Inverse Vulcanization Research Articles

Sulfur-containing adsorbent made by inverse vulcanization of sulfur/oleylamine/potato starch for efficient removal of Hg(II) ions

Mercury contamination is considered the most harmful pollutant considering its high toxicity and persistence in the environment. This study aims to design an efficient and inexpensive adsorbent to capture Hg(II) ions. Herein, a polysulfide complex material was prepared through sulfur, oleylamine, and potato starch. Initially, the potato starch was functionalized by using dimethyl sulfoxide and (3-aminopropyl) triethoxysilane. The polysulfide adsorbent was then created by copolymerizing sulfur with oleylamine and sulfhydrylation starch using the inverse vulcanization process. The composition, structure, and morphology of polysulfide adsorbent were characterized by SEM/EDS, FT-IR, TGA, and XRD. The results indicated that the adsorption capacity and removal of adsorbent reached 248.2 mg/g and 99.28%. The adsorption data were fitted with adsorption kinetics, isothermal adsorption model and adsorption thermodynamics, followed by an analysis of the possible adsorption mechanism of the adsorbent. Meanwhile, it exhibited high selectivity for Hg(II) ions and other co-existing ions, with favorable recyclability after 5 rounds of recycling. In general, a promising polysulfide for the treatment of Hg(II)-containing wastewater is reported in this study, moreover, opening a novel avenue for elemental sulfur applications.

Sulfur Polymer as Emerging Advanced Materials: Synthesis and Applications

AbstractAbundant availability of inexpensive sulfur coupled with its reactivity triggered the interest of scientific community to explore the unique chemistry of sulfur for developing advanced materials. The reactivity of sulfur diradicals is used for making copolymers with cross‐linker monomer dienes through inverse vulcanization principle which is later upgraded by conducting reactions in presence of catalysts so as to achieve functionalized sulfur copolymers at lower reaction temperatures and lower time. Multi‐component reactions provide an opportunity for the direct utilization of sulfur at mild conditions. The diverse processing methodologies have further expanded the applicability of sulfur polymeric materials. The dynamicity of the S−S bonds has potential to create avenue for making self‐healing materials and usher the generation of more functionalized segmented block co‐polymers with superior properties. Interfacial condensation polymerization has successfully been implemented for the generation of sulfur nanoparticles in aqueous medium. The recent emergence of sulfur quantum dots through various approaches generated more advanced sulfur based materials in terms of expanding sulfur applications. This review provides an account on advanced materials synthesized using sulfur as raw material and their respective applications.

Near-infrared-light responsive degradable polysulfide pesticide carriers by one-pot inverse vulcanization

Functional carriers are appealing materials for pesticide formulations due to their superior role in improving pesticide utilization and reducing environmental pollution. Nevertheless, current carriers often involve tedious chemical synthesis and are time-consuming, which rise potential risks to environment and limit the large-scale industrialization. Here, taking advantage of inverse vulcanization reaction, a near-infrared responsive polysulfide carrier (SOCT) loading tebuconazole (Teb) is prepared in one-pot by using industrial waste sulfur (S8), bio-based soybean oil (SO), and agricultural waste biochar as raw materials. The facile solvent- and surfactant-free processing and the low-cost of raw materials make SOCT be produced easily in kilogram-scale with a loading content of 34.1 wt%. The resulting SOCT exhibits good photothermal property upon irradiation of NIR light, and its release behavior is stable enough against different pH values and coexisting ions, implementing the controlled release of Teb. In vitro and in vivo experiments indicate that SOCT has excellent fungicidal activities against three pathogenic fungi and high biosafety for wheat seed germination and adult zebrafish. In addition, the carrier material is able to be degraded completely in the presence of alkaline or dithiothreitol molecules, due to the available dynamic ester and S-S bonds in polysulfides. These unique features endow our carriers with promising potentials in practical agro-productions. To the best of our knowledge, this is the first time to use inverse vulcanization to prepare carrier materials for pesticides, which provides an effective approach for pesticide formulations with multi-functionality and sustainability.

A review on use of elemental sulphur in the synthesis of sulphur-based polymers

Sulfur is a plentiful and bioactive component that has been employed in a variety of industries. Despite being a plentiful and affordable chemical substrate, starting materials for chemical synthesis rarely utilise elemental sulphur. Nanoparticles have attracted the attention of researchers due to their widely differing physicochemical features from their bulk materials. Nanosulfur is produced via a nanotechnology process that takes use of structural parameters. Sulfur has been utilized in a variety of industries due to its abundance and biological activity. Through ring-opening polymerization, sulphur can be further converted into polymeric sulphur, which is utilised as a rubber vulcanizing agent.when inverse vulcanization is done for elemental sulphur with different monomeric unitswhich resulted into numerousiproperties. Chemical, structural, and kinetic analyses, as well as temperature,&mechanical basedapplications, used to adjust the characteristic of S-based polymers. Particularly, a number of sulphur composites were synthesized that performed satisfactorily. Here, we discuss some basic techniques for producing chemically inert and workable polymeric materials, and the processtermed as inverse vulcanization and processable polymeric materials. This method allowed sulphur to be converted into processable copolymer forms with controlled thermomechanical properties, resulting in well-defined sulphur-rich micro-patterned films produced by imprint lithography. Inverse vulcanization was employed to synthesise sulphur-based polymeric polymers from sulphur feedstock, elemental sulphur, and Botryococcene, sustainable alga oil. New ways for using elemental sulphur as a feedstock for innovative polymeric materials have recently been developed. In this review, we will look at how polymers could used as potential materials in Lithium-Sulphur cells. This structural and property study gives fundamental knowledge for future operation. Current advancements in the polymerization of elemental sulphur to produce polymers with high sulphur content are discussed in this paper.

A Microphase Separation Strategy for the Infrared Transparency‐Thermomechanical Property Conundrum in Sulfur‐Rich Copolymers (Advanced Optical Materials 5/2023)

In article number 2202432, Kyung Jin Lee, Jeong Jae Wie, Dong-Gyun Kim, and co-workers present an in-situ microphase separation strategy for the inverse vulcanization of elemental sulfur by utilizing self-crosslinkable 1,3,5-trivinylbenzene (TVB). Based on the microphase-separated architecture, poly(S-r-TVB)s exhibit robust thermomechanical properties, while still maintaining excellent infrared (IR) optical properties; such characteristics hold great promise for IR optical applications.

A semi-immobilized sulfur-rich copolymer backbone with conciliatory polymer skeleton and conductive substrates for high-performance Li-S batteries

Sulfur-rich polymers have gained a great deal of attention as the next-generation active materials in lithium-sulfur (Li-S) batteries due to their low cost, environmental compatibility, naturally sulfur uniform dispersion, and distinctive structure covalently bonding with sulfur atoms. However, the poor electrical conductivity and undesirable additional shuttle effect still hinder the commercial application of sulfur-rich polymers. Herein, we report a flexible semi-immobilization strategy to prepare allyl-terminated hyperbranched poly(ethyleneimine)-functionalized reduced graphene oxide (A-PEI-EGO) as sulfur-rich copolymer backbone. The semi-immobilization strategy can effectively reconcile the demand for polymer skeleton and conductive substrates through forming quaternary ammonium groups and reducing oxygen-containing functional groups, resulting in enhanced skeleton adsorption capacity and substrate electronic conductivity, respectively. Furthermore, the stable covalent bonding connection based on polymer molecules (A-PEI) not only completely prevents the additional shuttle effect of lithiation organic molecules and even sulfur-rich oligomers, but provides more inverse vulcanization active sites. As a result, the as-prepared A-PEI-EGO-S cathodes display an initial discharge capacity of 1338 mA h g−1 at a rate of 0.1 C and an outstanding cycling stability of 0.046% capacity decay per cycle over 600 cycles. Even under 6.2 mg cm−2 S-loaded and sparing electrolyte of 6 µL mg−1, the A-PEI-EGO-S cathode can also achieve a superior cycling performance of 98% capacity retention after 60 cycles, confirming its application potential.

Inverse Vulcanized Polymers for Sustainable Metal Remediation

AbstractHeavy metal exposure has an enormous burden on human health. Current metal removal technologies require substantial improvements in relation to their efficiency and environmental impact if this issue is to be addressed. Over the last decade, several new types of sulfur‐rich sorbents have been investigated. These polymers typically have high removal efficiencies for toxic metals such as mercury and are often made using sustainable and low‐cost reagents. This review surveys polymers made by inverse vulcanization that have been tested for metal capture. Focus is put on environmental impact, feedstock for sorbent synthesis, selectivity towards metal removal, toxicity studies, and the reusability of the polymers. Furthermore, this review discusses current limitations and the potential opportunities to use different comonomers for improved metal capture.

Reaction between 1,3,5-Triisopropylbenzene and Elemental Sulfur Extending the Scope of Reagents in Inverse Vulcanization.

Inverse vulcanization utilizes an organic compound as reagent for crosslinking elemental sulfur to result in corresponding polymeric material with a high sulfur content. This work, employing 1,3,5-triisopropylbenzene (TIPB) as the reagent, demonstrates the first attempt on extending the scope of crosslinking agents of inverse vulcanizationtosaturatecompounds. Under nuclearmagneticspectroscopic analysis, the reactions between TIPB and elemental sulfur take places through ring-opening reaction of S8 resulting in sulfur radicals at sulfur chain ends, radicals transferring to isopropyl groups of TIPB, and radical coupling reactions between carbon radicals and sulfur radicals. The obtained products are similar to the sulfur polymers from conventional inverse vulcanization processes and show self-healing property.

Influence of pozzolans on plant oil‐sulfur polymer cements: More sustainable and chemically‐resistant alternatives to Portland cement

AbstractLow cost and high durability have made Portland cement the most widely‐used building material, but benefits are offset by environmental harm of cement production contributing 8–10% of total anthropogenic CO2 gas emissions. High sulfur‐content materials (HSMs) are an alternative that can perform the binding roles as cements with a smaller carbon footprint, and possibly superior chemical, physical, and mechanical properties. Inverse vulcanization of 90 wt% sulfur with 10 wt% canola oil or sunflower oil to yield CanS or SunS, respectively. Notably, these HSMs prepared at temperatures ≤180 °C compared to >1200 °C hours for Portland cement CanS was combined with 5 wt% fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBFS), or metakaolin (MK) to give composites CanS‐FA, CanS‐SF, CanS‐GGBFS, and CanS‐MK, respectively. The analogous protocol with SunS likewise yielded SunS‐FA, SunS‐SF, SunS‐GGBFS, and SunS‐MK. Each of these HSMs exhibit high compressive mechanical strength, low water uptake values, and exceptional resistance to acid‐induced corrosion. All of the composites also exhibit superior compressive strength retention after exposure to acidic solutions, conditions under which Portland cement undergoes dissolution. The polymer cement‐pozzolan composites reported herein may thus serve as greener alternatives to traditional Portland cement in some applications.

Photo-Crosslinkable Inorganic/Organic Sulfur Polymers.

Inverse vulcanization techniques are used to fabricate thermodynamically stable, sulfur polymers. Sulfur-based polymers exhibit higher refractive indices and improved transparency in the mid-wave infrared region compared with most organic polymers. Herein, the postsynthetic modification of sulfur polymers created via inverse vulcanization to generate novel, inorganic/organic photoresists is discussed. Amine-containing sulfur resins are postfunctionalized with cross-linkable alkynes. The sulfur-based materials undergo rapid photo-crosslinking to generate patternable films within 10min under UV irradiation (365nm). The development of these resins enables sulfur polymers to be utilized in processes where spatial and hierarchical control is necessary. The generation of this class of materials also expands on sulfur-based organic polymer systems with optical applications.

A Microphase Separation Strategy for the Infrared Transparency‐Thermomechanical Property Conundrum in Sulfur‐Rich Copolymers

AbstractWith intrinsic optical and dynamic properties of polysulfide chains, inverse vulcanized copolymers have demonstrated immense potential for infrared (IR) optical applications. However, preparing highly IR‐transparent sulfur‐rich copolymers without sacrificing their thermomechanical properties remains challenging. To overcome the trade‐off relationship between IR optical and thermomechanical properties, an in situ microphase separation strategy for the inverse vulcanization of elemental sulfur utilizing self‐crosslinkable 1,3,5‐trivinylbenzene (TVB) is presented. Even with 80 wt% sulfur content, the microphase‐separated TVB‐rich domain self‐reinforces the copolymer with a noteworthy modulus of ≈2.0 GPa and a high glass transition temperature (Tg) of 92.6 °C, while still exhibiting outstanding IR optical properties. This work is expected to provide insights into the fundamental structure–property relationships of sulfur‐rich copolymers and pave the way for various practical applications.

Ultra-High-Capacity Lithium Metal Batteries Based on Multi-Electron Redox Reaction of Organopolysulfides including Conductive Organic Moieties

Recently, organic polysulfides have been synthesized as cathode active materials exceeding the battery performance of sulfur. However, the conventional organic polysulfides have exhibited capacities lower than the theoretical capacity of sulfur because the π-organic moieties do not conjugate with the sulfur chains. In this work, the organopolysulfides, synthesized via inverse vulcanization using disulfide compounds, exhibited higher capacities equal to the theoretical capacity of sulfur because of enhanced electronic conductivity based on the conjugation between organic moieties and sulfur chains. Furthermore, the organopolysulfide including 1,3-dhitiol-2-thione moiety exhibited the highest capacity because of the enhanced electronic conductivity. This finding will pave the way to develop next-generation rechargeable batteries.

Enhanced wastewater bioremediation by a sulfur-based copolymer as scaffold for microalgae immobilization (AlgaPol)

In recent years, there has been an increasing concern related to the contamination of aqueous ecosystems by heavy metals, highlighting the need to improve the current techniques for remediation. This work intends to address the problem of removing heavy metals from waterbodies by combining two complementary methodologies: adsorption to a copolymer synthesized by inverse vulcanization of sulfur and vegetable oils and phytoremediation by the microalga Chlorella sorokiniana to enhance the metal adsorption. After studying the tolerance and growth of Chlorella sorokiniana in the presence of the copolymer, the adsorption of highly concentrated Cd2+ (50 mg L−1) by the copolymer and microalgae on their own and the combined immobilized system (AlgaPol) was compared. Additionally, adsorption studies have been performed on mixtures of the heavy metals Cd2+ and Cu2+ at a concentration of 8 mg L−1 each. AlgaPol biofilm is able to remove these metals from the growth medium by more than 90%. The excellent metal adsorption capacity of this biofilm can be kinetically described by a pseudo-second-order model.

NEXAFS spectra of model sulfide chains: implications for sulfur networks obtained from inverse vulcanization.

Inverse vulcanization is a promising route to stabilize sulfur in lithium-sulfur batteries, but the resulting sulfur strand lengths in the materials are elusive. We address the strand length by characterization via sulfur near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Theoretical predictions of NEXAFS spectra for model molecules containing strands with up to three sulfur atoms are verified by experiment. The near perfect agreement between simulation and experiment on the absolute energy scale allows for the predictions for larger chain lengths also. Inspection and interpretation of NEXAFS spectra from real battery materials on this basis reveals the appearance of single connecting sulfur atoms for very low sulfur content, and of longer strands when the sulfur fraction increases.

Inverse vulcanisation of self-activating amine and alkyne crosslinkers

Self-activating crosslinkers were used to create inverse vulcanised polymers with improved properties via method optimised dispersion polymerisation, and were also used alongside other comonomers to enhance the product polymer's properties.

Synthesis and performance evaluation of slow-release fertilizers produced from inverse vulcanized copolymers obtained from industrial waste.

To improve crop nutrient uptake efficacy (NUE) and better manage fertilization, slow-release fertilizers (SRFs) are developed by either coating the urea granules or making a composite. Several materials have already been developed, nevertheless, scalability of those materials is still a challenge due to their inherit drawbacks (such as hydrophilicity, crystallinity, non-biodegradability, etc.). Herein, we utilized a biodegradable, green and sustainable copolymer produced from industrial waste (sulfur-petroleum industry waste and myrcene-citrus industry waste) to coat the urea using a facile coating method to develop novel SRFs and achieve better agronomic and environmental advantages. The copolymer was first synthesized using a facile, solvent-free one-pot method called inverse vulcanization followed by Fourier transform infrared spectroscopy (FTIR) analysis to confirm the successful reaction between myrcene and sulfur subsequently coating the copolymer on urea granule. The morphology and coating thickness of coated fertilizers were analysed using scanning electron microscopy (SEM), followed by a nitrogen release test in distilled water and a soil burial test to confirm the biodegradability. The nitrogen release test revealed that the SRF with the maximum coating thickness of 1733 μm releases only 16% of its total nitrogen after 4 days of incubation compared to the pristine urea which releases all its nutrient within 1 day. The soil burial test confirms the biodegradability of the copolymer, as after 50 days of incubation in soil the copolymer loses almost 18.25% of its total weight indicating that the copolymer is degrading.

Sulfur–oleylamine copolymer synthesizedviainverse vulcanization for the selective recovery of copper from lithium-ion battery E-waste

A novel sulfur–oleylamine copolymer as a promising sorbent to selectively recover Cu2+ions from a mixture of metal ions in acidic pH and its potential applications in battery recycling.

Inverse vulcanization of elemental sulfur catalyzed by trialkyl amines

Under eco-friendly trialkyl amine catalysis, facile and fast low-temperature inverse vulcanization of elemental sulfur using unreactive crosslinkers is enabled.

Comprehensive itaconic acid-based vitrimers via one-pot inverse vulcanization

Dual-dynamic itaconic acid-based vitrimers were constructed from industrial and agricultural byproducts by one-pot inverse vulcanization.

Interface Coupling in Rubber/Carbon Black Composites toward Superior Energy-Saving Capability Enabled by Amino-Functionalized Polysulfide

Natural rubber/carbon black (NR/CB) composites have found indispensable application in aircraft tires. Interfacial modification of NR/CB composites for acquiring uniform CB dispersion and strong interfacial adhesion is a persistent and challenging theme, as it is a prerequisite to improve comprehensive mechanical properties and decrease energy loss of the composites under dynamic deformations. In this work, we reported the use of an amino-functionalized polysulfide (PDAS) synthesized by inverse vulcanization of sulfur and m-phenylenediamine as a novel interfacial modifier in NR/CB composites. Specifically, the amino of PDAS can react with the carboxyl groups on the CB surface, meanwhile the polysulfide chains of PDAS can react with rubber chains, enabling the crosslinking of NR and establishment of a molecular bridge between NR and CB. The influences of PDAS dosages on CB dispersion and interfacial adhesion are revealed, and their correlations with composite properties are discussed. Compared with the unmodified counterpart, CB dispersion is greatly improved and interfacial adhesion is significantly enhanced in the PDAS-modified composite having an identical crosslink density, leading to remarkably decreased hysteresis loss. In addition, PDAS can significantly resist thermal-oxidative aging of the composites due to its radical scavenging activity.