Tag: M.W=400-500

Podgorski, Maciej published the artcileMixed mechanisms of bond exchange in covalent adaptable networks: monitoring the contribution of reversible exchange and reversible addition in thiol-succinic anhydride dynamic networks, HPLC of Formula: 7575-23-7, the main research area is thiol succinic anhydride dynamic network bond exchange mechanism property.

Dynamic photopolymer networks that take advantage of the thermodynamically controlled reversibility of thiol-succinic anhydride adducts were synthesized from com. substrates and investigated as a new class of covalent adaptable networks (CANs). Through systematic studies of the catalyst and stoichiometry effects on the exchange dynamics two distinctive exchange mechanisms were found, and then demonstrated to contribute to the overall dynamic characteristics. By varying the catalyst activity, i.e. basicity and/or nucleophilicity, control over the dynamic responsiveness through changes in the type of dynamic covalent chem. mode (reversible addition vs. reversible exchange) was achieved in otherwise compositionally analogous materials. More specifically, the participation of the associative mechanism (thiol-thioester exchange) in the otherwise dissociative networks, and its relevance on materials properties was demonstrated by dielec. anal. (DEA) and dynamic mech. anal. (DMA). The activation energies (Ea) for viscous flow obtained from DMA stress relaxation experiments and from dielec. modulus and loss crossover points were shown to match well between the two techniques. The Ea in stoichiometric systems was found to be 110-120 kJ mol-1, whereas 50% excess thiol systems were characterized by Ea ranging 95-105 kJ mol-1. The thermodn. equilibrium conversion, estimated in the temperature controlled FTIR, for a stoichiometric 3-mercaptopropionate-succinic anhydride combination was determined at 92 ± 1% at ambient temperature, and decreased to 67 ± 1% at 120°C within one hour of equilibration time (ΔH° = -46 ± 5 kJ mol-1). Such high potential for reversibility of the thioester anhydride linkages resembles maleimide-furan diels-alder networks but has many other attributes that make these CANs of unprecedented value in fundamental research on dynamic materials.

Polymer Chemistry published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, HPLC of Formula: 7575-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Podgorski, Maciej published the artcileThiol-Anhydride Dynamic Reversible Networks, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate), the main research area is thiol anhydride photopolymer stress relaxation dynamic network; covalent adaptable networks; dynamic composites; photopolymers; recycling; stress relaxation.

The reaction of thiols and anhydrides to form ring opened thioester/acids is shown to be highly reversible and it is accordingly employed in the fabrication of covalent adaptable networks (CANs) that possess tunable dynamic covalent chem. Maleic, succinic, and phthalic anhydride derivatives were used as bifunctional reactants in systems with varied stoichiometries, catalyst, and loadings. Dynamic characteristics such as temperature-dependent stress relaxation, direct reprocessing and recycling abilities of a range of thiol-anhydride elastomers, glasses, composites and photopolymers are discussed. Depending on the catalyst strength, 100% of externally imposed stresses were relaxed in the order of minutes to 2 h at mild temperatures (80-120°C). Pristine properties of the original materials were recovered following up to five cycles of a hot-press reprocessing technique (1 h/100°C).

Angewandte Chemie, International Edition published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Moradi, Sasan published the artcileEpoxy composites filled with boron nitride: cure kinetics and the effect of particle shape on the thermal conductivity, SDS of cas: 7575-23-7, the main research area is epoxy resin boron nitride composite particle size thermal conductivity.

