Sulfidation Behavior Research Articles

Experimental study of hydrogen sulfide (H2S) behavior in brine/n-decane mixtures under HPHT conditions

This research investigates the dynamic behavior of hydrogen sulfide (H2S) under oil reservoir conditions, focusing on their interplay within both aqueous and organic phases. Surprising findings emerge, notably the heightened solubility of H2S at 250°C compared to 150°C, with values of 19.9 mg to 41.5 and 12.8 mg to 16.4 mg in 100ml of solution, respectively, diverging from conventional expectations, due to organosulfur compounds generated at the water/n-decane interface under high pressure and temperature conditions. Through an examination of Henry's Law and the calculation of Henry's constants across several temperatures, insights into these observations are gained. In the organic phase, temperature is observed to catalyze the formation of organosulfur compounds from n-decane and H2S. Notable compounds identified include aromatic hydrocarbons bearing sulfur substituents. highlighting the presence of 2-Propyldibenzothiophene (2 – 392 mg/mL), which represents between 57 and 95% of the total concentration of organosulfur compounds found in the organic fraction, being more abundant at 250°C. These findings underscore the intricate interplay between temperature, pressure, and phase composition, elucidating the nuanced solubility patterns and reaction dynamics of sulfur and organosulfur compounds.

Sulfidation of Smithsonite via Microwave Roasting under Low-Temperature Conditions

This study employs microwave roasting to decompose smithsonite mineral (zinc carbonate) into zinc oxide, which then reacts with pyrite to sulfurize its surface, forming zinc sulfide. This process is beneficial for the flotation recovery of zinc oxide minerals. The surface sulfidation behavior of smithsonite under low-temperature microwave roasting conditions is examined through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermodynamic calculations. XRD and thermodynamic analysis indicate that smithsonite completely decomposes into zinc oxide at 400 °C. Introducing a small amount of pyrite as a sulfidizing reagent leads to the formation of sulfides on the surface of decomposed smithsonite. XPS analysis confirms that the sulfide formed on the surface is zinc sulfide. SEM analysis reveals that sulfides are distributed on the surface of smithsonite, and the average sulfur concentration increases with the pyrite dosage. Microwave-assisted sulfurization of smithsonite (ZnCO3) was found to significantly enhance its floatability compared to conventional sulfurization methods. The optimal mass ratio of ZnCO3 to FeS2 is approximately 1:1.5, with the best temperature being 400 °C. These findings provide a technical solution for the application of microwave roasting in the efficient recovery of smithsonite through flotation.

Study on the effect of Al-La composite deoxidation on the modification behaviors of TiN and sulfide inclusions in 20CrMnTi gear steel

This article uses experimental and thermodynamic calculations to study the directional modification behavior of TiN and sulfides in 20CrMnTi steel before and after the addition of rare earth La element. The morphologies (SEM) and elemental distributions (EDS) of TiN and sulfide inclusions in steel are characterized using scanning electron microscopy, and the sizes of the inclusions are statistically analyzed. With the addition of rare earth La, the average sizes of TiN and sulfide inclusions in steel decrease, and the proportions of TiN and sulfide inclusions in all inclusions of the steel decrease. The results show that the addition of La element can promote the formation of LaAlO3 in steel, which can be used as the nucleation core of TiN and MnS inclusions in steel, and then form LaAlO3-TiN and LaAlO3-MnS-TiN composite inclusions, which are smaller in size and more uniform in distribution than TiN and sulfide in steel before La element is added. When La is added alone, the average size of TiN inclusion in steel is 2.2 μm. After the deoxidation of Al-La alloy, the average size of TiN inclusion in the steel is 1.9 μm. After Al-La composite deoxidation, the TiN containing inclusions in the steel will be transformed into smaller LaAlO3-TiN composite inclusions. When adding La alone, the average size of sulfide inclusions in the steel is 2.1 μm. When Al-La composite deoxygenation is used, the average size of sulfide inclusions in steel is 1.1 μm, indicating that the Al-La composite deoxygenation has a better improvement effect on sulfide inclusions in steel than the improvement effect of adding La alone.

Enhanced catalytic performance of M-doped SnS2 (M: Ni, Cu, Fe, and Co) and graphene nanocomposite for oxygen reduction reaction in alkaline media

In this study, the electrocatalytic behavior of tin sulfide doped with various metallic elements (copper, cobalt, nickel, and iron) for the oxygen reduction reaction was investigated. Our findings reveal cobalt as the most effective dopant in enhancing ORR efficiency. The graphene nanosheets were introduced to form a G/Co-SnS2 nanocomposite, which significantly improved ORR performance, surpassing Pt/C in current density. Our findings underscore the positive impact of chemical doping and the synergistic effect of SnS2 with graphene nanosheets, improving the onset potential and facilitating the ORR. Through comprehensive characterization including XRD, XPS, FESEM, and BET analysis, the structural and surface properties of the materials were evaluated. Employing the Rotating Disk Electrode technique, we observed that G/Co-SnS2 exhibited a superior onset potential of 0.88 V vs. RHE and high current density of 6.12 mA cm−2, indicating enhanced ORR facilitation. Furthermore, Electrochemical Impedance Spectroscopy revealed lower resistance in the G/Co-SnS2 nanocomposite compared to other samples, highlighting its enhanced durability. Additionally, G/Co-SnS2 nanocomposite demonstrated significantly enhanced durability in comparison to the costly Pt/C catalyst, further underscoring its potential as a robust alternative for catalyzing the oxygen reduction reaction. These comprehensive characterizations provide insights into the enhanced electrocatalytic performance observed. Overall, this study highlights the promising potential of Co-doped SnS2 in combination with graphene nanosheets for efficient oxygen reduction reactions, opening avenues for advanced electrocatalytic materials in energy applications.

Measuring Mass Transfer of n-Hexane and 2-Chloroethyl Ethyl Sulfide in Sorbent/Polymer Fiber Composites Using a Volumetric Adsorption Apparatus.

The integration of metal-organic frameworks (MOFs) into composite systems serves as an effective strategy to increase the processability of these materials. Notably, MOF/fiber composites have shown much promise as protective equipment for the capture and remediation of chemical warfare agents. However, the practical application of these composites requires an understanding of their mass transport properties, as both mass transfer resistance at the surface and diffusion within the materials can impact the efficacy of these materials. In this work, we synthesized composite fibers of MOF-808 and amidoxime-functionalized polymers of intrinsic microporosity (PIM-1-AX) and measured the adsorption and mass transport behavior of n-hexane and 2-chloroethyl ethyl sulfide (CEES), a sulfur mustard simulant. We developed a new Fickian diffusion model for cylindrical shapes to fit the dynamic adsorption data obtained from a commercial volumetric adsorption apparatus and found that mass transport behavior in composite fibers closely resembled that in the pure PIM fibers, regardless of MOF loading. Moreover, we found that n-hexane adsorption mirrors that of CEES, indicating that it could be used as a structural mimic for future adsorption studies of the sulfur mustard simulant. These preliminary insights and the new model introduced in this work lay the groundwork for the design of next-generation composite materials for practical applications.

LATTICE DYNAMICAL STUDY OF THORIUM SULPHIDE

Thorium sulfide (ThS) is a chemical compound composed of thorium and sulfur atoms, with the chemical formula ThS. It belongs to the class of sulfides. To understand the dimensional stability and thermal behaviour of thorium sulphide (ThS), a lattice dynamical research issued to investigate its vibrational characteristics. We study the density of states (DOS) and phonon dispersion in the 50–60 GHz frequency region using computational techniques. Important information about the stability of the ThS crystal structure are given by the phonon dispersion curves, namely the presence of imaginary phonon frequencies that point to dynamical stability. We identify the major modes of vibration and their contributions to the thermodynamic properties of ThS through studying the phonon density of states.Van der Waals' three-body force shell model is used in this study to theoretically investigate the lattice dynamical behaviour of (ThS...). Elastic constants, pressure derivatives, dispersion relation curve, combined density of states, equation of state, and specific ultrasonic properties of the ThS are among the parameters for which calculated values are gave.The stability of the structure and vibrational properties of thorium sulphide are now better known by lattice dynamical study, which provides the way to its effective application in a range of technological uses, from nuclear reactors to the production of creative materials. Keywords: lattice, dynamics, thermal, vibrational

Formation of 2D Amorphous Lithium Sulfide Enabled by Mo2C Clusters Loaded Carbon Scaffold for High-Performance Lithium Sulfur Batteries.

