greatly promote the anticorrosive efficiency of waterborne alkyd resin.
TL;DR: The synthesis of a B-N analogue of polystyrene, poly(N-methyl-B-vinylazaborine) in high molecular weight (MW = 24.9 kDa) is presented.
TL;DR: In this paper, the technical feasibility of polystyrene-halloysite nanotube (PS-HNT) membranes, fabricated by an ultrasound-assisted solution casting method, was explored for water purification.
TL;DR: In this article, the authors reported on a Cu-sputtered film on polystyrene (PS) leading to the discoloration/degradation of methylene blue (MB) under low intensity solar simulated irradiation.
TL;DR: In this paper, a comprehensive review of high performance polystyrene/carbon nanotube composite is presented, where the significance of electromagnetic interference shielding phenomenon in poly styrene and carbon nanotubes composite is discussed.
Abstract: Polystyrene is an efficient thermoplastic having fine processability, chemical inertness, and mechanical performance. Technological advances have led to several industrial appliances of polystyrene-based materials ranging from insulation to electromagnetic interference shielding. In this state-of-the-art review, primarily structure and properties of carbon nanotube and polymer/carbon nanotube composite have been discussed. Carbon nanotube is considered as a brilliant filler for polymers. Therefore, a comprehensive discussion regarding high-performance polystyrene/carbon nanotube composite is presented. Main focus of review is the significance of electromagnetic interference shielding phenomenon in polystyrene/carbon nanotube composite. Owing to advantageous properties, these composite have potential to replace traditional shielding materials.
TL;DR: The combined technique can provide a simple and effective method for the selective separation of PVC from heavy plastics mixtures to facilitate easy industrial recycling.
TL;DR: A new template-free method based on dispersion polymerization was successfully developed to produce anisotropic hollow polystyrene (PS) microparticles in a single step and a plausible mechanism for formation of these unusually shaped PS microparticle was proposed.
Abstract: The design and preparation of hollow nonspherical microparticles are of great significance for their potential applications, but the development of a facile synthetic method using only one production step remains a great challenge. In the current work, a new template-free method based on dispersion polymerization was successfully developed to produce anisotropic hollow polystyrene (PS) microparticles in a single step. In the synthesis, ammonium persulfate (APS) played a critical role in the formation and growth of highly uniform and stable hollow PS microparticles. By varying the concentration of APS and that of the stabilizer used, polyvinylpyrrolidone, we were able to control the average size of the PS particles and their degree of concavity. Based on our results and observations, a plausible mechanism for formation of these unusually shaped PS microparticles was proposed.
TL;DR: In this paper, the effect of aromatic, π electron interactions on miscibility and on the structure and properties of polypropylene (PP)/lignin blends were used as a reference.
Abstract: Polymer/lignosulfonate blends were prepared from three polymers containing an aromatic moiety in their chain: polystyrene (PS), polycarbonate (PC), and a glycol modified poly(ethylene terephthalate) (PETG), in order to study the effect of aromatic, π electron interactions on miscibility and on the structure and properties of the blends. Polypropylene (PP)/lignin blends were used as a reference. The components were homogenized in an internal mixer and compression molded into plates of 1 mm thickness. Structure was characterized by scanning electron microscopy (SEM) and image analysis, while mechanical properties were characterized by tensile testing and acoustic emission measurements. Component interactions were estimated from solubility parameters, the composition dependence of glass transition temperature, and mechanical properties. The results indicated that π electron interactions result in better compatibility than the dispersion forces acting in PP blends. The average size of the dispersed lignin par...