Month: December 2022

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

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

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

Lei, Zhihui published the artcileThermal pyrolysis characteristics and kinetics of hemicellulose isolated from Camellia Oleifera Shell, Application of (2R,3S,4S,5R)-2,3,4,5,6-Pentahydroxyhexanal, the main research area is Camellia Oleifera shell hemicellulose extraction thermal decomposition kinetics; Camellia Oleifera Shell; Hemicelluloses; Kinetic; Pyrolysis; Thermogravimetric analysis.

Camellia Oleifera Shell (COS) is a kind of renewable lignocellulose resource and contains abundant hemicelluloses. In this work, the hemicelluloses in COS were extracted by alkali treatment and precipitated by ethanol with different concentration Thermal pyrolysis kinetics of COS hemicelluloses were investigated using a thermogravimetric analyzer at the heating rates of 5, 10, and 20 °C/min based on Coats-Redfern, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) model. The results showed that the best fitting thermal pyrolysis mechanism of COS hemicelluloses was one-dimensional diffusion reaction analyzed by Coats-Redfern model. The activation energies of COS hemicelluloses ranged from 175.07 to 247.87 kJ·mol-1 and from 174.74 to 252.50 kJ·mol-1 calculated by FWO and KAS, resp. The thermal stabilities of COS hemicelluloses were enhanced with the precipitated ethanol concentration increasing, and reflected by thermodn. parameters ΔH, ΔG and ΔS. This study may provide basic theor. supports for the thermochem. conversion of COS hemicelluloses.

Bioresource Technology published new progress about Activation energy. 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, Application of (2R,3S,4S,5R)-2,3,4,5,6-Pentahydroxyhexanal.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Zhang, Huan published the artcileRecyclable, Self-Healing, Thermadapt Triple-Shape Memory Polymers Based on Dual Dynamic Bonds, Safety of Pentaerythritol tetra(3-mercaptopropionate), the main research area is recyclable self healing thermadapt triple shape memory dynamic bond; butadiene rubber modified double bond dynamic; dynamic bond; recyclability; self-healing; solid-state plasticity; triple-shape memory.

Fabricating a single polymer network with a combination of a multi-shape memory effect (multiple-SME), solid-state plasticity, recyclability and self-healing behavior remains a challenge. We designed imine bond and ionic hydrogen bond dual crosslinked polybutadiene (PB) networks. The resulting PB networks showed a triple-shape memory effect, where imine bonds could be used to fix the permanent shape and ionic hydrogen bonds and glass transition acted as the transition segments for fixing/releasing the temporary shapes. Addnl., the dual dynamic bonds offered PB networks outstanding solid-state plasticity, recyclability and self-healing behavior. This strategy provides some insights for preparing shape memory polymers integrating multiple-SME and multi-functionality.

ACS Applied Materials & Interfaces 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, Safety of Pentaerythritol tetra(3-mercaptopropionate).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Lin, Xueyan published the artcileImine-Based Reactive Mesogen and Its Corresponding Exchangeable Liquid Crystal Elastomer, Formula: C17H28O8S4, the main research area is imine reactive mesogen corresponding exchangeable liquid crystal elastomer.

To date, exchangeable liquid crystalline elastomers (xLCEs) are mainly fabricated by combining conventional LCEs with addnl. exchangeable functional groups in their networks. While conventional LCEs are frequently made from com. available aromatic-ester reacting mesogens, or from mesogens based on biphenyl core, such reacting monomers are not optimized to fabricating xLCEs whose bond-exchange reaction is fast and clean-cut. Here, we develop a fast synthesis route to produce a new type of reactive mesogen based on an aromatic-imine structure that intrinsically enables a fast and stable bond-exchange reaction in the resulting imine-based xLCE. This new xLCE displays vitrimer plastic-flow behavior and its bond-exchange activation energy is calculated to be 54 kJ/mol. We also demonstrate that this xLCE is thermally stable, to withstand many recycling cycles without visible decay, and its liquid crystallinity is preserved. Finally, we demonstrate the reprogramming and realignment of mesogen orientation in this xLCE, with the realigned xLCE capable of reversible thermal actuation.

