Category: alcohols-buliding-blocks

Mansouri, Mahsa published the artcileGas permeation properties of highly cross-linked castor oil-based polyurethane membranes synthesized through thiol-yne click polymerization, Related Products of alcohols-buliding-blocks, the main research area is gas permeation castor oil polyurethane membrane.

In this paper, a new chem. approach was developed for synthesis of castor oil (CO)-based polyurethane (PU) membranes to attain improved structural properties for gas separation applications. For this purpose, propyne-terminated CO-based PU prepolymer (PTPU) was synthesized by the reaction of CO and isophorone diisocyanate (IPDI), followed by propargyl alc. (PrAl) and isocyanate (NCO) terminated prepolymer reaction. The ultimate membranes were prepared through thiol-yne crosslinking reaction of PTPU and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP), in presence of azobisisobutyronitrile (AIBN), as a reaction initiator. It was revealed that mech. and thermal properties of the prepared membranes were improved owing to the formation of flexible thioether linkages through crosslinking reaction. The gas permeation measurements were carried out in the temperature and pressure ranges of 298-338 K and 200-1200 kPa, resp. The results exhibited reverse size selective performance, as a typical transport behavior of rubbery membranes. The infinite dilution permeability coefficient of CO2 at 298 K was found identical to 2.78 Barrer, along with the infinite dilution perm-selectivity values for CO2/CH4 and CO2/H2 obtained equal to 25.27 and 7.94, resp. Furthermore, higher permeation activation energies were found in this work compared to a number of crosslinked rubbery membranes in the literature, such as poly (dimethylsiloxane) (PDMS) and poly(ethylene glycol) diacrylate (PEGDA).

Reactive & Functional Polymers 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, Related Products of alcohols-buliding-blocks.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Gablier, Alexandra published the artcileRates of transesterification in epoxy-thiol vitrimers, Product Details of C17H28O8S4, the main research area is epoxy thiol vitrimer transesterification elastomer thermal mech property.

Vitrimers, an important subset of dynamically crosslinked polymer networks, have many technol. applications for their excellent properties, and the ability to be re-processed through plastic flow above the so-called vitrification temperature We report a simple and efficient method of generating such adaptive crosslinked networks relying on transesterification for their bond exchange by utilizing the ‘click’ chem. of epoxy and thiols, which also has the advantage of a low glass transition temperature We vary the chem. structure of thiol spacers to probe the effects of concentration and the local environment of ester groups on the macroscopic elastic-plastic transition. The thermal activation energy of transesterification bond exchange is determined for each chem. structure, and for a varying concentration of catalyst, establishing the conditions for the optimal, and for the suppressed bond exchange. However, we also discover that the temperature of elastic-plastic transition is strongly affected by the stiffness (dynamic rubber modulus) of the network, with softer networks having a much lower vitrification temperature even when their bond-exchange activation energy is higher. This combination of chem. and phys. control factors should help optimize the processability of vitrimer plastics.

Soft Matter 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, Product Details of C17H28O8S4.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

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

Abedsoltan, Hossein published the artcileAryl sulfonic acid catalysts: Effect of pendant group structure on activity in hydrolysis of polyethylene terephthalate, HPLC of Formula: 111-87-5, the main research area is aryl sulfonic acid catalyst hydrolysis polyethylene terephthalate.

A series of aryl sulfonic acids were tested as catalysts for acid hydrolysis occurring at the surface of poly(ethylene) terephthalate (PET) particles. Specifically, p-toluenesulfonic acid monohydrate (PTSA), 2-naphthalenesulfonic acid (2-NSA), and 1,5-naphthalenedisulfonic acid tetrahydrate (1,5-NDSA) were chosen to provide sulfonic acid active groups and varying hydrophobic func tionality. The effect of catalyst concentration and reaction temperature on PET hydrolysis rate was studied. The aryl sulfonic acid catalysts exhibited much higher rates of PET hydrolysis than the mineral acid, H2SO4. At 150°C and 4 M catalyst, the time required to achieve more than 90% TPA yield was 3, 3, and 8 h, and 18 h for (PTSA), (2-NSA), (1,5-NDSA), and H2SO4, resp. Et acetate hydrolysis was performed as a model reaction to probe the activity of the catalysts in homogenous reactions to compare with the heterogeneous hydrolysis reaction occurring at the PET surface. The higher catalytic activities for PET hydrolysis of the PTSA, 2-NSA, and 1,5-NDSA than H2SO4 was attributed to improved wetting by the reaction media and affinity of the aryl sulfonic acid catalysts for the PET surface.

Journal of Applied Polymer Science published new progress about Activation energy. 111-87-5 belongs to class alcohols-buliding-blocks, name is n-Octanol, and the molecular formula is C8H18O, HPLC of Formula: 111-87-5.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Coff, Lachlan published the artcileIdentifying glycan motifs using a novel subtree mining approach, Name: (2R,3S,4S,5R)-2,3,4,5,6-Pentahydroxyhexanal, the main research area is glycan motif subtree mining algorithm; Carbohydrate; Frequent subtree mining; Glycan; Glycobiology; Machine learning; Microarray; Motif.

Glycans are complex sugar chains, crucial to many biol. processes. By participating in binding interactions with proteins, glycans often play key roles in host-pathogen interactions. The specificities of glycan-binding proteins, such as lectins and antibodies, are governed by motifs within larger glycan structures, and improved characterisations of these determinants would aid research into human diseases. Identification of motifs has previously been approached as a frequent subtree mining problem, and we extend these approaches with a glycan notation that allows recognition of terminal motifs. In this work, we customised a frequent subtree mining approach by altering the glycan notation to include information on terminal connections. This allows specific identification of terminal residues as potential motifs, better capturing the complexity of glycan-binding interactions. We achieved this by including addnl. nodes in a graph representation of the glycan structure to indicate the presence or absence of a linkage at particular backbone carbon positions. Combining this frequent subtree mining approach with a state-of-the-art feature selection algorithm termed min.-redundancy, maximum-relevance (mRMR), we have generated a classification pipeline that is trained on data from a glycan microarray. When applied to a set of commonly used lectins, the identified motifs were consistent with known binding determinants. Furthermore, logistic regression classifiers trained using these motifs performed well across most lectins examined, with a median AUC value of 0.89. We present here a new subtree mining approach for the classification of glycan binding and identification of potential binding motifs. The Carbohydrate Classification Accounting for Restricted Linkages (CCARL) method will assist in the interpretation of glycan microarray experiments and will aid in the discovery of novel binding motifs for further exptl. characterization.

BMC Bioinformatics published new progress about Agaricus bisporus. 59-23-4 belongs to class alcohols-buliding-blocks, name is (2R,3S,4S,5R)-2,3,4,5,6-Pentahydroxyhexanal, and the molecular formula is C6H12O6, Name: (2R,3S,4S,5R)-2,3,4,5,6-Pentahydroxyhexanal.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts