Pure Polyphenylene Sulfide Research Articles

Anticorrosion composite coating based on silver phosphate/poly-phenylene sulfide with excellent hydrophobicity and antimicrobial properties

Combating microbial contamination has been one of the hottest topics in the scientific community. Therefore, antibacterial materials have been rapidly developed and widely used in recent decades. However, developing corrosion-resistant coatings with both hydrophobic and antimicrobial properties remains challenging. This study innovatively mixed polyphenylene sulfide (PPS) resin with Ag3PO4/SiO2 filler, and prepared a hydrophobic antibacterial coating with enhanced corrosion resistance on the tinplate surface through a simple spraying strategy. After testing, the water contact angle of the composite coating is 139.7° ± 1°, and the sliding angle is less than 5° ± 1°. Compared with the pure PPS coating, the corrosion current of the composite coating was reduced by 4 orders of magnitude, with an impedance of 788740 Ω·cm2. After 200 h testing in a salt spray chamber, it still showed excellent corrosion resistance. Excellent hydrophobicity and anti-corrosion properties effectively reduce the adhesion of water, thereby preventing microorganisms from forming biofilms on the coating surface and corroding the substrate. In addition, bacterial tests show that the coating has excellent antibacterial efficacy, effectively inhibiting the reproduction of E. coli and S. aureus, providing a second line of defense to prevent bacteria from adhering to the substrate. Therefore, the multi-faceted characteristics make PPS composite coatings have broad application prospects.

Development of high-flowability melt PPS-based composites through blending with g-C3N4

Polyphenylene sulfide (PPS), commonly used as a core material for high-temperature flue gas treatment, exhibits elevated viscosity when processed even at temperature exceeding 280 °C. In this study, a novel high-flowability PPS-based composite was fabricated through the incorporation of graphitic carbon nitride (g-C3N4) via a well-established melt extrusion procedure. The enhancement of flowability in PPS was verified, and the material's texture structures and fundamental properties of composites with varying contents were determined. The composites exhibit well-dispersed g-C3N4, a significant reduction in shear viscosity (>10 %), a notable increase in melt index (>30 %), improved crystallinity, and comparable or superior performance compared to pure PPS. When the g-C3N4 was introduced into the PPS matrix, a phase-separated composite structure was formed. This structure reduces the entanglement degree between the PPS molecular chains and provides more space for free-movement of the PPS chains, and thus the improvement in flowability for the composites can be clearly demonstrated. Therefore, g-C3N4 can be used as a novel flow modifier to enhance the flowability and stability of PPS resin without compromising its fundamental properties, which offers significant prospects for improving productivity, optimizing energy usage, and managing costs for PPS-based products.

Preparation, characterization, and in vitro biological evaluation of salicylic acid‐modified polyphenylene sulfide/quartz fiber/hydroxyapatite composite with high mechanical property for bone replacement

AbstractThe surface inertness of pure polyphenylene sulfide (PPS) limits its application in orthopedic implant materials. On that basis, modified PPS containing hydroxyl and carboxyl groups, that is, SAPPS was synthesized by nucleophilic substitution of dihalide monomers and sodium sulfide under high pressure. And consequently, a kind of ternary composite consisting of polyphenylene sulfide salicylate/quartz fiber/hydroxyapatite (SAPPS/QF/HA) was developed. The structure, composition, cross section morphology, degradation behavior, mechanical property, and biological property of all the composites were characterized by Fourier transform infrared spectroscopy, x‐ray diffraction, differential scanning calorimetry, thermogravimetric analyzer, scanning electron microscope, energy dispersive spectrometer, and in vitro cytocompatibility tests. The composites exhibited good thermal property, which achieved a high melting point (277.8°C) and decomposition temperature (493.9–502.7°C at 5% weight loss). When the mass fraction of 20 wt% QF and 20 wt% HA was added in the pure SAPPS, the bending yield strength and bending modulus of the composite (SAPPS/20QF/20HA) were 177.4 MPa and 8.03 GPa, respectively, which increased by 61.6% and 158.2% compared with that of the pure SAPPS. Observing the considerable proliferation and adhesion of mouse bone marrow mesenchymal stem cells (mBMSCs) in the experiment, we demonstrated that the SAPPS and its composites were non‐toxic, and the SAPPS/QF/20HA composites had the most prominent effect in promoting the proliferation and adhesion of mBMSCs.Highlights Salicylic acid‐modified polyphenylene sulfide was studied as a biomaterial. The composite material has mechanics matching with human cortical bone. Cell experiments showed that all materials were nontoxic.

Improving Mechanical and Barrier Properties of Antibacterial Poly(Phenylene Sulfide) Nanocomposites Reinforced with Nano Zinc Oxide-Decorated Graphene

Nano zinc oxide-decorated graphene (G-ZnO) was blended with polyphenylene sulfide (PPS) to improve its tensile, thermal, crystalline, and barrier properties. The properties of neat PPS and PPS/G-ZnO nanocomposites were characterized and compared using various tests, including tensile tests, scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, evaluation of Escherichia coli inhibition, and barrier performance. The results demonstrated that G-ZnO played a crucial role in heterogeneous nucleation and reinforcement. When the concentration of G-ZnO was 0.3%, the tensile strength, elongation at break, thermostability, crystallinity, and water vapor permeability coefficients (WVPC) approached their maximum values, and the microscopic morphology changed from the original brittle fracture to a relatively tough fracture. In addition, when G-ZnO was added to PPS at a ratio of 0.3%, the tensile strength, elongation at break, and WVPC of PPS were increased by 129%, 150%, and 283%, respectively, compared to pure PPS. G-ZnO endowed the nanocomposites with antibacterial properties. The improvement in barrier performance can be attributed to three reasons: (1) the presence of G-ZnO extended the penetration path of molecules; (2) the coordination and hydrogen bonds between PPS polymer matrix and G-ZnO nanofiller narrowed the H2O transmission path; and (3) due to its more hydrophobic surface, water molecules were less likely to enter the interior of PPS/G-ZnO nanocomposites. This study provides valuable insights for developing high-performance PPS-based nanocomposites for various applications.

Effects of modified palygorskite on performance, crystallization and rheology of polyphenylene sulfide

In this work, Pal-Fe3O4 was prepared by magnetic modification of purified palygorskite (Pal), and then STAC@Pal-Fe3O4 was prepared by organic modification of Pal-Fe3O4 with Stearyl trimethyl ammonium chloride (STAC). The preparation conditions of STAC@Pal-Fe3O4 were optimized by orthogonal experiment. Some characterization results such as X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) showed that palygorskite had been successfully modified. In addition, STAC@Pal-Fe3O4/polyphenylene sulfide (PPS) nanocomposites were prepared by melt blending method. The mechanical properties, rheological properties and crystallization properties of STAC@Pal-Fe3O4/PPS nanocomposites were studied. When the mass fraction of STAC@Pal-Fe3O4 in PPS was 2.5 wt%, the tensile strength and impact strength of STAC@Pal-Fe3O4/PPS nanocomposites were 65.06% and 366% higher than those of pure PPS, respectively. Thermogravimetric analysis showed that STAC@Pal-Fe3O4 improved the thermal stability of PPS. The non-isothermal crystallization behavior of STAC@Pal-Fe3O4/PPS nanocomposites was studied by DSC method and Rheonaut technology for simultaneous rheology and FTIR, respectively. The results showed that STAC@Pal-Fe3O4 can significantly improve the crystallization rate and crystallinity of PPS. Rheological studies presented that STAC@Pal-Fe3O4 had strong compatibility with PPS.