Thermally conducting and elec. insulating materials have been prepared by filling an epoxy-thiol system with boron nitride (BN) particles of different shapes (platelets and agglomerates) and sizes (from 2 to 180μm), and hence with different sp. surface areas. The cure kinetics has been studied by differential scanning calorimetry in both non-isothermal and isothermal modes, and it has been shown that there is a systematic dependence of the cure kinetics on the BN content, the cure reaction generally being retarded by the addition of the BN particles. For filler loadings greater than about 30 vol%, the retardation of the cure, in both isothermal and non-isothermal mode, appears also to decrease as the sp. surface area decreases. For the smallest (2μm) platelets, which have a significantly higher sp. surface area (10 m2 g-1), the retardation is particularly pronounced, and this aspect is rationalized in terms of the activation energy and frequency factor of the reaction. The agglomerates, though, give the highest values of thermal conductivity, contrary to what might be expected in the light of their sp. surface areas. SEM of the fracture surfaces of the cured composites has been used to show that the interface between epoxy matrix and filler particles is better for the agglomerates. This, together with the reduced interfacial area, explains their higher thermal conductivity

Journal of Thermal Analysis and Calorimetry published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, SDS of cas: 7575-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Stalin, Sanjuna published the artcileAchieving uniform lithium electrodeposition in cross-linked poly(ethylene oxide) networks: “”soft”” polymers prevent metal dendrite proliferation, Name: Pentaerythritol tetra(3-mercaptopropionate), the main research area is lithium electrodeposition crosslinked polyethylene oxide electrolyte.

Lithium electrodeposition in uniformly porous, nanostructured media formed in cross-linked poly(ethylene oxide) polymer networks enabled by thiol-ene click chem were investigated. Using galvanostatic strip-plate experiments along with SEM and operando visualization techniques, we critically assess the effectiveness of these materials in enabling uniform, planar deposition of lithium. Thiol-ene click networks that host a liquid electrolyte in their pores are more effective than their liquid electrolyte or solid polymer network components in regulating Li deposition at both the nucleation and growth phases. It is shown further that compressive interfacial stresses imparted by the networks during electrodeposition may serve to augment surface tension to enable uniform Li electrodeposition. The practical relevance of these electrolytes is demonstrated in full-cell battery configurations with excellent long-term stability.

Macromolecules (Washington, DC, United States) published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Name: Pentaerythritol tetra(3-mercaptopropionate).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Isogai, Taketo published the artcileCritical Effects of Branch Numbers at the Cross-Link Point on the Relaxation Behaviors of Transesterification Vitrimers, COA of Formula: C17H28O8S4, the main research area is relaxation behavior transesterification vitrimer.

Vitrimers are functional crosslinked materials, exhibiting reprocessability, recyclability, and healability, and thus these are expected for application as sustainable materials. The functionalities of vitrimers are attributable to their associative bond exchange mechanism that is activated at a certain high temperature The construction of a tuning method for the bond exchange properties must be useful for coming practical application of the vitrimer concept. Here, we prepare transesterification-based vitrimers via the thiol-epoxy click reaction to elucidate the essential effects of the branch numbers (f) at the crosslink point on their bond exchange properties, where f can be readily tuned via the functionality of the starting materials. The temperature-ramp creep and stress-relaxation tests then demonstrate that the vitrimer properties, such as the softening and stress-relaxation behaviors, vary depending on f. The exptl. results derive some empirical relationships between f and the relaxation time and between f and activation energy of the bond exchange. In addition, the relaxation behavior of the vitrimer network with mixed f is investigated in the final section, showing the relaxation rate can be determined by the harmonic mean of relaxation time weighted by the mole fraction of the network components having different f. Overall, this study demonstrates that the design of a proper f is crucial to obtain the desired properties of vitrimers.

Macromolecules (Washington, DC, United States) published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, COA of Formula: C17H28O8S4.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Bongiardina, Nicholas J. published the artcileSubstituted Thiols in Dynamic Thiol-Thioester Reactions, Formula: C17H28O8S4, the main research area is thiol dynamic thioester.

The thiol-thioester reaction has emerged as a promising method for developing covalent adaptable networks (CANs) due to its ability to exchange rapidly under low temperature conditions in a number of solvents, orthogonality among other functional groups, and tunability. Here, the effects of thiol substitution (i.e., primary vs secondary) were assessed with respect to their reactivity in two dynamic thioester reactions: the thiol-thioester exchange and the reversible thiol-anhydride addition Model NMR experiments were conducted using small-mol. compounds to observe how polymers of similar components would behave in thiol-thioester exchange. It was determined that the Keq was near unity for mixtures of primary thiols and secondary thioesters, and vice versa, in both a polar solvent, DMSO-d6, and at most slightly favors primary thioesters in a relatively nonpolar solvent, CDCl3. Dielec. spectroscopy and stress relaxation experiments were used to determine the relaxation times and activation energies of the two thioester-containing networks: Thiol-ene networks, which undergo thioester exchange, displayed activation energies of 73 and 71 kJ/mol from dielec. measurements and 36 and 53 kJ/mol from stress relaxation for the primary and secondary thiols, resp. Thiol-anhydride-ene networks, which undergo both thioester exchange and reversible thiol-anhydride addition, displayed activation energies of 94 and 114 kJ/mol from dielec. and 111 and 139 kJ/mol from stress relaxation for primary and secondary thiols, resp. In both types of networks, the secondary thioester-based networks demonstrated slower dynamics as compared to the same primary network by at least one order of magnitude. In the anhydride network, the secondary thiol also biased the dynamics toward reversible addition

Macromolecules (Washington, DC, United States) published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Formula: C17H28O8S4.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Tahka, Sari published the artcileImmobilization of proteolytic enzymes on replica-molded thiol-ene micropillar reactors via thiol-gold interaction, Synthetic Route of 7575-23-7, the main research area is chymotrypsin immobilization micropillar reactor; Enzyme immobilization; Gold nanoparticles; Mass spectrometry; Microfluidics; Microreactors; Thiol-enes.

We introduce rapid replica molding of ordered, high-aspect-ratio, thiol-ene micropillar arrays for implementation of microfluidic immobilized enzyme reactors (IMERs). By exploiting the abundance of free surface thiols of off-stoichiometric thiol-ene compositions, we were able to functionalize the native thiol-ene micropillars with gold nanoparticles (GNPs) and these with proteolytic α-chymotrypsin (CHT) via thiol-gold interaction. The micropillar arrays were replicated via PDMS soft lithog., which facilitated thiol-ene curing without the photoinitiators, and thus straightforward bonding and good control over the surface chem. (number of free surface thiols). The specificity of thiol-gold interaction was demonstrated over allyl-rich thiol-ene surfaces and the robustness of the CHT-IMERs at different flow rates and reaction temperatures using bradykinin hydrolysis as the model reaction. The product conversion rate was shown to increase as a function of decreasing flow rate (increasing residence time) and upon heating of the IMER to physiol. temperature Owing to the effective enzyme immobilization onto the micropillar array by GNPs, no further purification of the reaction solution was required prior to mass spectrometric detection of the bradykinin hydrolysis products and no clogging problems, commonly associated with conventional capillary packings, were observed The activity of the IMER remained stable for at least 1.5 h (continuous use), suggesting that the developed protocol may provide a robust, new approach to implementation of IMER technol. for proteomics research. [Figure not available: see fulltext.].

Analytical and Bioanalytical Chemistry published new progress about Enzymic hydrolysis. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Synthetic Route of 7575-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Ma, Huali published the artcileIn Situ Self-Assembly of Ultrastable Crosslinked Luminescent Gold Nanoparticle and Organic Dye Nanohybrids toward Ultrasensitive and Reversible Ratiometric Thermal Imaging, Computed Properties of 7575-23-7, the main research area is crosslinked luminescent gold nanoparticle organic dye nanohybrid thermal imaging.