Lithium-sulfur (Li-S) batteries, operated through the interconversion between sulfur and solid-state lithium sulfide, are regarded as next-generation energy storage systems. However, the sluggish kinetics of lithium sulfide deposition/dissolution, caused by its insoluble and insulated nature, hampers the practical use of Li-S batteries. Herein, leaf-like carbon scaffold (LCS) with the modification of Mo2C clusters (Mo2C@LCS) is reported as host material of sulfur powder. During cycles, the dissociative Mo ions at the Mo2C@LCS/electrolyte interface are detected to exhibit competitive binding energy with Li ions for lithium sulfide anions, which disrupts the deposition behavior of crystalline lithium sulfide and trends a shift in the configuration of lithium sulfide toward an amorphous structure. Combining the related electrochemical study and first-principle calculation, it is revealed that the formation of amorphous lithium sulfides shows significantly improved kinetics for lithium sulfide deposition and decomposition. As a result, the obtained Mo2C@LCS/S cathode shows an ultralow capacity decay rate of 0.015% per cycle at a high mass loading of 9.5mg cm-2 after 700 cycles. More strikingly, an ultrahigh sulfur loading of 61.2mg cm-2 can also be achieved. This work defines an efficacious strategy to advance the commercialization of Mo2C@LCS host for Li-S batteries.

Revealing cellular (poly)sulphide storage in electrochemically active sulphide oxidising bacteria using rotating disc electrodes

Sulphide oxidising bacteria (SOB) have the potential to be used for bioelectrochemical removal, i.e. oxidation, of sulphide from waste streams. In anaerobic conditions, SOB are able to spatially separate sulphide removal and terminal electron transfer to an electrode and act as a sulphide shuttle. However, it is not fully understood how SOB anaerobically remove sulphide and store charge equivalents, and where in this process sulphur is formed. Therefore, the redox behaviour of sulphide shuttling SOB was investigated at haloalkaline conditions using a glassy carbon rotating disc electrode (RDE) and cyclic voltammetry. Voltammograms of SOB in the absence and presence of sulphide were compared to voltammograms of abiotic sulphur species solutions. Polysulphide and sulphide showed different redox behaviour, with distinct potentials for oxidation of > −0.3 V (vs. Ag/AgCl) for polysulphide and > −0.1 V for sulphide. Comparing biotic to abiotic experiments lead to the hypothesis that SOB formed polysulphides during anaerobic sulphide removal, which stayed sorbed to the cells. With this study, further steps were taken in elucidating the mechanisms of sulphide shuttling by SOB.

Adsorption behavior of hydrogen sulfide in the channels of Li-ABW zeolite: A study using density functional theory

H2S is a highly toxic, flammable gas that poses risks to health, the environment, and industrial infrastructure. Zeolites, with their high porosity, offer a promising solution for its removal. This study employs density functional theory (DFT) to investigate the adsorption behavior of H2S within the Li-ABW zeolite framework, focusing on the synergistic effect of co-adsorbed water molecules. Six distinct systems were modeled: empty Li-ABW zeolite, half and full filled Li-ABW with H2O or H2S molecules, and equally filled zeolite with H2S and H2O molecules. Detailed analysis of geometric, energetic, and electronic properties reveals that the presence of water significantly enhances H2S adsorption in Li-ABW. Increased bond lengths between H2S and the zeolite framework suggest possible dissociative adsorption, while weakened H2S-zeolite interaction compared to H2O-zeolite interaction indicates facile H2S desorption. Furthermore, charge transfer analysis and HOMO/LUMO plots highlight stronger interactions and a more balanced electron distribution in the co-adsorbed system. Interestingly, the presence of water minimizes structural deformations of the zeolite framework while facilitating the formation of additional hydrogen bonds, potentially further promoting H2S desorption through water extraction. These findings demonstrate that Li-ABW zeolite, particularly in conjunction with water molecules, exhibits remarkable potential for efficient and selective H2S adsorption, offering promising avenues for practical applications in gas sweetening and industrial gas purification. In order to realize this potential, further investigation into the effects of solvents and cation exchange is necessary, which are outlined for future research.

Insights into sulfur and hydrogen sulfide induced corrosion of sintered nanocopper paste: A combined experimental and ab initio study

The power semiconductor joining technology through sintering of copper nanoparticles is well-suited for die attachment in wide bandgap (WBG) semiconductors, offering high electrical, thermal, and mechanical performances. However, sintered nanocopper will be prone to degradation resulting from corrosion in sulfur-containing corrosive environments such as offshore areas. In this study, experiments, including aging test and corrosion characterization, and simulations based on density functional theory (DFT) studies were conducted to explore the corrosion behavior and mechanism of elemental sulfur (S8) and hydrogen sulfide (H2S) on sintered nanocopper. The experimental results indicated that loose corrosion products were observed on the sintered nanocopper during the ageing process involving S8, and compact layered corrosion products formed during the ageing process involving H2S. Furthermore, similar corrosion product compositions (Cu2O, Cu2S, CuO, CuS, and potentially Cu2SO4 or CuSO4) were observed in both the S8- and H2S-ageing processes. However, the S8-ageing process exhibited more noticeable corrosion penetration. This was explained in simulations results: the unsaturated Cu sites on the oxide layer [Cu2O(111)] of the sintered nanocopper could adsorb both H2S and S8, while the saturated Cu sites only exhibited the potential to adsorb S8.

Sulfidation behavior of an AlCoCrNiSi high‐entropy alloy

AbstractHigh‐entropy alloys (HEAs) are promising new materials considered for application in high temperature environments. In this work, the sulfidation behavior of an Al–Co–Cr–Ni–Si HEA at different elevated temperatures and various sulfur vapor partial pressures is investigated. Thermogravimetric studies indicate that the sulfidation kinetics are in accordance with the parabolic rate law. The corrosion rate has a strong temperature dependence, whereas the influence of sulfur vapor pressure is practically nonexistent. Changes in temperature also do not seem to affect the sulfidation mechanism as evidenced by the Arrhenius correlation determined between the obtained parabolic rate constants and temperature. Combined SEM–EDS and XRD studies reveal the formation of a thick multilayer scale on the studied alloy, where the outermost relatively compact part is built of Co0.5NiS2 and CrAl2S4 while the inner, rather porous part also contains metallic inclusions, including Si near the scale/substrate interface.

Behavior of bismuth and manganese sulfide in free-cutting steel

Behavior of bismuth and manganese sulfide in free-cutting steel

The Influence of Thermal Parameters on the Self-Nucleation Behavior of Polyphenylene Sulfide (PPS) during Secondary Thermoforming.

During the secondary thermoforming of carbon fiber-reinforced polyphenylene sulfide (CF/PPS) composites, a vital material for the aerospace field, varied thermal parameters profoundly influence the crystallization behavior of the PPS matrix. Notably, PPS exhibits a distinctive self-nucleation (SN) behavior during repeated thermal cycles. This behavior not only affects its crystallization but also impacts the processing and mechanical properties of PPS and CF/PPS composites. In this article, the effects of various parameters on the SN and non-isothermal crystallization behavior of PPS during two thermal cycles were systematically investigated by differential scanning calorimetry. It was found that the SN behavior was not affected by the cooling rate in the second thermal cycle. Furthermore, the lamellar annealing resulting from the heating process in both thermal cycles affected the temperature range for forming the special SN domain, because of the refined lamellar structure, and expelled various defects. Finally, this study indicated that to control the strong melt memory effect in the first thermal cycle, both the heating rate and processing melt temperature need to be controlled simultaneously. This work reveals that through collaborative control of these parameters, the crystalline morphology, crystallization temperature and crystallization rate in two thermal cycles are controlled. Furthermore, it presents a new perspective for controlling the crystallization behavior of the thermoplastic composite matrix during the secondary thermoforming process.

The sulfidation behavior of zinc during microwave hydrothermal sulfidation of heavy metal-containing sludge

ABSTRACT The heavy metals present in the sludge can undergo a reaction with sulfur, leading to their conversion into metal sulfides through hydrothermal sulfidation. Sulfur ions, possessing a strong sulfidation capability, can operate within a wider pH range at elevated temperatures. The high temperature environment promotes the sulfidation process of zinc within heavy metal-laden sludge. Increasing the temperature of microwave hydrothermal sulfidation and extending the sulfidation duration for heavy metal-containing sludge can enhance the growth of crystal size in the artificially synthesized zinc sulfide. Zinc sulfide predominantly takes the form of ZnS, which facilitates the subsequent flotation recovery of zinc.

Surface Structure to Tailor the Electrochemical Behavior of Mixed-Valence Copper Sulfides during Water Electrolysis.

The semiconducting behavior of mixed-valence copper sulfides arises from the pronounced covalency of Cu-S bonds and the exchange coupling between CuI and CuII centers. Although electrocatalytic study with digenite Cu9S5 and covellite CuS has been performed earlier, detailed redox chemistry and its interpretation through lattice structure analysis have never been realized. Herein, nanostructured Cu9S5 and CuS are prepared and used as electrode materials to study their electrochemistry. Powder X-ray diffraction (PXRD) and microscopic studies have found the exposed surface of Cu9S5 to be d(0015) and d(002) for CuS. Tetrahedral (Td) CuII, distorted octahedral (Oh) CuII, and trigonal planar (Tp) CuI sites form the d(0015) surface of Cu9S5, while the (002) surface of CuS consists of only Td CuII. The distribution of CuI and CuII sites in the lattice, predicted by PXRD, can further be validated through core-level Cu 2p X-ray photoelectron spectroscopy (XPS). The difference in the electrochemical response of Cu9S5 and CuS arises predominantly from the different copper sites present in the exposed surfaces and their redox states. In situ Raman spectra recorded during cyclic voltammetric study indicates that Cu9S5 is more electrochemically labile compared to CuS and transforms rapidly to CuO/Cu2O. Contact-angle and BET analyses imply that a high-surface-energy and macroporous Cu9S5 surface favors the electrolyte diffusion, which leads to a pronounced redox response. Post-chronoamperometric (CA) characterizations identify the potential-dependent structural transformation of Cu9S5 and CuS to CuO/Cu2O/Cu(OH)2 electroactive species. The performance of the in situ formed copper-oxides towards electrocatalytic water-splitting is superior compared to the pristine copper sulfides. In this study, the redox chemistry of the Cu9S5/CuS has been correlated to the atomic arrangements and coordination geometry of the surface exposed sites. The structure-activity correlation provides in-depth knowledge of how to interpret the electrochemistry of metal sulfides and their in situ potential-driven surface/bulk transformation pathway to evolve the active phase.

Acid and ammonia leaching of secondary copper sulfides

The study focuses on understanding the efficiency and kinetics of copper recovery from secondary sulphide ores, which are increasingly becoming a significant source of copper. An experimental investigation was undertaken to assess the leaching behaviour of secondary copper sulphides in acid and ammonia media. The test work consisted of ore sample characterisation, including physico-mechanical properties determination, chemical assay, whole rock analysis, mineralogy, and copper distributions, followed by acid consumption tests, agglomeration, and agitation leach tests. Leaching tests were conducted in a lab-scale agitated reactor using 100 g of the ore sample, 0.3 l of leach solution, а stirring rate of 420 rpm and a leach time of up to 200 hours. The effect of the reaction time and oxidant (Fe3+, NO+) concentration on the copper recovery was evaluated. The maximum copper extraction was obtained in the test performed using acid media with the addition of NO+ as an oxidant. Further, a potential hydrometallurgical process option for recovering copper from secondary sulphide sources is proposed.

Using TOXCHEM model for simulation the hydrogen sulfide behavior in a full-scale MBBR process

Odors emanating from treatment plants are a source of concern for those working in these plants. Hydrogen sulfide gas is the most dangerous aromatic compound for WWTP workers and plant equipment and facilities. In this study, hydrogen sulfide gas was modeled using the TOXCHEM model of the Aoun sewage treatment plant, which operates with the MBBR system. The TOXCHEM model was calibrated and validated and the results were within the R and RMSE parameters. Sensitivity analysis was studied on the most important factors affecting the emission of hydrogen sulfide gas in the Aoun sewage treatment plant. The results showed that the most important processes that obtain hydrogen sulfide gas are biodegradation, absorption, emission or volatilization. The results in winter, (12 °C), and summer (35 °C) about 6% and 8%, 18% and 17%, 72% and 65%, 0% and 0%, and 4% and 10% were fated as emitted to air, sorbed to sludge, discharged with effluent, biodegraded, and treated with odor removal system, respectively. The highest emission of hydrogen sulfide gas was observed in the preliminary stage (lift station, course and fine screen, API, and equalization tank), especially in the API basin, where it reached 1.8 ppm. Increasing temperatures, the air flow rate, decreasing the value of pH, increasing the flow and increasing the filling time in the pumping station all cause an increase in the emission of hydrogen sulfide gas. Modeling hydrogen sulfide gas by TOXCHEM model gave an excellent prediction to control the emission of hydrogen sulfide gas for decision makers in the plant.

