Phenylene Sulfide Research Articles

Evaluation of the Equilibrium Melting Temperature and Melting Behavior of Poly(Phenylene Sulfide) Crystals.

Focusing on the melting process of poly(phenylene sulfide) (PPS) crystals, one of the high-performance resins with a very wide range of applications, we attempted to clarify the melting process and derive the equilibrium melting temperature with structural analysis using X-ray scattering and thermal measurements. Two melting points were observed in the crystallized PPS films by DSC measurements. We focused on the low-temperature melting point, in situ small-angle and wide-angle X-ray scattering measurements using synchrotron radiation and DSC thermograms indicate the melting of microcrystals because of thickening of the amorphous part from small-angle X-ray scattering results. In addition, the Hoffman-Weeks plot based on the results of fast scanning calorimetry showed that the melting temperature is almost parallel to the straight line where melting temperature and crystallization temperature are equal, indicating that the melting is of a metastable structure. The melting point on the high temperature side was attributed to the melting of lamellar crystals. The equilibrium melting point was derived from the Hoffman-Week and Gibbs-Thomson plots as 318 °C.

Facile synthesis of telechelic poly(phenylene sulfide)s by means of electron-deficient aromatic sulfonium electrophiles.

We report the facile synthesis of telechelic poly(phenylene sulfide) (PPS) derivatives bearing functional groups at both termini. α,ω-Dihalogenated dimethyl-substituted PPS were obtained in high yield with a high degree of end-functionalization by using soluble poly(2,6-dimethyl-1,4-phenylenesulfide) (PMPS) and 4,4'-dihalogenated diphenyl disulfide (X-DPS, X = Cl, Br) as a precursor and an end-capping agent, respectively. Further end-functionalization is achieved through cross-coupling reactions; particularly, the Kumada-Tamao cross-coupling reaction of bromo-terminated telechelic PMPS and a vinylated Grignard reagent afforded end-vinylated PMPS with thermosetting properties. This synthetic approach can be applied to the preparation of various aromatic telechelic polymers with the desired structures and functionalities.

Comparison of the Thermal and Mechanical Properties of Poly(phenylene sulfide) and Poly(phenylene sulfide)-Syndiotactic Polystyrene-Based Thermal Conductive Composites.

Syndiotactic polystyrene (SPS) has attracted considerable attention recently due to its high melting temperature, low cost, and relatively low density value. The aim of the study is to reveal whether a blend of PPS and SPS (PPS-SPS) can be used instead of PPS for high thermal stability, high mechanical performance, and high thermal conductive material applications. For this aim, poly(phenylene sulfide)/syndiotactic polystyrene-based carbon-loaded composite materials were prepared using a twin screw extruder. Two carbon-based materials, carbon fiber (CF) and synthetic graphite (SG), were used to improve the mechanical properties and thermal conductivity of the PPS-SPS blends. Through-plane conductivity values of PPS-30SG-10CF and PPS-SPS-30SG-10CF were obtained to be 13.67 and 12.92 W/mK, with densities of 1.55 and 1.50 g/cm3, respectively. It was demonstrated that PPS-SPS blend-based carbon-loaded composites have great potential to be used in thermal management applications with the advantages of relatively low cost and lightweight compared to PPS-based composites.

Tribological properties of cyclic phenylene sulfide heat‐treated carbon fiber/polyphenylene sulfide composites

AbstractHigh‐performance self‐lubricating polyphenylene sulfide (PPS)/carbon fiber (CF) composites were obtained by treating the CF surface with heat‐treated cyclic phenylene sulfide oligomers (CPS). The influence of CPS treat conditions on the structure and properties such as mechanical and tribological performance of the composites were studied in detail. The results indicate that the PPS/CPS‐sized CF composites exhibit higher mechanical strength and better tribological performance than the PPS/original CF composites, especially under the condition of higher loads and speeds (300 N × 200 rpm and 200 N × 200 rpm). The performance enhancement is reasonably ascribed to the improved compatibility of the modified CF with the PPS matrix. Further structural analysis reveals that the modified CF treated at 300°C under N2(CF‐300N) has the most similar structure to the PPS matrix, which makes the comprehensive performances of PPS/CF‐300N composites superior to the products obtained under the other heat‐treatment conditions.

Highly Sulfonated Aromatic Graft Polymer with Very High Proton Conductivity and Low Hydrogen Permeability for Water Electrolysis

An aromatic graft polymer was synthesized for a proton exchange membrane (PEM) by grafting a highly sulfonated poly(phenylene sulfide sulfone) side chain onto a poly(arylene ether sulfone) main chain, thus creating a phase-separated morphology with cocontinuous channels of small hydrophilic ion domains. The graft PEM with the distinct hydrophilic/hydrophobic-separated morphology showed low hydrogen permeability while maintaining high proton conductivity. Along with durable dimensional, mechanical, and thermohydrolytic stabilities, the graft PEM showed effective properties for PEM water electrolysis (PEMWE). The graft PEM afforded a PEMWE performance of 6000 mA cm–2 at 1.9 V, which was 2.1-fold higher than that of N212, and showed a durable performance without loss for 50 h at a high current density (1000 mA cm–2).

Chain length effects of phenylene sulfide modifiers on selective acetylene partial hydrogenation over Pd catalysts

We recently reported that polymer chains with phenylene sulfide moieties can efficiently modify the Pd catalyst surface, enabling selective partial hydrogenation of acetylene under ethylene-rich conditions. In the present study, we synthesized oligomeric and polymeric phenylene sulfides with tailored molecular sizes to systematically investigate the catalytic effect of chain length of organic modifiers. The results showed that the increased chain length of the modifiers is beneficial for improving the acetylene partial hydrogenation selectivity by inhibiting adsorption and full hydrogenation of ethylene. This was attributed to the fact that modifiers with a greater number of sulfide groups per molecule can bind more efficiently to the Pd surface for entropic reasons (chelate effect) and thus better inhibit ethylene adsorption. In contrast, the adsorption of acetylene to Pd was nearly unaffected by the presence and size of the modifiers owing to its stronger binding ability and small kinetic diameter. Modifiers with larger chain lengths were also advantageous in improving long-term catalyst stability because of their higher thermochemical stability and greater ability to inhibit the formation of carbonaceous deposits. The present results showed that polymers can act as more efficient and long-lasting selectivity modifiers than commonly used small organic molecules.

Perfluorinated cyclo-tetrakis(phenylene sulfides): synthesis and structure

Perfluoro-cyclo-tetrakis(1,4-phenylene sulfide) has been synthesized by the reaction of tetrafluorobenzene-1,4-dithiol with perfluoro-1,4-bis(phenylthio)benzene. The reaction of tetrafluorobenzene-1,4-dithiol with perfluoro-m-xylene gives a macrocycle with 1,3- and 1,4-arrangement of bridged sulfur atoms.

Effective flow modifiers for high-filled poly(phenylene sulfide) composites based on chemical structure similarity

Polyphenylene sulfide (PPS) is one of the representative engineering plastics used for various applications in the automobile industry. In actual applications, fiber-reinforced polymers (FRPs) are used to ensure the enhanced performance of engineering plastics. However, during processing, high-filled polymer composites suffer from high viscosity and poor dispersion. In this study, we propose a method for reducing the melt viscosity of PPS composites. We synthesized a novel flow modifier using multicomponent polymerization (MCP) to achieve effective processability and superior compatibility with PPS. The prepared flow modifier, polyhexylbenzothioamide (PHBTA), exhibits enhanced compatibility with PPS due to similarities in the chemical structure (i.e. a thioamide group). Polyhexyl phenylacetamide (PHPA) is used as a reference demonstrating a poor compatibility with PPS. Furthermore, PPS/glass fiber (GF) composites containing PHBTA exhibit enhanced rheological properties, mechanical properties, GF dispersion, and an increase in the length of GFs in the fracture state. To better understand the mechanical properties of PPS/GF40/PHBTA composites, we predict their tensile moduli using the Mori-Tanaka theory and the Halpin-Tsai equation, and the predictions agree well with the experiment results. This study aims to improve flowability in PPS/GF40 composites, thereby ensuring the effective and low cost processing of polymers for practical applications. Moreover, this approach provides further insight into the rheological and mechanical properties of FRP composites.

Effect of activator/precursor mass ratio on sulfur-doped porous carbon for catalytic oxidation of aqueous organics with persulfate.

Sulfur-doped porous carbon has emerged as promising metal-free catalysts toward persulfate (PS) for catalytic oxidation of aqueous organics. Wherein, thermal pyrolysis with activator activation is very common for the preparation of activated carbon. However, the relationship between the mass ratio of activator/precursor and catalytic efficiency has been rarely reported. Herein, a series of sulfur-doped porous carbons (S-AC) were synthesized by one-step chemical activation of (Poly(phenylene sulphide) (PPS)) with K2CO3 as activator at K2CO3/PPS mass ratio ranging from 0 to 3. The effects of K2CO3/PPS mass ratio on its physicochemical properties and its catalytic performance for p-chlorophenol (PCP) degradation with PS were comprehensively investigated. Experiment results show that sulfur doping enhanced its catalytic activity and the sample synthesized with K2CO3/PPS mass ratio of 2 (S-AC-2) exhibited the best adsorption and catalytic performance toward PS for PCP removal. More importantly, S-AC-2 with PS could efficiently degrade various aqueous toxic organics other than PCP, and S-AC-2 showed superior catalytic activity to many recently reported advanced materials. In addition, the effects of several operate parameters, including reaction temperature, PS concentration, pH, humic acid, and inorganic ions on PCP oxidation were evaluated. By combining with the results of quenching experiments and EPR, the PS activation mechanism over S-AC-2 was revealed. Moreover, the reusability and regenerability of S-AC-2 was also studied. It indicates that S-AC-2 showed inferior reusability, but the catalytic activity of which could be fully recovered through thermal treatment at 600°C for 2h in N2.

Transcending the Trade-off in Refractive Index and Abbe Number for Highly Refractive Polymers: Synergistic Effect of Polarizable Skeletons and Robust Hydrogen Bonds.

High-refractive-index polymers (HRIPs) are attractive materials for the development of optical devices with high performances. However, because practical components and structures for HRIPs are limited from the viewpoint of synthetic techniques, it has proved difficult using traditional strategies to enhance the refractive index (RI) of HRIPs to more than a certain degree (over 1.8) while maintaining their visible transparency. Here, we found that poly(phenylene sulfide) (PPS) derivatives featuring both methylthio and hydroxy groups can simultaneously exhibit balanced properties of an ultrahigh RI of n D = 1.85 and Abbe number of νD = 20 owing to the synergistic effect of high molar refraction and dense intermolecular hydrogen bonds (H-bonds). This brand new strategy is anticipated to contribute to the development of HRIPs displaying ultrahigh RI with adequate Abbe numbers beyond the empirical n D-νD threshold, which has not been achieved to date.

Mechanical performance of Continuous/Short carbon Fiber-Reinforced Poly(phenylene sulfide) composites