Exploring hybrid nanomaterials with sensitive and reversible ratiometric temperature sensing is highly desirable but still challenging. Herein, using thermosensitive Pluronic F127 as template, a facile and straightforward approach is presented for one-pot synthesis of dual-emitting nanohybrids of crosslinked gold nanoparticle (AuNP) and organic dye with unique core-shell structure and excellent stability, which can be utilized as an ultrasensitive and reversible ratiometric temperature sensor. The dual-emitting nanohybrids are achieved through in situ self-assembly of red-emitting AuNPs in the hydrophobic core, along with doping blue-emitting and polarity-responsive hydrophobic dye 4,4′-bis(2-benzoxazolyl) stilbene (BBS). The AuNP and BBS nanohybrids (AuNP-BBS nanohybrids) consist of about ten crosslinked ultrasmall AuNPs in the hydrophobic core. The crosslinking interaction between multidentate thiol ligand and ultrasmall AuNPs offers remarkable stability without dye leakage, while the thermosensitive Pluronic F127 endows the nanohybrids with two reverse signal responses toward temperature By virtue of the excellent features, the dual-emitting AuNP-BBS nanohybrids can be capable of ratiometric sensing of temperature with remarkable reversibility and high sensitivity (0.3396°C-1), and enable visual temperature measurements by the naked eye and pseudocolor imaging. These findings provide a useful guidance for preparing uniform hybrid nanomaterials with remarkable stability and desired functions.

Advanced Optical Materials published new progress about Fluorescence decay. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Computed Properties of 7575-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Xiang, Hongping published the artcilePhoto-crosslinkable, self-healable and reprocessable rubbers, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate), the main research area is photocrosslinking self healing reprocessable butadiene rubber polysulfide.

As a proof of concept, this study reports a facile method to prepare photo-crosslinkable, self-healable and reprocessable rubbers, which are rapidly crosslinked and patterned variform products via thiol-ene photoclick polymerization between the double bonds in polybutadiene and thiols in polysulfide. Disulfide linkages in polysulfide can dynamically rearrange the crosslinked networks through UV irradiation activated disulfide metathesis. The model small mol. experiments prove that disulfide metathesis is efficiently promoted by UV light and inclines to second-order reaction. The stress of photo-crosslinked rubbers is almost completely relaxed under UV irradiation at higher than 25 mW/cm2. More interestingly, stress relaxation can be controlled by sequentially turning on/off UV light. The self-adhesion assisted self-healing property is revealed by repeated tensile shear tests. The content of disulfide bonds, transmittance, irradiation intensity and time have a synergistic effect on the self-healing ability. The healed samples can regain higher than 90% shear strength, and the efficiency is not significantly influenced by repeated healing. Due to the dynamic reversibility of disulfide metathesis, the molded rubbers can be transformed into other shapes under UV illumination. Moreover, the pulverized rubber can also be compressed into new items by means of UV induced disulfide metathesis. This study thus illustrates a feasible approach to endow photo-cured rubbers with UV triggered self-healing and reprocessing capacities.

Chemical Engineering Journal (Amsterdam, Netherlands) published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Deng, Kuirong published the artcileFlame-retardant single-ion conducting polymer electrolytes based on anion acceptors for high-safety lithium metal batteries, Computed Properties of 7575-23-7, the main research area is conducting polymer electrolyte anion acceptor lithium metal battery.

Solid-state lithium metal batteries (LMBs) assembled with polymer electrolytes (PEs) and lithium metal anodes are promising batteries owing to their enhanced safety and ultrahigh theor. energy densities. Nevertheless, polymer electrolytes (PEs) suffer from low ionic conductivities, low lithium-ion transference numbers (LITNs) and high flammability. To address these issues, a novel nonflammable single-ion conducting polymer electrolyte (AEP) with ultrahigh ionic conductivity, unity LITN, excellent flame retardance and high flexibility has been developed. Allylboronic acid pinacol ester (AAPE) is incorporated into the 3D crosslinking network of AEP to act as the anion acceptor that traps the anions, improving the LITN to 0.79. AEP possesses an ultrahigh ionic conductivity of 2.52 mS cm-1 at 25°C. AEP cannot be ignited by flame. AEP can construct robust LiF-rich SEIs on lithium metal anodes and effectively suppress dendrite growth. LiFePO4 cells assembled with AEP demonstrate excellent rate capacity (specific capacity of 112.4 mA h g-1 at 5C rate) and long-term cycling stability (93.2% capacity retention after 500 cycles). This work provides a promising approach to prepare new PEs for high-safety, high-stability and high-energy LMBs.

Journal of Materials Chemistry A: Materials for Energy and Sustainability published new progress about Activation energy. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Computed Properties of 7575-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts