Modification Of Polystyrene Research Articles

Post-Polymerization Modification of Polystyrene through Mn-Catalyzed Phosphorylation of Aromatic C(sp2)–H Bonds

Post-Polymerization Modification of Polystyrene through Mn-Catalyzed Phosphorylation of Aromatic C(sp²)–H Bonds

Enhancing Internal and External Stability of Perovskite Solar Cells Through Polystyrene Modification of the Perovskite and Rapid Open‐Air Deposition of ZnO/AlOx Nanolaminate Encapsulation

In this study, the internal and external stabilities of a p–i–n methylammonium lead iodide perovskite solar cell (PSC) are improved. Polystyrene (PS) is introduced into the perovskite layer to form a cross‐linked polymer–perovskite network, which enhances the nucleation and growth of the perovskite grains. Moreover, for the first time, 60 nm thick ZnO/AlOx nanolaminate (NL) thin‐film encapsulation (TFE) is deposited directly on the PSC using an atmospheric‐pressure (AP) spatial atomic layer deposition system operated in AP spatial chemical vapor deposition (AP–SCVD) mode. The rapid nature of AP–SCVD enables encapsulation of the PSCs in open air at 130 °C without damaging the perovskite. The PS additive improves the performance and internal stability of the PSCs by reducing ion migration. Both the PS additive and the ZnO/AlOx NL TFEs improve the external stability under standard test conditions (dark, 65 °C, 85% relative humidity [RH]) by preventing water ingress. The number and thickness of the ZnO/AlOx NL layers are optimized, resulting in a water–vapor transmission rate as low as 5.1 × 10−5 g m−2 day−1 at 65 °C and 85% RH. A 14‐fold increase in PSC lifetime is demonstrated; notably, this is achieved using PS, a commodity‐scale polymer, and AP–SCVD, a scalable, open‐air encapsulation method.

Influence of Non-Melting Waste Plastics on Volumetric Properties and Performance of Asphalt Mixtures

The main objective of the study is to evaluate the impact of using polystyrene (PS) and polyethylene terephthalate (PET) plastics as an additive in asphalt mixtures. For this purpose, volumetric modification, moisture susceptibility along with performance variation at high, intermediate, and low temperature conditions were evaluated. Initially plastics were subjected to calorimeter analysis for assessing their melting characterization. Both PS and PET are included as dry mix additives individually at dosage levels of 3%, 6%, and 9% by weight of asphalt binder. Further, the changes in thermal properties of plastics occurring during mixture preparation were correlated to better understand the volumetric modification. PS, owing to its glass transition and partial amorphous nature, exhibited minimum deviation (<1%) from design air voids (4 ± 0.5%). PET was observed to increase the volumes of voids in mineral aggregate (VMA) and air void, owing to its crystalline nature. As regards performance, PS and PET modification enhanced the moisture resistance by 1.05 to 1.11 times the control mixture. The rutting tolerance index ( RTindex) value increased for all plastic modified mixtures from the indirect tensile asphalt rutting test (IDEAL RT) performed at 58°C. However, the intermediate temperature cracking tolerance index ( CTindex) at 19°C conveyed the high embrittled nature from plastic modification making the mixtures more susceptible to cracking. From the Gf versus l75 /m75 interaction diagram, it was conveyed that although addition of plastics improves the fracture toughness of asphalt mixtures, the ductile nature of mixtures is compromised. Also, PS and PET modification could not improve the ability of asphalt mixtures to resist thermal cracking, evaluated at −18°C.

A Comparative Evaluation of The Mechanical Properties of PET and Polystyrene Modified Asphaltic Concrete Containing Rice Husk Ash Filler.

The study evaluated and compared the influence of bitumen modification for sustainable as- phalt using waste plastic (Polyethylene Terephthalate, PET) and waste Polystyrene (PS) at 5–50% modification levels. Rice husk ash (RHA) and desilted sand were used as filler and fine aggregate with crushed granite as coarse aggregate. Tests conducted include; penetration, viscosity, flash point, fire point, specific gravity, ductility and marshal stability test on asphalt. For PET modi- fied-binder a decrease in penetration and ductility was observed while the specific gravity, vis- cosity, flash and fire points of the binder increased. For the PS modified-binder, the penetration, ductility, viscosity and specific gravity decreased with an increase in PS while the flash and fire point increased. Marshall Stability results showed an optimal of 20% PET modification was ade- quate for medium traffic surfaing with stability, flow, density, air void, void in mineral aggregates (VMA), and Void filled with binder (VFB) of 4875N, 3.53 mm, 2.460 g/cm3, 3.30%, 18.20%, and 81.87% respectively. For 10% PS modification content, the stability, flow, density, air void, void in mineral aggregates (VMA), and Void filled with binder (VFB) were found to be 6825N, 3.33 mm, 2.362 g/cm3, 4.52%, 18.21%, and 75.18% respectively which was found to be adequate for heavy traffic surfacing. Hence, it was concluded that the investigated waste plastics could be used in Asphalt pavement courses. If applied, these results could provide low-cost materials for paving roads while also reducing waste-related pollution and environmental issues.

Surface Modification of Polystyrene with Boronic Acid for Immunoaffinity-Based Cell Enrichment.

Obtaining an enriched and phenotypically pure cell population from heterogeneous cell mixtures is important for diagnostics and biosensing. Existing techniques such as fluorescent-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) require preincubation with antibodies (Ab) and specialized equipment. Cell immunopanning removes the need for preincubation and can be done with no specialized equipment. The majority of the available antibody-mediated analyte capture techniques require a modification to the Abs for binding. In this work, no antibody modification is used because we take advantage of the carbohydrate chain in the Fc region of Ab. We use boronic acid as a cross-linker to bind the Ab to a modified surface. The process allows for functional orientation and cleavable binding of the Ab. In this study, we created an immunoaffinity matrix on polystyrene (PS), an inexpensive and ubiquitous plastic. We observed a 37% increase in Ab binding compared with that of a passive adsorption approach. The method also displayed a more consistent antibody binding with 17 times less variation in Ab loading among replicates than did the passive adsorption approach. Surface topography analysis revealed that a dextran coating reduced nonspecific antibody binding. Elemental analysis (XPS) was used to characterize the surface at different stages and showed that APBA molecules can bind upside-down on the surface. While upside-down antibodies likely remain functional, their elution behavior might differ from those bound in the desired way. Cell capture experiments show that the new surface has 43% better selectivity and 2.4-fold higher capture efficiency compared to a control surface of passively adsorbed Abs. This specific surface chemistry modification will allow the targeted capture of cells or analytes with the option of chemical detachment for further research and characterization.

Liquid-assisted grinding enables a direct mechanochemical functionalization of polystyrene waste.

The plastic waste crisis has grave consequences for our environment, as most single-use commodity polymers remain in landfills and oceans long after their commercial lifetimes. Utilizing modern synthetic techniques to chemically modify the structure of these post-consumer plastics (e.g., upcycling) can impart new properties and added value for commercial applications. To expand beyond the abilities of current solution-state chemical processes, we demonstrate post-polymerization modification of polystyrene via solid-state mechanochemistry enabled by liquid-assisted grinding (LAG). Importantly, this emblematic trifluoromethylation study modifies discarded plastic, including dyed materials, using minimal exogenous solvent and plasticizers for improved sustainability. Ultimately, this work serves as a proof-of-concept for the direct mechanochemical post-polymerization modification of commodity polymers, and we expect future remediation of plastic waste via similar mechanochemical reactions.