A method for improving the fracture resistance and mechanical strength behavior of polymer composites by incorporating short carbon fibers into continuous fiber/poly(phenylene sulfide) laminate was explored in this manuscript. This method involves the incorporation of short carbon fibers into continuous carbon fiber thermoplastic laminates, by using the hot compression molding technique. Characterization of a continuous and discontinuous carbon fiber composite material with poly(phenylene sulfide) matrix (S-CCF/PPS laminate) was performed by using tensile, V-Notched Iosipescu, combined load compression and impulse excitation tests. According to the found results for this composite material, it was observed that the tensile strength and the elastic modulus values were 41% and 48% lower than a composite reinforced only by continuous fiber, respectively. The shear strength of the mixed material was found to be 32% lower than a continuous carbon fiber composite. These results were expected since it was used a combination of 50% of continuous and 50% of short carbon fiber, in volume. However, the compression strength of the mixed composite was found to be only 11.9% lower than a laminate reinforced with solely continuous carbon fiber, showing a synergic gain in this case. In addition, the impulse excitation results show that the material mechanical properties are within the expected range, but a high dispersion of the values was observed due probably to the random nature of the discontinuous fiber. Furthermore, it was observed that the failure modes for the composite evaluated in this work are similar to those found for composites processed only with continuous reinforcements and that the models used during the simulations presented similar results to what was found experimentally.

Investigations on the Creation of Promising Antifriction Polymeric Materials Based on Thermally Resistant Thermoplastics

The present review highlights the results of tribological studies on highly thermally resistant partially crystalline (Victrex poly(ether ether ketone) and poly(phenylene sulfide)) and amorphous (poly(arylene ether ketone)s) thermoplastics, which are promising for the creation of new antifriction materials that would be able to operate reliably under extreme conditions.

High-Sensitivity Fiber-Optic Low-Frequency Acoustic Detector Based on Cross-Correlation Demodulation

Fiber-optic acoustic sensors based on Fabry-Perot (F-P) interference structure have advantages of compact structure, high sensitivity, convenience to manufacture and immunity to electromagnetic interference. To simplify the demodulation system of the fiber-optic F-P sensor and reduce the demodulation cost, a low-frequency acoustic detector based on the principle of optical cross-correlation (OCC) demodulation is proposed. A fiber-optic F-P interference sensor based on the phenylene sulfide (PPS) diaphragm is used as a low-frequency acoustic detection unit. The OCC demodulation system of the F-P acoustic sensors mainly includes a superluminescent diode (SLED), a flat glass wafer and single-mode fibers. The flat glass wafer is used as the static correlation reference cavity of the PPS diaphragm-based F-P acoustic sensor. The experimental results show that the detector is responsive to low-frequency acoustic waves from below 20 Hz to 250 Hz. For the acoustic waves with a frequency of 20 Hz, the minimum detection limit (MDL) of sound pressure is 0.65 mPa. The detector has the potential for low-cost and high-sensitivity acoustic detection for applications such as infrasonic detection and photoacoustic gas detection.

Effect of activation time on sulfur-doped porous carbon for efficient degradation of organic pollutants with persulfate

Metal-free catalysis by using carbonaceous materials has propelled to the forefront in investigation of persulfate (PS) activation for green degradation of aqueous organic pollutants. Herein, sulfur-doped porous carbons (S-AC) were feasibly produced by chemical activation of Poly (phenylene sulphide) with KOH as activator. The influences of activation time on the porous structure, sulfur doping level, and chemical functionality of the as-prepared carbons were investigated by various characterization means. The S-AC samples were employed as metal-free catalysts to activate PS for phenol removal. Experiments results demonstrated that sulfur doping enhanced the catalytic activity of S-AC, and the S-AC-2 sample prepared by carbonization activation of 2 h was demonstrated to be a promising alternative to common metal oxides and other advanced carbon-based materials. Moreover, the S-AC-2/PS system could efficiently degrade various organics, which can be a green material for wastewater treatment and environmental remediation. In addition, the effects of various reaction parameters on phenol removal were discussed. It was found that S-AC-2 still presented an outstanding performance in a wide pH range. Furthermore, the PS activation mechanism over S-AC-2 was investigated by a series of classical radical quenching tests, EPR and Linear Sweep Voltammetry.

Insights into the luminescent properties of poly(phenylene sulfide)-grafted metal-organic framework (Tb–MOF–PPS) copolymers

In this study, a novel poly(phenylene sulfide)-grafted metal-organic framework (Tb–MOF–PPS) was fabricated. Initially, 2,5-dichloroterephthalic acid and TbCl3·6H2O were used as raw materials to synthesize the dihalogenated MOF (Tb–MOF) through ultrasound irradiation and hydrothermal methods. Subsequently, Tb–MOF was added at different mole proportions (2.5, 5, 7.5, and 10%) for the copolymerization of PPS, and a serial of Tb–MOF–PPS composites were successfully obtained. Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy proved that the Tb–MOF was covalently connected to PPS. The introduction of the Tb–MOF had no evident influence on the thermal properties of the composites. Additionally, the fluorescence characteristics revealed that the fluorescence excitation and emission spectra of the composites had a large redshift compared with that of PPS and possessed visible-light photoluminescence properties. These results indicate that the composites obtained can be used as optical sensors.

Investigation of the Synergistic Effect of Addition the Hybrid Carbon Fiber, Graphene Nanoplatelet and Matrix Modifier to Poly(phenylene sulphide) on Physical Properties

Investigation of the Synergistic Effect of Addition the Hybrid Carbon Fiber, Graphene Nanoplatelet and Matrix Modifier to Poly(phenylene sulphide) on Physical Properties

End-Groups of Poly(p-phenylene sulfide) Characterized by DNP NMR Spectroscopy

End-Groups of Poly(<i>p</i>-phenylene sulfide) Characterized by DNP NMR Spectroscopy

The Effect of Surface Substrate Treatments on the Bonding Strength of Aluminium Inserts with Glass-Reinforced Poly(phenylene) Sulphide.

Materials composed of a polymer matrix reinforced with carbon/glass fibres providing lightweight and superior mechanical properties are widely used as structural components for automotive and aerospace applications. However, such parts need to be joined with various metal alloys to obtain better mechanical performance in many structural elements. Many studies have reported enhancements in polymer–metal bonding using adhesives, adhesive/rivet combined joints, and different surface treatments. This study investigated the influences of various surface treatments on the adhesion between glass-reinforced poly(phenylene) sulphide (PPS) and aluminium alloy during the injection over-moulding process. Adhesion strength was evaluated via the shear test. Correlations for the shear strength of the polymer–metal with different metal–substrate treatments were studied. Since the strongest bonding was attained in the treatment with the highest roughness, this value, as it determines the level of micromechanical interlocking of connected materials, seems to be a critical factor affecting the adhesion strength. Three-dimensional (3D) topographic images characterized with a 3D optical microscope indicated that there was a meaningful influence exerted by the interface topologies of the aluminium substrates used for the over-moulding process. The results further indicated that increases in a substrate’s surface energy in connection with atmospheric plasma treatments negatively influence the final level of the bonding mechanism.

Thermal properties and hydrophilicity of antibacterial poly(phenylene sulfide) nanocomposites reinforced with zinc oxide-doped multiwall carbon nanotubes

Thermal properties and hydrophilicity of antibacterial poly(phenylene sulfide) nanocomposites reinforced with zinc oxide-doped multiwall carbon nanotubes

Surface Modification of Sulfur-Assisted Reduced Graphene Oxide with Poly(phenylene sulfide) for Multifunctional Nanocomposites.

The sulfur on the sulfur-assisted reduced graphene oxide (SrGO) surface provides the origin of poly(phenylene sulfide) PPS-grafting via SNAr mechanism. In-situ polymerization from sulfur on SrGO afforded surface modification of SrGO, resulting in enhanced dispersibility in PPS. The tensile strength, electrical and thermal conductivities, and flame retardancy of PPS-coated SrGO were efficiently enhanced using highly concentrated SrGO and masterbatch (MB) for industrial purposes. Three-dimensional X-ray microtomography scanning revealed that diluting MB in the PPS resin afforded finely distributed SrGO across the PPS resin, compared to the aggregated state of graphene oxide. For the samples after dilution, the thermal conductivity and flame retardancy of PPS/SrGO are preserved and typically enhanced by up to 20%. The proposed PPS/SrGO MB shows potential application as an additive for reinforced PPS due to the ease of addition during the extrusion process.