Biological oyster shell waste enhances polyphenylene sulfide composites and endows them with antibacterial properties

To date, there is no research that deals with biological waste as fillers in polyphenylene sulfide (PPS). In this study, oyster shells were recycled and treated to prepare thermally-treated oyster shells (TOS), which were used as PPS fillers to make new bio-based antibacterial composite materials. The effect of varying the content of TOS was studied by means of structure and performance characterization. PPS/TOS composites were demonstrated to have an antibacterial effect on the growth of E coli and S. aureus. Qualitative analysis showed that when the TOS content was ≥ 30% and 40%, the composite materials had an apparent inhibition zone. Quantitative analysis showed that the antibacterial activity increased with the TOS content. Fourier transform infrared spectroscopy indicated the formation of hydrogen bonds between the molecular chains of TOS and PPS and the occurrence of a coordination reaction. At 10% TOS, the composite tensile strength reached a maximum value of 72.5 MPa, which is 9.65% higher than that of pure PPS. The trend of bending properties is the same as that of tensile properties, showing that the maximum property was reached for the composite with 10% TOS. At the same time, the crystallinity and contact angle were the highest, and the permeability coefficient was the lowest. The fatigue test results indicated that for the composite with 10% TOS, the tensile strength was 23% lower than static tensile strength, and the yield strength was 10% lower than the static yield strength. The results of the study showed that TOS not only could reduce the cost of PPS, but also could impart antibacterial properties and enhance the mechanical and, barrier properties, the thermostability, as well as the crystallinity.

Impact strength enhancement of PPS polymer matrix by synthesis of nanocomposite with WS2, MoS2 nanofillers, and impact modifier PEGM

ABSTRACT Polyphenylene sulfide (PPS)-based nanocomposites have attracted attention in various automotive applications. The present study is aimed at improving the impact strength of PPS polymer using the addition of nanofiller tungsten disulfide (WS2), molybdenum disulfide (MoS2), and impact modifier poly(ethylene glycidyl methacrylate) (PEGM), prepared through melt compounding. Nanocomposite of PPS+20 wt.% PEGM+0.5 wt.% WS2 produced results with an impact strength of 134.82 J/m compared to pure PPS (50.98 J/m). PEGM composition is varied from 10 to 50 wt.% to test the effect on impact strength. The key outcome is a higher impact strength of a nanocomposite by using lower weight percentage additions of WS2 and MoS2.

Preparation, Crystallization Behavior, Simultaneous Spectroscopic and Rheological Characterization of Polyphenylene Sulfide/Graphene Quantum Dots Nanocomposites

AbstractGraphene quantum dots are prepared conveniently and quickly with brown‐black humic acid as raw material by green oxidation process. The average size of GQDs is about 12 nm with a lattice spacing of 0.26 nm and GQDs have hydroxyl and carboxyl functional groups on their surface. Moreover, photoluminescence testing shows that GQDs have excellent photoluminescence properties with maximum excitation/emission wavelength at 347/478 nm. Next, polyphenylene sulfide (PPS)/GQDs nanocomposites are prepared by melt blending with GQDs and PPS. Mechanical tests show that the tensile strength and the impact strength of PPS can be greatly improved when the amount of GQDs is 0.5 wt% and tensile strength and the impact strength are increased by 53.38% and 375%, respectively. The nonisothermal crystallization of PPS/GQDs nanocomposites is investigated by differential scanning calorimetry, which shows that GQDs effectively increase the crystallization rate of PPS. The crystallization of PPS/GQDs nanocomposites during cooling are studied by Rheonaut technology analysis. The rheological results show that the storage modulus of PPS/GQDs (0.5 wt%) nanocomposites is increased by about 1.04 times than that of pure PPS, and 2D IR spectrum confirms that GQDs accelerate crystallization of PPS. Rheological studies present that GQDs have good compatibility with PPS.

Effect of carbon nanotube on thermal, tribological and mechanical properties of 3D printing polyphenylene sulfide

Due to its high temperature (maintain stable performance at 200 ℃), corrosion resistance (resistant to strong acids and alkalis) and high mechanical strength, polyphenylene sulfide (PPS) has been attracting more attention in recent years, but research about PPS and 3D printing reinforced composites remains low. Pure PPS has lower application potential compared to its composites. In this study, carbon nanotube (CNT) reinforced PPS 3D printing filaments with uniform CNT dispersion were prepared and CNT uniformity was ensured by coating maleimide polymers (MIPs). Systematically analyzed CNT (contents between 0 and 0.9 wt%) effects on tribological, mechanical and thermal performance of 3D printing PPS. Compared to pure PPS, tensile and bending strengths increased 26% and 29%, respectively. Crystallinity of PPS printed parts improved through thermal conductivity and diffusivity. Wear rate reduced from 1.14E-3 mm 3 N −1 m −1 to 1.838E-5 mm 3 N −1 m −1 . Both fracture and worn surfaces were observed by SEM. As result, this research expects to improve engineering application values of 3D printing PPS. • Prepared carbon nanotube polyphenylene sulfide composite material for 3D printing. • A non-covalent method was used to realize carbon nanotube dispersion in printing filament. • Composite materials’ wear resistance and mechanical properties significantly improved. • Analyzed influence mechanisms of carbon nanotube performance.

In situ micro-fibrillization and post annealing to significantly improve the tribological properties of polyphenylene sulfide/polyamide 66/polytetrafluoroethylene composites

Self-lubricating polyphenylene sulfide (PPS)-based composites were achieved by in-situ construction of ordered polyamide 66 (PA) microfibrillar structure coupling with the addition of polytetrafluoroethylene (PTFE) powders as solid lubricants, using high shear injection moulding technique. The influence of annealing temperature on the in-situ formed PA microstructure and properties such as crystalline structure, mechanical as well as tribological performance of corresponding composites was studied in detail. Results suggested that PPS (56 wt%)/PA (24 wt%)/PTFE (20 wt%) composites exhibited the best tribological properties after annealing at 150 °C for 1h. The lowest friction coefficient and specific wear rate are as low as 0.139 and 4.372 × 10−6 mm3/Nm which are nearly 80% and 1.83 × 103 times lower than pure PPS, respectively. This work provides a facile method to reduce both friction and wear properties of self-lubricating thermoplastic polymers which are critical for weight reduction and energy saving in industrial fields.

Application and Mechanical Properties of Polyphenylene Sulfide-Based Composite Organic Materials in Skull Repair

For the problem that the metal titanium mesh has major shortcomings in clinical skull repair, poly(lactideglycolide acid) (PLGA) was dissolved in 1,4-dioxane and it was mixed with nano-scale powdery hydroxyapatite (HA) to obtain HA/PLGA. Nano-scale HA/PLGA/PPS composite materials were obtained by the physical blending method and direct composite method with polyphenylene sulfide (PPS). First, the material characterization of SEM and TEM was carried out during the preparation of the material. The nano-HA/PLGA/PPS composite material was implanted into the skull of patients with large bone flap decompression. The skull was repaired with isolated bone flaps and shaped nanomaterials. X-ray images, histopathological tests, and polymerase chain reaction (PCR) analysis of genes related to osteogenic activity were performed on the repaired damaged skull of the patients. After the operation, the skeleton formed by the prepared material was tested for mechanical indexes such as bending resistance and stretching. The results showed that the particle size of the material produced by direct composite was better, and HA/PLGA can be uniformly filled into the PPS. Nano-HA/PLGA/PPS composite materials can improve the proliferation ability of MG-63 cells and promote the osteogenic differentiation of the cells. After implantation of the material, the bone tissue healed well after the skull defect, and the mRNA expression of osteogenic related genes (ALP, Colα(I), IGF-1, OC, TGF-β1) was significantly increased. Post-operational bending strength and tensile strength tests of the implanted repaired skull skeleton show that compared with pure PPS, the addition of HA/PLGA material can increase the rigidity of the material.

Preparation and characterization of polyphenylene sulfide/graphene nanoplatelets composite fibers with enhanced oxidation resistance

Composite masterbatches of polyphenylene sulfide (PPS) with functionalized graphene nanoplatelets (GNPs) were prepared by melt blending via a twin-screw extruder. The structure and morphology of composite masterbatches were characterized by scanning electron microscopy and X-ray diffraction analysis. The PPS/functionalized GNPs composite fibers were then manufactured by a self-made spinning equipment via melt spinning. The oxidation resistance and other properties of PPS composite fibers were also examined. The results showed that the pure PPS fibers exhibited smooth surface, whereas the surface of PPS/functionalized GNPs composite fibers was rough. The addition of functionalized GNPs could be acted as heterogeneous nucleating agents to improve the crystallization and increase the degree of crystallinity. The retention rate of breaking strength of PPS/functionalized GNPs composite fibers could maintain up to 85% after the oxidation treatment. The improvement in the oxidation resistance of PPS/functionalized GNPs composite fibers is the results of comprehensive effects characterized by the X-ray photoelectron spectroscopy analyses. The addition of functionalized GNPs could limit the damage of the C–S group and retard the generation of sulfuryl groups (–SO–) during the oxidation treatment. The chemical combination of the elements sulfur (S) and oxygen (O) could also be restricted, thus weakening the oxidation activity.

Fabrication of durable fluorine-free polyphenylene sulfide/silicone resin composite superhydrophobic coating enhanced by carbon nanotubes/graphene fillers

In this paper, a durable fluorine-free polyphenylene sulfide (PPS) composite superhydrophobic coating was fabricated by a simple spaying method. The low surface energy was provided by silicone resin (SiR) and the hierarchical structure was designed by reinforced fillers, carbon nanotubes/graphene (CNTs/RGO), which was allied by coupling agent of NH2-C3H6-Si(OC2H5)3 (KH-550). The best obtained coating possessed excellent superhydrophobic performance with the water contact angle (WCA) of (161 ± 1)° and sliding angle (SA) of (2 ± 1)°. Meanwhile, the final PPS/SiR/CNTs/RGO superhydrophobic coating exhibited favorable self-cleaning and anti-wear ability. After 5000 times friction, the wettability of that still maintained at WCA 139°, the weight loss of which was a fifth of the pure PPS coating. The improvement of mechanical stability was ascribed to the synergistic effect of SiR and CNTs/RGO. Thermogravimetric analysis (TGA) testified that the coating could be used in high temperature environment (320 ℃) for a long time. Simultaneously, the potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS) results indicated that the prepared coating possessed excellent anti-corrosion performance with lower corrosion current (1.47 × 10−8 A/cm2) and high protection efficiency (99.958%) even after 28 days immersion in 3.5 wt.% NaCl solution. From above, this durable PPS composite superhydrophobic coating could provide promising applications for industrial fields.

A Superhydrophilic and Anti-Biofouling Polyphenylene Sulfide Microporous Membrane with Quaternary Ammonium Salts

Polyphenylene sulfide (PPS) membranes were modified by chloromethylation and quaternary amination reaction to prepare a hydrophilic PPS microporous membrane. The structures of the modified PPS membranes were characterized by the use of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The results showed that the modified membranes maintain the same microporous structures as the PPS membrane. The hydrophilicity of the modified membranes was significantly improved compared to that of the PPS membranes, and the water flux of N-methylimidazole modified membranes, triethylamine modified membranes, and both mixture modified membranes achieved 110.475, 168.94, 150.59 L·m−2·h−1, respectively. The quaternary amination of the PPS membranes made much less bovine serum albumin (BSA) pollution accumulation on the top surface of the modified membranes, and there was a significant improvement, to 94%, in the BSA rejection rate. Most importantly, the antibacterial activity of the modified membranes was effectively improved, and the bactericidal rate was elevated to above 80% in comparison with pure PPS membranes, which was attributed to the introduction of quaternary ammonium salts and imidazolium salts in out-surface of the membranes.

Nonisothermal crystallization kinetics, morphology, and tensile properties of polyphenylene sulfide/functionalized graphite nanoplatelets composites

Polyphenylene sulfide (PPS)/graphite nanoplates (GNPs) nanocomposites were manufactured by simple melt compounding. The GNPs were first functionalized using synthesized benzimidazolium salt to improve the compatibility with PPS matrix. The functionalized GNPs showed an exfoliated dispersion in PPS matrix, which also could significantly improve the tensile properties of composites. Differential scanning calorimetry was used to investigate the nonisothermal crystallization kinetics of PPS/functionalized GNPs composites. The results showed that the PPS/functionalized GNPs composites always had a higher crystallization peak temperature ( Tc) than pure PPS resin at different cooling rates due to the addition of GNPs. The GNPs could also play the role of heterogeneous nucleating agents to accelerate the crystallization; however, at high content, they could also limit the mobility of PPS macromolecular chains and hinder the crystallization. The Mo equation could be used to analyze the nonisothermal crystallization kinetics, whereas the Ozawa equation was not suitable for the nonisothermal crystallization process. Consistent with a previous analysis, the results also showed that the addition of GNPs could also decrease the crystallization activation energy ( Ec) of PPS resin at low content while increasing the Ec at high content.

Effect of carboxylic polyphenylene sulfide on the micromechanical properties of polyphenylene sulfide/carbon fiber composites

The aim of this study was synthesis of the polyphenylene sulfide (PPS) containing carboxyl unit and investigation of the effect of modified PPS used as compatibilizer on the interfacial micromechanical properties of carbon fiber (CF) reinforced PPS composites. A series of copoly(1,4-phenylene sulfide)-poly(2,5-phenylene sulfide acid) (PPS-COOH)s containing different proportions of carboxyl units in the side chain were synthesized by the reaction of dihalogenated monomer and sodium sulfide via nucleophilic substitution polymerization under high pressure. According to the results of FT-IR, DSC, TGA, mechanical test and contact angle test, all of the copolymers were found to have analogous structure and improved hydrophilic property comparing with neat PPS. There was a good physical compatibility between the modified PPS and the pure PPS. The microbond test (measuring apparent interfacial shear strength (τapp) of the composite) and scanning electron microscopy (SEM) also showed that the optimized PPS-COOH (7.5) can be used to improve the micro-mechanical properties and interfacial bonding between CF and PPS matrix. The maximum τapp of 10%PPS-COOH (7.5)/PPS/CF composite was 49.1 MPa, which had increased 36.0% comparing with that of the pure PPS/CF composite (36.1 MPa).

Enhanced mechanical and thermal properties of CTAB-functionalized graphene oxide–polyphenylene sulfide composites

Polymer nanocomposites based on polyphenylene sulfide (PPS) and graphene oxide (GO) modified with cetyltrimethylammonium bromide (CTAB) were prepared. The properties of CTAB-modified graphene oxide (CGO) were investigated by Fourier transform-infrared spectroscopy, X-ray diffraction, and Raman spectroscopy. Results indicated that the ordered structure of GO was impaired by the introduction of CTAB and increased interlayer distance was found for CGO due to the intercalation of CTAB. Mechanical tests revealed that the tensile strength and Young’s modulus of 0.1 wt% CGO/PPS composite were 45.4% and 171.8%, respectively, higher than that of pure PPS matrix, which could be attributed to the entanglement of polymer chains between CTAB and PPS polymer chains. Dynamic mechanical analysis indicated that the glass transition temperature ( Tg) of PPS matrix was enhanced due to the addition of CGO and the Tg of 0.5 wt% CGO/PPS composite increased about 10°C higher than pure PPS. In addition, the thermal stability of PPS had significant improvement according to the results of thermogravimetric analysis. The residual mass of 0.5 wt% CGO/PPS composite at 800°C was 1.22 times higher than that of pure PPS.