Mid‐Infrared Spectroscopy of Sulfidation Reaction Products and Implications for Sulfur on Mercury

AbstractWe propose that the observed enrichment of sulfur at the surface of Mercury (up to 4 wt.%) is the product of silicate sulfidation reactions with a S‐rich reduced volcanogenic gas phase. Here, we present new experiments on the sulfidation behavior of olivine, diopside, and anorthite. We investigate these reaction products, and those of sulfidized glasses with Mercury compositions previously reported, by mid‐IR reflectance spectroscopy. We investigate both the reacted bulk materials as powders as well as cross‐sections of the reaction products by in situ micro‐IR spectroscopy. The mid‐IR spectra confirm the presence of predicted reaction products including quartz. The mid‐IR reflectance of sulfide reaction products, such as CaS (oldhamite) or MgS (niningerite), is insufficient to be observed in the complex run products. However, the ESA/JAXA BepiColombo mission to Mercury will be able to test our hypothesis by investigating the correlated abundances of sulfides with other reaction products such as quartz.

Control of the Composition and Morphology of Non-Metallic Inclusions in Superduplex Stainless Steel

Duplex stainless steel is a unique material for cast products, the use of which is possible in various fields. With the same chemical composition, melting, casting and heat treatment technology, pitting and crevice corrosion were observed at the interphase boundaries of non-metallic inclusions and the steel matrix. To increase the cleanliness of steel, it is necessary to carefully select the technology for deoxidizing with titanium or aluminum, as the most common deoxidizers, and the technology for modifying with rare earth metals. In this work, a comprehensive analysis of the thermodynamic data in the literature on the behavior of oxides and sulfides in this highly alloyed system under consideration was performed. Based on this analysis, a thermodynamic model was developed to describe their behavior in liquid and solidified duplex stainless steels. The critical concentrations at which the existence of certain phases is possible during the deoxidation of DSS with titanium, aluminum and modification by rare earth metals, including the simultaneous contribution of lanthanum and cerium, was determined. Experimental ingots were produced, the cleanliness of experimental steels was assessed, and the key metric parameters of non-metallic inclusions were described. In steels deoxidized using titanium, clusters of inclusions with a diameter of 84 microns with a volume fraction of 0.066% were formed, the volume fraction of which was decreased to 0.01% with the subsequent addition of aluminum. The clusters completely disappeared when REMs were added. The reason for this behavior of inclusions was interpreted using thermodynamic modeling and explained by the difference in temperature at which specific types of NMIs begin to form. A comparison of experimental and calculated results showed that the proposed model adequately describes the process of formation of non-metallic inclusions in the steel under consideration and can be used for the development of industrial technology.

Polyphenylene sulfide for high-rate composite manufacturing: Impacts of processing parameters on chain architecture, rheology, and crystallinity

High performance semi-crystalline thermoplastics necessitate high temperature processing to form useful structures, but the effects of repeated exposure to these extreme environments on key polymer properties are not well understood. This work investigates the influence of degradation-driven structural changes resulting from exposure to standard melt processing conditions in oxygen rich environments on the rheological properties, crystallization behavior, and crystal structure of polyphenylene sulfide (PPS). Melt processing temperatures (300°C, 320°C, and 340°C) and hold times (up to 60 min) are varied to probe the effects of thermal exposure on polymer properties. Extended melt-state exposure causes an increase in PPS melt viscosity due to the formation of complex branched/crosslinked structures where increasing temperature causes this process to occur more rapidly. Dynamic isothermal rheology of PPS displays a 70x increase in the complex viscosity at 10 rad/s after 60 minutes at 340°C. Frequency sweep rheological experiments reveal a notable deviation from linearity (terminal slope = 2) with slopes as low as 0.14 after thermal exposure. Stress recovery experiments indicate thermally processed PPS requires more time to relax stress under an applied strain. Imperfections along the polymer backbone in the form of branches/crosslinks decrease overall crystallinity and reduce lamellar thickness, with no changes to the unit cell structure. For semi-crystalline high performance thermoplastic matrix composites relying on high degrees of crystallinity to provide solvent resistance and strength, these results have serious implications for the need to tightly control melt processing steps and understand the final material state. Furthermore, viscoelastic properties of post-processed PPS polymers should be considered for recycling and reuse strategies.