Stability Of Polystyrene Research Articles

Development of a New Aggregation Method to Remove Nanoplastics from the Ocean: Proof of Concept Using Mussel Exposure Tests

The overproduction and mismanagement of plastics has led to the accumulation of these materials in the environment, particularly in the marine ecosystem. Once in the environment, plastics break down and can acquire microscopic or even nanoscopic sizes. Given their sizes, microplastics (MPs) and nanoplastics (NPs) are hard to detect and remove from the aquatic environment, eventually interacting with marine organisms. This research mainly aimed to achieve the aggregation of micro- and nanoplastics (MNPs) to ease their removal from the marine environment. To this end, the size and stability of polystyrene (PS) MNPs were measured in synthetic seawater with the different components of the technology (ionic liquid and chitosan). The MPs were purchased in their plain form, while the NPs displayed amines on their surface (PS NP-NH2). The results showed that this technology promoted a significant aggregation of the PS NP-NH2, whereas, for the PS MPs, no conclusive results were found, indicating that the surface charge plays an essential role in the MNP aggregation process. Moreover, to investigate the toxicological potential of MNPs, a mussel species (M. galloprovincialis) was exposed to different concentrations of MPs and NPs, separately, with and without the technology. In this context, mussels were sampled after 7, 14, and 21 days of exposure, and the gills and digestive glands were collected for analysis of oxidative stress biomarkers and histological observations. In general, the results indicate that MNPs trigger the production of reactive oxygen species (ROS) in mussels and induce oxidative stress, making gills the most affected organ. Yet, when the technology was applied in moderate concentrations, NPs showed adverse effects in mussels. The histological analysis showed no evidence of MNPs in the gill’s tissues.

Stabilization of polystyrene by styrylquinoline containing methacrylates

The thermostability of polysterene with/without new styrylquinoline containing methacrylic fragments has been described in the present work. Polystyrene and copolymers based on styrene and new methacrylic styrylquinoline containing monomers were synthesized by free radical thermoinitiated polymerization in the presence of 2,2′-azobisisobutyronitrile (1 wt%) as initiator at inert atmosphere. The impact of 2-[2-(4-methoxyphenyl)ethenyl]quinolin-8-yl 2-methylpropyl-2-enoate (М1), 2-(2-phenylethenyl)quinolin-8-yl 2-methylpropyl-2-enoate (М2), 2-[2-(4-nitrophenyl)ethenyl]quinolin-8-yl 2-methylpropyl-2-enoate (М3) on thermal stability of polystyrene was investigated. The thermostability of polystyrene and copolymers ST:M1, ST:M2, ST:M3 were studied by dynamic thermograviametric analysis. It was shown that destruction of polystyrene with corresponding units M1-M2 starts at 41–42°С higher, than reference polystyrene.

Aggregation and stability of sulfate-modified polystyrene nanoplastics in synthetic and natural waters

Nanoplastics (NPs) are becoming emerging pollutants of global concern. Understanding the environmental behavior of NPs is crucial for their environmental and human risk assessment. In this study, the aggregation and stability of polystyrene (PS) NPs were investigated under different hydrochemical conditions such as pH, salt type (NaCl, CaCl2, Na2SO4), ionic strength (IS), and natural organic matter (NOM). The critical coagulation concentrations of PS NPs were determined to be 158.7 mM NaCl, 12.2 mM CaCl2, and 80.0 mM Na2SO4. Ca2+ was more effective in destabilizing PS NPs, compared to Na+, owing to its stronger charge screening effect. In the presence of monovalent ions, NOM reduced aggregation through steric repulsion, whereas in the case of divalent ions, NOM induced aggregation through cation bridging. Initial and long-term stability studies demonstrated that, in waters with high IS and NOM content, NOM was the most significant factor affecting NPs aggregation. PS NPs would be highly suspended in all freshwaters, and even in wastewater, whereas they would aggregate rapidly and deposit in seawater. Finally, a statistical model was established to evaluate the hydrodynamic diameter of NPs in different waters. The results indicated the stability of PS NPs in natural aquatic environments and their potential for long-term transport.

