Browse
Submit Data
Databases
API
Help

Dataset Information

20 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Catalytic inverse vulcanization.

ABSTRACT: The discovery of inverse vulcanization has allowed stable polymers to be made from elemental sulfur, an unwanted by-product of the petrochemicals industry. However, further development of both the chemistry and applications is handicapped by the restricted choice of cross-linkers and the elevated temperatures required for polymerisation. Here we report the catalysis of inverse vulcanization reactions. This catalytic method is effective for a wide range of crosslinkers reduces the required reaction temperature and reaction time, prevents harmful H₂S production, increases yield, improves properties, and allows crosslinkers that would be otherwise unreactive to be used. Thus, inverse vulcanization becomes more widely applicable, efficient, eco-friendly and productive than the previous routes, not only broadening the fundamental chemistry itself, but also opening the door for the industrialization and broad application of these fascinating materials.

SUBMITTER: Wu X

PROVIDER: S-EPMC6367372 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Catalytic inverse vulcanization.

Wu Xiaofeng X Smith Jessica A JA Petcher Samuel S Zhang Bowen B Parker Douglas J DJ Griffin John M JM Hasell Tom T

Nature communications 20190207 1

The discovery of inverse vulcanization has allowed stable polymers to be made from elemental sulfur, an unwanted by-product of the petrochemicals industry. However, further development of both the chemistry and applications is handicapped by the restricted choice of cross-linkers and the elevated temperatures required for polymerisation. Here we report the catalysis of inverse vulcanization reactions. This catalytic method is effective for a wide range of crosslinkers reduces the required reacti ...[more]

PMID: 30733431

Similar Datasets

Inverse Vulcanization of Styrylethyltrimethoxysilane - Coated Surfaces, Particles and Crosslinked Materials.

Project description:Sulfur as a side product of natural gas and oil refining is an underused resource. Converting landfilled sulfur waste into materials merges the ecological imperative of resource efficiency with economic considerations. A strategy to convert sulfur into polymeric materials is the inverse vulcanization reaction of sulfur with alkenes. However, the formed materials are of limited applicability, since they need to be cured at high temperatures (> 130 °C) for multiple hours. Herein, the reaction of elemental sulfur with styrylethyltrimethoxysilane is reported. Marrying the inverse vulcanization and silane chemistry yielded high sulfur content polysilanes, which could be cured via room temperature polycondensation to obtain coated surfaces, particles, and crosslinked materials. The polycondensation was triggered by hydrolysis of poly(sulfur-r-styrylethyltrimethoxysilane) (poly(Sn-r- StyTMS) under mild conditions (HCl, pH 4). For the first time, an inverse vulcanization polymer could be conveniently coated and mildly cured via post-polycondensation. Silica microparticles coated with the high sulfur content polymer could improve their Hg2+ ion remediation capability.

| S-EPMC7589442 | biostudies-literature

Chemically induced repair, adhesion, and recycling of polymers made by inverse vulcanization.

Project description:Inverse vulcanization is a copolymerization of elemental sulfur and alkenes that provides unique materials with high sulfur content (typically ?50% sulfur by mass). These polymers contain a dynamic and reactive polysulfide network that creates many opportunities for processing, assembly, and repair that are not possible with traditional plastics, rubbers and thermosets. In this study, we demonstrate that two surfaces of these sulfur polymers can be chemically joined at room temperature through a phosphine or amine-catalyzed exchange of the S-S bonds in the polymer. When the nucleophile is pyridine or triethylamine, we show that S-S metathesis only occurs at room temperature for a sulfur rank > 2-an important discovery for the design of polymers made by inverse vulcanization. This mechanistic understanding of the S-S metathesis was further supported with small molecule crossover experiments in addition to computational studies. Applications of this chemistry in latent adhesives, additive manufacturing, polymer repair, and recycling are also presented.

| S-EPMC7441575 | biostudies-literature

Scalable High Refractive Index polystyrene-sulfur nanocomposites via in situ inverse vulcanization.

Project description:In this work, we demostrate the preparation of low cost High Refractive Index polystyrene-sulfur nanocomposites in one step by combining inverse vulcanization and melt extrusion method. Poly(sulfur-1,3-diisopropenylbenzene) (PS-SD) copolymer nanoparticles (5 to 10 wt%) were generated in the polystyrene matrix via in situ inverse vulcanization reaction during extrusion process. Formation of SD copolymer was confirmed by FTIR and Raman spectroscopy. SEM and TEM further confirms the presence of homogeneously dispersed SD nanoparticles in the size range of 5 nm. Thermal and mechanical properties of these nanocomposites are comparable with the pristine polystyrene. The transparent nanocomposites exhibits High Refractive Index n = 1.673 at 402.9 nm and Abbe'y number ~ 30 at 10 wt% of sulfur loading. The nanocomposites can be easily processed into mold, films and thin films by melt processing as well as solution casting techniques. Moreover, this one step preparation method is scalable and can be extend to the other polymers.

| S-EPMC7483506 | biostudies-literature

High sulfur content polymers: The effect of crosslinker structure on inverse vulcanization.

Project description:The discovery of inverse vulcanization has allowed polymers to be made using elemental sulfur as the major component. However, until now, there has been little discussion of why seemingly similar crosslinkers result in polymers with radically different properties. Combining synthesis, spectroscopy, and modeling, this study reveals the structure-property relationships of sulfur polymers and reports a new system using 5-ethylidene-2-norbornene as a crosslinker that can stabilize up to 90 wt % of elemental sulfur.

| S-EPMC6175008 | biostudies-literature

Inverse Vulcanization of Norbornenylsilanes: Soluble Polymers with Controllable Molecular Properties via Siloxane Bonds.

Project description:The inverse vulcanization produces high sulfur content polymers from alkenes and elemental sulfur. Control over properties such as the molar mass or the solubility of polymers is not well established, and existing strategies lack predictability or require large variations of the composition. Systematic design principles are sought to allow for a targeted design of materials. Herein, we report on the inverse vulcanization of norbornenylsilanes (NBS), with a different number of hydrolysable groups at the silicon atom. Inverse vulcanization of mixtures of NBS followed by polycondensation yielded soluble high sulfur content copolymers (50 wt % S) with controllable weight average molar mass (MW ), polydispersity (Đ), glass transition temperature (TG ), or zero-shear viscosity (η0 ). Polycondensation was conducted in the melt with HCl as a catalyst, abolishing the need for a solvent. Purification by precipitation afforded polymers with a greatly reduced amount of low molar mass species.

| S-EPMC9302686 | biostudies-literature

High strength, epoxy cross-linked high sulfur content polymers from one-step reactive compatibilization inverse vulcanization.

Project description:Inverse vulcanization provides a simple, solvent-free method for the preparation of high sulfur content polymers using elemental sulfur, a byproduct of refining processes, as feedstock. Despite the successful demonstration of sulfur polymers from inverse vulcanization in optical, electrochemical, and self-healing applications, the mechanical properties of these materials have remained limited. We herein report a one-step inverse vulcanization using allyl glycidyl ether, a heterobifunctional comonomer. The copolymerization, which proceeds via reactive compatibilization, gives an epoxy cross-linked sulfur polymer in a single step, as demonstrated through isothermal kinetic experiments and solid-state 13C NMR spectroscopy. The resulting high sulfur content (≥50 wt%) polymers exhibited tensile strength at break in the range of 10-60 MPa (70-50 wt% sulfur), which represents an unprecedentedly high strength for high sulfur content polymers from vulcanization. The resulting high sulfur content copolymer also exhibited extraordinary shape memory behavior along with shape reprogrammability attributed to facile polysulfide bond rearrangement.

| S-EPMC8729804 | biostudies-literature

Inverse Vulcanization of a Natural Monoene with Sulfur as Sustainable Electrochemically Active Materials for Lithium-Sulfur Batteries.

Project description:A novel soluble copolymer poly(S-MVT) was synthesized using a relatively quick one-pot solvent-free method, inverse vulcanization. Both of the two raw materials are sustainable, i.e., elemental sulfur is a by-product of the petroleum industry and 4-Methyl-5-vinylthiazole (MVT) is a natural monoene compound. The microstructure of poly(S-MVT) was characterized by FT-IR, 1H NMR, XPS spectroscopy, XRD, DSC SEM, and TEM. Test results indicated that the copolymers possess protonated thiazole nitrogen atoms, meso/macroporous structure, and solubility in tetrahydrofuran and chloroform. Moreover, the improved electronic properties of poly(S-MVT) relative to elemental sulfur have also been investigated by density functional theory (DFT) calculations. The copolymers are utilized successfully as the cathode active material in Li-S batteries. Upon employment, the copolymer with 15% MVT content provided good cycling stability at a capacity of ∼514 mA h g-1 (based on the mass of copolymer) and high Coulombic efficiencies (∼100%) over 100 cycles, as well as great rate performance.

| S-EPMC8618051 | biostudies-literature

Catalytic effect of high thermal conductive SiC on the kinetics and thermodynamics of vulcanization reaction of SBR/BR-filled nano-SiC.

Project description:Nano-silicon carbide (SiC) as a high thermal conductive material with an intrinsic thermal conductivity of ~ 490 W/m K was used to improve the cure characteristics, kinetics, and thermodynamics of curing reaction of styrene-butadiene rubber/butadiene rubber (SBR/BR) compounds. The considerations were carried out by non-isothermal differential scanning calorimetry (DSC). Results revealed that the presence of SiC shifted the peak and end temperatures of the curing peak to lower temperatures. The calculated activation energy of the curing reaction based on the Kissinger approach showed a descent from 409.8 to 93.8 kJ/mol by adding SiC from 0 to 7.5 phr (part per hundred rubber). Moreover, the obtained Gibbs free energy variation and equilibrium constant of the curing reaction proved that the reaction was absolutely forced and irreversible, which can be increasingly characterized as a one-way process. According to the results, SiC accelerated the curing reaction because of the increment of heat transfer into the compound. This phenomenon caused the increment of enthalpy variation of the vulcanization reaction, particularly at the SiC content of 5 phr. The achieved kinetic parameters via fitting an autocatalytic model based on the Sestàk-Berggren model by the Màlek method to describe the kinetics of the curing reaction indicated that the SiC filler had a catalytic effect on the curing reaction of SBR/BR-SiC, particularly after 2.5 phr of the filler.

| S-EPMC10469214 | biostudies-literature

Enhancing Rubber Vulcanization Cure Kinetics: Lowering Vulcanization Temperature by Addition of MgO as Co-Cure Activator in ZnO-Based Cure Activator Systems.

Project description:Vulcanization is a chemical modification of rubber that requires a considerable amount of thermal energy. To save thermal energy, the kinetics of rubber vulcanization should be improved. In this article, the curing properties of rubber vulcanization are thoroughly investigated using the moving die rheometer (MDR) technique. To enhance the kinetics in different stages of ZnO-based sulfur vulcanization systems, small amounts of MgO were added. The results revealed that the small amount of 1 to 2 phr (per hundred grams of rubber) of MgO in the controlled 5 phr ZnO-based curing systems can significantly improve the curing kinetics. For example, the optimum curing time of 1 phr MgO added to the 5 phr ZnO-containing semi-efficient vulcanization system at different temperatures was more than half that of the controlled 5 phr ZnO-only compound. While maintaining a similar rate of vulcanization, the vulcanization temperature can be reduced by up to 20 °C by using MgO as a co-cure activator, which exhibits similar or better rheometric mechanical properties compared to the controlled compounds. With the addition of MgO as a co-cure activator, the vulcanization reactions become very fast, enabling vulcanization to be completed, even at the boiling point of water (100 °C) with an affordable curing time (<1 h). By reducing the vulcanization temperature, the scorch safety time can be enhanced in the ZnO/MgO-based binary cure activator-containing vulcanizates. Overall, MgO could be a potential candidate as a co-cure activator with ZnO for the vulcanization of rubber, offering better economical and eco-friendly methods.

| S-EPMC11013655 | biostudies-literature

Catalytic-site design for inverse heavy-enzyme isotope effects in human purine nucleoside phosphorylase.

Project description:Heavy-enzyme isotope effects (15N-, 13C-, and 2H-labeled protein) explore mass-dependent vibrational modes linked to catalysis. Transition path-sampling (TPS) calculations have predicted femtosecond dynamic coupling at the catalytic site of human purine nucleoside phosphorylase (PNP). Coupling is observed in heavy PNPs, where slowed barrier crossing caused a normal heavy-enzyme isotope effect (kchemlight/kchemheavy > 1.0). We used TPS to design mutant F159Y PNP, predicted to improve barrier crossing for heavy F159Y PNP, an attempt to generate a rare inverse heavy-enzyme isotope effect (kchemlight/kchemheavy < 1.0). Steady-state kinetic comparison of light and heavy native PNPs to light and heavy F159Y PNPs revealed similar kinetic properties. Pre-steady-state chemistry was slowed 32-fold in F159Y PNP. Pre-steady-state chemistry compared heavy and light native and F159Y PNPs and found a normal heavy-enzyme isotope effect of 1.31 for native PNP and an inverse effect of 0.75 for F159Y PNP. Increased isotopic mass in F159Y PNP causes more efficient transition state formation. Independent validation of the inverse isotope effect for heavy F159Y PNP came from commitment to catalysis experiments. Most heavy enzymes demonstrate normal heavy-enzyme isotope effects, and F159Y PNP is a rare example of an inverse effect. Crystal structures and TPS dynamics of native and F159Y PNPs explore the catalytic-site geometry associated with these catalytic changes. Experimental validation of TPS predictions for barrier crossing establishes the connection of rapid protein dynamics and vibrational coupling to enzymatic transition state passage.

| S-EPMC5488955 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data