Photostabilization, Thermodynamic and Theoretical Studies of polystyrene by some 2-amino pyridine

Polystyrene (PS) films are photostabilized by 2-amino pyridine derivative compounds. Investigations were conducted on compounds of (a-e). The casting method was used to create PS films with complexes present in concentrations of 0.5 % by weight, while chloroform served as the solvent. By keeping track of the carbonyl indices as the exposure duration progressed, the photostabilization activities of these compounds were discovered. Using chloroform as a solvent, the variations in PS’s viscosity average molecular weight with exposure time were also monitored. The theoretical results of the PS modification compounds showed that the total energy values ​​of PS-D are higher energy content than the rest of the studied models. The negative sign in the HOMO energy indicates stability, that is, it is less effective, where values ​​are shown (HOMO) PS-C is the least effective (stable) and PS-E is the most effective (unstable). The thermodynamic theoretical outcome was shown that all reactions are endothermic and spontaneous, and the results of the (energy gap) values ​​gave a range from 2.38453 eV for PS-C to 2.60277 eV. For PVC-E, which proves that all PS modifications are conductive or semiconducting materials for electricity. HIGHLIGHTS Chemicals with 2-amino pyridine derivatives were used to study the photostabilization of PS films. For PS films, these chemicals function effectively as photostabilizers. These supplements Through UV absorption or screening, FTIR spectra, weight loss, and optical microscopy, the PS films are stabilized. According to the aforementioned processes and photostability, compound (a) was found to be the most effective in the photostabilization process. The use of molecules (a-e) that are 2-amino pyridine derivatives is encouraged by these mechanisms GRAPHICAL ABSTRACT

Fabrication of negatively charged nanofiltration membrane of modified polystyrene intercalated graphene oxide for pervaporation desalination

Polystyrene intercalated graphene oxide (GO) membranes with and without sulfonation were successfully prepared for pervaporation desalination applications. The membrane was deposited on nylon support and linked with Zn2+ (c) as a crosslinker. To improve membrane performance, modification of polystyrene via sulfonation was also carried out to convert polystyrene (PS) into polystyrene sulfonic acid (PSSA). The interlayer spacing (d-spacing), hydrophilicity, and stability were observed as the membrane characteristics which greatly influenced the desalination performance. Experimental results show that intercalation of GO with PS and PSSA increases the interlayer spacing and membrane stability. The addition of PS decreased the hydrophilicity of the membrane, while the addition of PSSA increased the hydrophilicity. Calculations for optimizing desalination using Central Composite Design (CCD) on c-PSSA-GO/Nylon membranes show that the optimum temperature and time can be achieved at 57 °C and 71 min. The c-PSSA-GO/Nylon membrane showed the best results with a NaCl rejection value of > 99% and a water flux of 15.56 ± 0.6 kg m-2h−1, which was applied to 1% NaCl feed. The c-PSSA-GO/Nylon membrane also shows consistent NaCl rejection and water flux when applied for an extended period. So, the c-PSSA-GO/Nylon membrane has excellent potential for pervaporation desalination.

Quasi-Static tensile loading performance of Bonded, Bolted, and hybrid Bonded-Bolted Carbon-to-Carbon composite Joints: Effect of recycled polystyrene nanofiber interleaving

Although hybrid bolted/bonded (HBB) joints possess each joint technique's benefits, the adhesive layer performance significantly affects the load-carrying capacity of hybrid joints. Nanofiber interleaving has become an efficient solution to improve the adhesion performance of bonded and HBB joints. This paper reveals the effectiveness of polystyrene (PS) nanofibers interleaving on the mechanical properties of adhesively bonded and HBB single lap joints (SLJs). For this purpose, PS nanofibers are produced via electrospinning from wasted polymers as a nature-friendly implementation. The PS nanofiber mats were interleaved between adherends as a reinforcement layer, and specimens were tested under quasi-static tensile loading. A significant improvement was seen in the peak load value of 10% for the HBB joint, and the fracture energy of the bonded joint increased by 15% with PS nanofiber modification. The failure modes of PS-reinforced specimens developed as more gradually progressive compared to neat specimens thanks to the compatibility of the recycled PS nanofiber with the epoxy and improved adhesive layer performance with PS modification. Furthermore, the morphological analyses of post-fracture specimens were monitored to realize the damage and nano-toughness mechanisms.

Circular Design and Functionalized Upcycling of Waste Commodity Polystyrene via C-H Activation Using Microwave-Assisted Multicomponent Synthesis.

The inefficient reuse and recycling of plastics-and the current surge of medical and take-out food packaging use during the pandemic-have exacerbated the environmental burden. This impels the development of alternative recycling/upcycling methods to pivot toward circularity. We report the use of the Mannich three-component coupling reaction for the modification of polystyrene (PS) recovered with a 99.1% yield from waste food containers to form functionalized nitrogen and oxygen-rich PS derivatives. A series of functionalized PS with increasing moles of formaldehyde (F) and morpholine (M) (0.5 × 10-2, 1.0 × 10-2, and 2.0 × 10-2 mol) was achieved using a sol-gel-derived Fe-TiO2 catalyst in a solvent-free, microwave-assisted synthesis. Modified polymers were characterized with viscometry, 1H NMR, 13CNMR (DEPT) FTIR, XPS, UV, and TGA. Functionalization scaled with an increasing ratio, validating the 3CR approach. Further functionalization was constrained by a competing oxidative degradation; however, the varying hydrogen bond density due to nitrogen and oxygen-rich species at higher ratios was shown to compensate for molecular weight loss. The integration of the N-cyclic quaternary ammonium cations exhibited the potential of functionalized polymers for ion-exchange membrane applications.

Impact of Aqueous Grafting of Polystyrene through Methacrylate-Modified Cellulose Nanofibrils on Emulsion Stabilization and Drying Behavior

Cellulose nanofibrils (CNFs) are abundant materials limited in application by their hydrophilic nature and fibrillar collapse during drying. Herein, hydrophobic CNFs (PS-MetCNFs) were produced via the grafting of polystyrene through a methacrylate handle on modified CNFs. This modification prevented fibrillar collapse of the CNFs upon drying with as low as 3.5 wt % polystyrene. System characterization through kinetics studies and controls revealed that a surfactant-free emulsion polymerization ran parallel to the grafting-through polymerization. Polystyrene on the PS-MetCNFs was both covalently bound and noncovalently bound. This noncovalently bound polymer was due to polymerization in the monomer-swollen polymer particles on the PS-MetCNF surface. The polystyrene modification interfered with CNF Pickering emulsion behavior, instead stabilizing monomer-swollen polymer particles entangled in the CNF network. Composites of PS-MetCNFs and poly(lactic acid) showed higher maximum tensile stress and modulus at 5 wt % loading relative to composites made with unmodified spray-dried CNFs, demonstrating a route to composite reinforcement with CNFs without energy-intensive spray drying.

Synthesis and characterizations of polystyrene materials with low dielectric constant and low dielectric loss at high frequency

AbstractIn this article, a facile and efficient approach to the modification of polystyrene (PS) materials with low dielectric properties at high frequency is reported. A series of N‐acetoxy amide (AA)‐containing polystyrenes (PSAAs) synthesized by free‐radical polymerization can be transformed into NCO‐containing polymers (rPSAAs) via Lossen rearrangement reaction of the AA group. The modified PS materials were then obtained by reacting the rPSAAs with hydroxyl‐terminated poly(phenylene oxide) (PPOD), polybutadiene, and amino‐terminated polysiloxane, respectively. The thermal stability, mechanical, and dielectric properties of PPOD‐modified PS materials were improved with increase of PPOD content. The PPOD (20 wt%)‐modified PS had a dielectric constant of 2.22 and dissipation factor of 1.65 × 10−3 at 10 GHz. This work provides an easy and effective method to prepare high performance modified PS materials by introducing poly(phenylene oxide), which could meet the requirement of new‐generation communication technology.

Synthesis of a magnetic polystyrene-supported Cu(II)-containing heterocyclic complex as a magnetically separable and reusable catalyst for the preparation of N-sulfonyl-N-aryl tetrazoles

In this work, a cost-effective, environmentally friendly, and convenient method for synthesizing a novel heterogeneous catalyst via modification of polystyrene using tetrazole-copper magnetic complex [Ps@Tet-Cu(II)@Fe3O4] has been successfully developed. The synthesized complex was analyzed using TEM (transmission electron microscopy), HRTEM (high resolution-transmission electron microscopy), STEM (scanning transmission electron microscopy), FFT (Fast Fourier transform), XRD (X-ray diffraction), FT-IR (Fourier transform-infrared spectroscopy), TG/DTG (Thermogravimetry and differential thermogravimetry), ICP-OES (Inductively coupled plasma-optical emission spectrometry), Vibrating sample magnetometer (VSM), EDS (energy dispersive X-ray spectroscopy), and elemental mapping. N-Sulfonyl-N-aryl tetrazoles were synthesized in high yields from N-sulfonyl-N-aryl cyanamides and sodium azide using Ps@Tet-Cu(II)@Fe3O4 nanocatalyst. The Ps@Tet-Cu(II)@Fe3O4 complex can be recycled and reused easily multiple times using an external magnet without significant loss of catalytic activity.

Sulfonium-Functionalized Polystyrene-Based Nonchemically Amplified Resists Enabling Sub-13 nm Nanolithography.

Nonchemically amplified resists based on triphenyl sulfonium triflate-modified polystyrene (PSTS) were prepared by a facile method of modification of polystyrene with sulfonium groups. The uploading of the sulfonium group can be well-controlled by changing the feed ratio of raw materials, resulting in PSTS0.5 and PSTS0.7 resists with sulfonium ratios of 50 and 70%, respectively. The optimum developer (methyl isobutyl ketone/ethanol = 1:7) is obtained by analyzing contrast curves of electron beam lithography (EBL). PSTS0.7 exhibits a better resolution (18 nm half-pitch (HP)) than the PSTS0.5 resist (20 nm HP) at the same developing conditions for EBL. This novel resist platform was further evaluated by extreme ultraviolet lithography, and patterning performance down to 13 nm HP at a dose of 186 mJ cm-2 with a line edge roughness of 2.8 nm was achieved. Our detailed study of the reaction and patterning mechanism suggests that the decomposition of the polar triflate and triphenyl sulfonium groups into nonpolar sulfide or polystyrene plays an important role in the solubility switch.

Gaseous- and Condensed-Phase Activities of Some Reactive P- and N-Containing Fire Retardants in Polystyrenes.

Polystyrene (PS) was modified by covalently binding P-, P-N- and/or N- containing fire-retardant moieties through co- or ter-polymerization reactions of styrene with diethyl(acryloyloxymethyl)phosphonate (DEAMP), diethyl-p-vinylbenzyl phosphonate (DEpVBP), acrylic acid-2-[(diethoxyphosphoryl)methylamino]ethyl ester (ADEPMAE) and maleimide (MI). In the present study, the condensed-phase and the gaseous-phase activities of the abovementioned fire retardants within the prepared co- and ter-polymers were evaluated for the first time. Pyrolysis-Gas Chromatography/Mass Spectrometry was employed to identify the volatile products formed during the thermal decomposition of the modified polymers. Benzaldehyde, α-methylstyrene, acetophenone, triethyl phosphate and styrene (monomer, dimer and trimer) were detected in the gaseous phase following the thermal cracking of fire-retardant groups and through main chain scissions. In the case of PS modified with ADEPMAE, the evolution of pyrolysis gases was suppressed by possible inhibitory actions of triethyl phosphate in the gaseous phase. The reactive modification of PS by simultaneously incorporating P- (DEAMP or DEpVBP) and N- (MI) monomeric units, in the chains of ter-polymers, resulted in a predominantly condensed-phase mode of action owing to synergistic P and N interactions. The solid-state 31P NMR spectroscopy, Scanning Electron Microscopy/Energy Dispersive Spectroscopy, Inductively-Coupled Plasma/Optical Emission Spectroscopy and X-ray Photoelectron Spectroscopy of char residues, obtained from ter-polymers, confirmed the retention of the phosphorus species in their structures.

Grafting on Polystyrene on Different Parts of the Molecule and Determination of Metal Uptake Thereby

α-Br-polystyrene (Br%7PS) and polystyrene p-acetyl chloride (Cl%5PS) were obtained by modification of polystyrene on its main chain and side groups using N-bromosuccinimide and acetyl chloride, respectively. The graft copolymers were prepared via atom transfer radical polymerization (ATRP) with Br%7PS and Cl%5PS as the macro-initiators, methacrylamide (MA) as monomer, 1,2-dipiperidinoethane as ligand, and CuBr as a transition metal compound. Characterization of the reaction products was done using Fourier transform infrared (FTIR) spectroscopy, H-1 proton nuclear magnetic resonance (1H-NMR) spectrometry and elemental analyses. According to the results of the structure characterization, the percentages of substitution of styrene units in the polystyrene were found to be 7.14% for Br%7PS and 5.21% for Cl%5PS by moles. The uptake properties of various metal ions by the polymers were investigated by an atomic absorption spectrophotometer (AAS).

Highly Efficient and para-Selective C-H Functionalization of Polystyrene Providing a Versatile Platform for Diverse Applications.

Postpolymerization modification of polystyrene (PS) can afford numerous value-added materials with different functions and applications, but it has been hampered by the lack of efficient methods. We report herein a highly efficient and para-selective conversion of the C-H bonds of the aromatic ring of PS into diverse functional groups using a combination of thianthrenation and thio-Suzuki-Miyaura coupling reaction. Notably, the thianthrenation efficiency of PS is as high as 99% and the degree of thianthrenation can be conveniently controlled using stoichiometric tuning of the amount of thianthrene-S-oxide added, resulting in 24-99 mol % thianthrenation. In the subsequent thio-Suzuki-Miyaura coupling reaction, 18 functionalized PS containing various functional groups (-CH2OH, -OMe, -SMe, -OTBS, -CH3, -NHBoc, -OCOMe, -CHO, -COMe, -Si(Me)3, etc.) were successfully prepared with a high degree of functionalization (64-99 mol %). The obtained functionalized PS can be readily converted into diverse functional materials, including solid-phase synthesis resins, aggregation-induced emission fluorophores, as well as ionomer binders and ion-exchange membranes for energy conversion devices. This method imparts diverse functionality onto PS with extremely high efficiency and selectivity, providing a versatile platform to transform existing commodity PS plastics into high-performance materials.

Polystyrene modification by cellulose derivative and organoclay

Polystyrene modification by cellulose derivative and organoclay

Preparation and Properties of Polystyrene Nanospheres Incorporated Cs3Bi2Br9 Halide Perovskite Disks

AbstractHalide perovskites are being in the focus of diverse research fields due to their attractive physicochemical properties. Herein, we present a strategy to prepare highly crystalline bismuth‐based halide perovskite disk, polystyrene nanospheres incorporated hybrid material and porous halide perovskite. After a proper surface modification of polystyrene, the halide perovskite was grown and crystallized around the sulfonated polystyrene via a facile solution processed synthesis and rapid solidification. By tuning the particle size of sulfonated polystyrene, a range of lead‐free hybrid materials was prepared. All the hybrid materials have good visible light absorption with an optical band gap of around 2.6 eV and variable photoluminescence properties. The incorporated sulfonated polystyrene could enhance the stability of halide perovskite in high humidity environments. Additional porous functionality could be brought to the halide perovskite materials through selective leaching of sulfonated polystyrene.

Modification of polymer thin film-coated metallic layer inside acid solutions

Modification of polystyrene (PS) thin film-coated copper (Cu) layer is studied by varying the PS layer thickness inside different acidic environments. PS-coated Cu films are exposed to acetic and hydrochloric acid environments and are investigated using UV–visible spectroscopy, atomic force microscopy, water contact angle and electrical measurements. Polymeric and metallic layer thicknesses are obtained from the X-ray reflectivity analysis. It is found that the metallic layer corrosion nearly follows an exponential decay with time and the decay time constant takes the higher values for the thicker PS films. The contact angle values, surface morphologies and in-plane current–voltage curves obtained from the films confirm that with increase in the acid concentration, corrosion of the metallic layer is much higher than the polymeric layer, as the in-plane current is reduced by a relatively higher value than the water contact angle. Penetration of the acid solution through intermolecular spacing or microscopic pores of the polymeric layer is the most probable reason for such corrosion of the metallic layer, but the removal of the polymeric layer is not favourable due to the hydrophobic effect.