Improvement in conductivity and thermal stability of polystyrene with two-step reduced graphene oxide based nanocomposite Graphene /polystyrene

In insitu microemulsion synthesis, we have synthesized successfully nanocomposite based on polystyrene (PS) and two-step reduced graphene oxide sheets with heat and NaBH4 agent after they had been treated by monoglyceride. Resulted Nanocomposite has been better in electrical conductivity (approximately 2,01 × 10-2S / cm), thermal stability (increased about 120 oC) and physical properties (glass transition temperatureincreasesof over 6.40 oC, elastic modulus increases by 45 %) than the pure PS properties.

Brominating of Oxyphenylimides for Enhancement of Stabilizing Properties of their Derivatives

New bromine-containing oxyphenylimides are synthesized by the Diels–Alder condensation from commercial products. The effect of the bromination of oxyphenylimides on their thermal behavior as comparing with the thermal stability of polystyrene in air is assessed by dynamic thermogravimetric analysis and differential scanning calorimetry. The bromination of oxyphenylimides has different influences on their thermal properties subject to the diene building. The perspectives of the usage of bromine-containing oxyphenylimides for the creation of new polystyrene-stabilizing systems are discussed.

Thermal Stabilizing Properties of Maleimidophenylmethacrylate Derivatives with Substitutes of Various Molecular Arhitectures in the Imide Cycle

Thermal oxidative degradation of polystyrene doped with maleimidophenylmethacrylate derivatives which are succinimidophenylmethacrylates with substitutes of various molecular architectures in the imide cycle has been studied by dynamic thermogravimetry in air. The doping monomers (0.5–7 mol.%) have been built into polystyrene macromolecular chains by means of the copolymerization reaction. Succinimidophenylmethacrylates containing spatially non-hindered double bonds or bulky substitutes in the amide cycle show both inhibiting and retarding effects. The m- or p-substitutes have practically identical effect on the polystyrene resistance. The increase of the dopant content up to 5 mol.% results in a regular increase of the thermal stability of polystyrene.

Photodegradation kinetics of poly( para-substituted styrene) in solution

The UV irradiation effects on stability of polystyrene, poly(4-methoxystyrene), poly(4-methylstyrene), poly(α-methylstyrene), poly(4- tert-butylstyrene), poly(4-chlorostyrene), and poly(4-bromostyrene) in dichloromethane, dichloromethane, tetrahydrofuran, and N, N-dimethylformamide solutions were studied in the presence of oxygen at different intervals of irradiation time. The photodegradation was studied at 293 K using fluorescence spectroscopy. Solutions of these polymers were accompanied by quenching of monomer and excimer emissions during the exposure of their solutions to UV light, and by a change in the structure of the fluorescence spectrum. Irradiation of poly(4-methylstyrene) and poly(α-methylstyrene) at excitation wavelength of 265 nm showed an increase of fluorescence intensity of a broad band, at longer wavelength without clear maxima. This may indicate that photodestruction of these polymers by irradiation with light of frequency absorbed by the polymer, may start from a random chain scission, with the possibility of formation of polyene and carbonyl compounds.

Maleimidophenylmethacrylates and their Derivatives as Polystyrene Thermal Stabilizers

Effects of maleimidophenylmethacrylates on thermal stability of polystyrene have been examined by dynamic thermogravimetric analysis in air conditions. The maleimidophenylmethacrylates with substitutes of various molecular architecture in imide cycle have been built in polystyrene macromolecular chains (as much as 1 mol %) by means of copolymerization reaction. The thermal stabilizing effects depend on the structure features of the used compounds. Some of the additives show the inhibiting effect only whereas other ones show combined inhibiting and retarding effects. The last ones revealed as very effective stabilizers of polystyrene against thermal oxidative degradation.

Stability of sulphonate type membranes in aqueous bromine/bromide environments

The effect of aqueous bromine/sodium bromide solutions on the stability of polystyrene and four different sulphonic acid based membranes has been investigated. It is shown that in the presence of these environments, the sulphonate groups that are directly bonded to the benzene rings are susceptible to rapid replacement by bromine, thus reducing the membrane performance, while the rate of degradation is critically dependent on the activity of free bromine. This is dependent on the ratio of bromine to bromide and on temperature. The bulk of the investigation was completed using ATR-FTIR spectroscopy, however as the area of analysis is limited to the surface of the samples, fluorescence microscopy and spectroscopy was utilised to study a limited number of samples. These techniques clearly showed that degradation occurred through the thickness of the materials and is not limited to their surfaces. This result was shown to be the case for all membranes where the sulphonate group was directly bonded to the phenyl ring and it is proposed that degradation occurs via a substitution reaction mechanism, where the bromine present in solution acts as a Lewis acid. On the other hand, membranes where the sulphonate group is directly attached to a fluorinated linear chain, i.e. perfluorosulphonic acid type membranes, are stable in the bromine environment.

The Influence of UV-Irradiation on Polystyrene Modified by Poly(Vinyl Acetate)

The photochemical stability of polystyrene, PS, modified by small amount of poly(vinyl acetate), PVAC,(1–5% wt)has been investigated using Gel Permeation Chromatography(GPC). Photocrosslinking process of PS with PVAC samples was studied by estimation of insoluble gel content. PVAC caused improvement of mechanical properties of PS but UV-irradiation leads to their fast deterioration. Results indicate that dispersion degree of modifying component has a significant influence on the course of photochemical reactions in polymer composition.

Surface-modified Zirconium Oxide Clusters and their Use as Components for Inorganic-Organic Hybrid Materials

ABSTRACTPre-formed transition metal oxide clusters with methacrylate ligands were polymerized in the presence of organic co-monomers to form inorganic-organic hybrid polymers. The number of polymerizable ligands and thus the crosslinking density of the hybrid polymers can be varied for a given cluster type by partially exchanging the methacrylate ligands for non-reactive ones. The properties of the hybrid polymers can also be varied by adjusting the conditions of the polymerization reaction, especially by a pre-polymerization procedure. It is shown that the thermal stability of polystyrene crosslinked by Zr6O4(OH)4(OMc)12 is thus greatly improved.

Thermal properties of polystyrene/group IIB dithizonate films

The effect of group IIB metal dithizone complexes on the properties of polystyrene have been investigated by GPC, FTIR, X-ray diffraction, TGA and DSC. The results of GPC and X-ray diffraction analysis proved that an improvement in the polymer chain ordered was achieved due to the presence of these complexes during the bulk polymerization of styrene monomer if compared with that of pure sample. TGA thermograms showed that the thermal stability of polystyrene is enhanced with increasing complex concentration. However, mercury gives the best results followed by cadmium and zinc dithizonate. DSC scans for the different polymer samples provides a further support to the TGA data.

Effect of Block Copolymer Adsorption on Thin Film Dewetting Kinetics

The stability of polystyrene (PS) films on silicon oxide is improved by blending with poly(styrene-block-methyl methacrylate) (PS-b-PMMA) having a short, adsorbing MMA block and long, dangling PS block (degree of polymerization N). Relative to PS (degree of polymerization P), hole growth velocity decreases by 5 and 17 times upon adding 0.05 volume fraction of PS-b-PMMA (φ) for N ∼ P and N ∼ 4P, respectively. In contrast to PS, holes approach a constant value and do not coalesce. The N ∼ 4P system provides better stabilization because of its broader interfacial width. For N ∼ P, hole velocity decreases as φ increases and then becomes constant for φ > 0.03. Relative to blends, holes grow faster in bilayers and eventually coalesce. AFM analysis shows that the PS hole floor is smooth whereas the blend floor contains patches. The film stabilizing effect of block copolymers can be attributed to a decrease in capillary driving force, entanglements at the matrix/copolymer interface, and brush grafting density.

On the possibility of “one-step’’ colouration and stabilization of polystyrene

Copolymers of styrene with an unsaturated benzanthrone dye, a triazinyl-2,2,6,6,-tetramethylpiperidine(TTMP) stabilizer and a combined in-one molecule dye and stabilizer, have been obtained. The influence of these additives on the rate of copolymerization and on the photostability of the copolymers was studied.

Colloidal stability of high-solids polystyrene and polyvinyl acetate latices

Commercial emulsion polymerization processes are often done with high-solids recipes (e.g., about 50 wt % monomer), resulting in relatively viscous, pseudoplastic reaction mixtures. The change in rheological behavior during high-solids emulsion polymerization complicates the operation in terms of imperfect mixing, increasing heat transfer resistance and reactor fouling. In this article, we report the influence of solids content on the colloidal stability of polystyrene (PS) and polyvinyl acetate (PVAc) latex systems. For the systems investigated, solids content up to 50 wt % had no influence on the colloidal stability of the latex. The influence of recipe on colloidal stability is more pronounced than the influence of operating conditions. Brownian coagulation dominates over shear coagulation for both low- and high-solids systems, although in some cases the operating conditions appear to have some effect on the course and outcome of high-solids emulsion polymerization.

Stabilization of polystyrene by Friedel-Crafts chemistry: effect of position of alcohol and the catalyst

Polystyrene has been copolymerized with 4-vinylbenzyl alcohol, 4-(2-hydroxyethyl)styrene, and 4-(3-hydroxypropyl)styrene and it has been shown that thermal cross-linking of these copolymers is dependent upon the alcohol content. When the alcohol content is low, no thermal cross-linking is observed. When various phosphate esters are present as catalysts with these low alcohol content copolymers, cross-linking is observed at temperatures of about 250°C but not at lower temperatures. Cross-linking enhances the thermal stability of the copolymers. Studies of the thermal stability of the copolymers and their blends with the catalysts have been performed using thermogravimetric analysis and thermogravimetric analysis coupled to Fourier transform infrared spectroscopy. There is little difference in the thermal stability of all three copolymers and their blends with the catalysts.

Stabilization of Polystyrene by Oligomeric UV Absorbers

Copolymers were prepared by the condensation reaction of formaldehyde and 2,4-dihydroxy benzophenone, 2-hydroxy-4-methoxy benzophenone and 2-hydroxy-4-butoxy benzophenone. The polystyrene films incorporated with these stabilizers were subjected to UV irradiation and then tested for any change in the carbonyl index, hydroxyl index, tensile strength, elongation at break and evaporation loss to evaluate the efficiency of the new stabilizers.

Thermal and photochemical stability of polystyrene and its blends with polyvinyl chloride

The influence of some irregularities in PS and PVC chains on their thermal stability was investigated. UV irradiation caused an increase in the content of these irregularities in the polymers. It was found that the presence of carbonyl groups and crosslinking of the polymer chains hamper the thermal dehydrochlorination of PVC and the total decomposition of both polymers. Weak peroxy linkages and conjugated double bonds decrease the temperature of total decomposition of PS and PVC blends

Effect of Triethanolamine and Benzaldehyde on the Storage Stability of Polystyrene- Ammonium Perchlorate Propellant

The effect of triethanolamine [102-71-6] and benzaldehyde [100-52-7] on the stability of polystyrene [9003-53-6] was studied by dynamic thermogravimetry (TG). Slower decompn. of polymer in the presence of these compds. indicates their inhibiting ability on the oxidn. of the polymer. The burning-rate measurements of polystyrene$/NH_4ClO_4$ propellants at ambient temp. and pressure increases with the storage time. The percentage change of the burning rate of the propellants contg. aldehyde and amine is less during the aging, which indicates the increased propellant stability. The safe-life time of the propellants for the ballistic stability was calcd. from the activation energy of the aging process with an Arrhenius equation. The safe-life of the propellants contg. triethanolamine and benzaldehyde is longer than that of the neat propellant.

Photo-oxidation stabilization of polystyrene by aromatic ultraviolet light absorbers forming charge transfer complexes

The aim of this work was to investigate the influence of UV light absorbing additives on the rate of ultra violet light initiated degradation of polystyrene (PS) in solutions. Anthracene (ANT), chloranil (CA) nitrobenzene (TNB) which can form cnarge transfer complexes between each other were used. It was found for illuminated PS-solutions by light of λ=254 nm that independently of the screening efficiency of these compounds, tne formed CT complexes ANT-CA and ANT-TNB cause a decrease of tne rate constant of degradation and of the value of the number average of chain scission S. This effect is due to the energy transfer from the excited polymer chain segments to the low energy triplets of these CT-complexes thus hindering the rection of polymer chain segments with oxygen leading to slowing down of photodegradation.