Nonisothermal crystallization kinetics of polyphenylene sulfide composites based on organic clay modified by benzimidazolium salt

Polyphenylene sulfide (PPS)/organic clay nanocomposites were prepared by simple melt blending. A synthesized benzimidazolium salt was used to modify the sodium montmorillonite in order to improve the compatibility with the PPS. The nonisothermal crystallization kinetics of PPS/organic clay composites were investigated by differerntial scanning calorimetry(DSC). It was observed that the crystallization peak temperature of PPS/organic clay composites was higher than pure PPS at various cooling rates. Several models such as the Ozawa and Mo equation were used to characterize the nonisothermal cooling crystallization kinetics of the PPS/organic clay composites. The results indicated that the Ozawa equation was not successful, while the Mo equation was successful to describe the nanoisothermal ctystallization kinetics of PPS/organic clay nanocomposites. The results also indicated that organic clay not only served as heterogeneous nucleating agents for PPS crystallization at lower content but also restricted the mobility and diffusion of PPS chains at higher content. These results were further supported by the crystallization activation energy of the samples determined by the Kissinger method.

Modification of montmorillonite by different surfactants and its use for the preparation of polyphenylene sulfide nanocomposites

Polyphenylene sulfide (PPS)/clay composites were prepared by simple melt blending. Three different kinds of surfactants such as cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl benzene sulfonate (SDBS), and synthetic 1,3-dihexadecyl-3H-benzimidazolium bromide (Bz) were used as organic modifiers for the organic modification process. The benzimidazolium-modified montmorillonite (Bz-MMT) and CTAB-modified MMT (CTAB-MMT) exhibited larger interlayer spacing than SDBS-modified MMT (SDBS-MMT), while SDBS-MMT and Bz-MMT exhibited higher thermal stability compared with the CTAB-MMT. The morphology of the PPS/organic MMT nanocomposites was evaluated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The nanocomposites based on SDBS-MMT and Bz-MMT exhibited good overall dispersion of organic MMT with a mixed dispersion of intercalated and exfoliated structures. Differential scanning calorimetry and thermogravimetric analysis (TGA) were used to evaluate the thermal properties of PPS/organic MMT nanocomposites. The crystallization process of PPS in all nanocomposites was accelerated, and the crystallinity also increased, when compared with the pure PPS from the DSC analysis. The TGA analysis indicated that nanocomposites based on SDBS-MMT and Bz-MMT exhibited higher thermal stability than composites based on CTAB-MMT due to the well-dispersed nanoplatelets.

Superior Dielectric Performance of Engineering Thermoplastic as a Result of In situ Embedding of Nanoscale Mixed-Phase Molybdenum Oxide

To facilitate in situ generation of single and mixed-phase molybdenum oxide on the nanoscale in a network of polyphenylene sulfide (PPS), a novel polymer–inorganic solid-state reaction is proposed. Ammonium molybdate was homogeneously mixed with PPS in 1:1 molar ratio and heated at 285°C for different times (6 h, 24 h, or 48 h) under ambient conditions. The products were characterized by x-ray diffractometry, field emission scanning electron microscopy, and transmission electron microscopy. Structural investigations revealed the co-existence of mix-phased molybdenum oxide, i.e. dominant orthorhombic α-MoO3, and minor monoclinic Mo8O23 phases, within the modified PPS matrix. The resulting molybdenum oxide nanostructures had rod and sheet-like morphology in the PPS matrix. Dielectric measurements on pellets prepared from the resulting nanocomposites revealed improvement of the dielectric properties compared with values reported for pure PPS. The resulting nano-composites may exhibit properties synergistically derived from those of their components (molybdenum oxide and PPS), i.e. lower dielectric constant and loss tangent, enabling application as relatively high-temperature capacitors.