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

Li, Qiong published the artcileConcurrent thiol-ene competitive reactions provide reprocessable, degradable and creep-resistant dynamic-permanent hybrid covalent networks, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate), the main research area is polythioacetal polythioether green chem degradation creep resistance recycling thermostability.

A catalyst-free, solvent-free thiol-ene addition reaction was developed to produce a dynamic-permanent hybrid cross-linked polymer from two simple components, a tetrathiol and a divinyl ether, in one pot. The tetrathiol and divinyl ether underwent two competitive Markovnikov and anti-Markovnikov addition reactions simultaneously and sep. generated S,O-thioacetal cross-links and thioether cross-links. The dynamic feature of S,O-thioacetal cross-links imparts excellent malleability, reprocessability and degradability to the obtained network, and the permanent covalent thioether cross-links provide favorable high-temperature creep resistance. This work will broaden the thiol-ene chem. and provide a green method to achieve recyclable cross-linked polymers and covalent adaptable networks (CANs) or vitrimer-like materials with high-temperature creep resistance.

Green 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, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Chen, Kai published the artcileA semi-interpenetrating network polymer electrolyte membrane prepared from non-self-polymerized precursors for ambient temperature all-solid-state lithium-ion batteries, Computed Properties of 7575-23-7, the main research area is PEG semi interpenetrating network electrolyte membrane lithium battery.

Solid polymer electrolytes (SPEs) are currently attracting widespread interest for lithium battery applications due to high safety, low volatility, and the ability to suppress Li dendrites. Herein, a novel all-solid-state polymer electrolyte with semi-interpenetrating network (semi-IPN) structure has been prepared The semi-IPN SPE is fabricated by thiol-tosylate polycondensation of pentaerythritol terakis (3-mercaptopropionate) (PETMP) with non-self-polymerized precursors, ditosylate poly (ethylene glycol) (DTsPEG) and p-toluenesulfonyl poly (ethylene glycol) Me ether (TsPEGME), and then blended with a high mol. weight polyethylene oxide (PEO, Mw = 300 kg mol-1). The resulting self-standing membrane achieves an excellent ionic conductivity (1.3 x 10-4 S cm-1) at ambient temperature, and exhibits an electrochem. stability window up to 4.3 V vs. Li/Li+. The LiFePO4/semi-IPN-SPE/Li battery exhibits a first discharging capacity of 143.1 mA h g-1 at 0.2C and the discharge capacity keeps 134 mA h g-1 after 100 charge and discharge cycles.

Journal of Solid State 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, Computed Properties of 7575-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Grewal, Manjit Singh published the artcileBifunctional poly(ethylene glycol) based crosslinked network polymers as electrolytes for all-solid-state lithium ion batteries, SDS of cas: 7575-23-7, the main research area is PEG crosslinked network polymer solid state lithium ion battery.

Polymer electrolyte based lithium ion batteries represent a revolution in the battery community due to their intrinsic enhanced safety, and as a result polymer electrolytes have been proposed as a replacement for conventional liquid electrolytes. Herein, the preparation of a family of crosslinked network polymers as electrolytes via the ‘click-chem.’ technique involving thiol-ene or thiol-epoxy is reported. These network polymer electrolytes comprise bifunctional poly(ethylene glycol) as the lithium ion solvating polymer, pentaerythritol tetrakis (3-mercaptopropionate) as the crosslinker and lithium bis(trifluoromethane)sulfonimide as the lithium salt. The crosslinked network polymer electrolytes obtained show low Tg, high ionic conductivity and a good lithium ion transference number (ca 0.56). In addition, the membrane demonstrated sterling mech. robustness and high thermal stability. The advantages of the network polymer electrolytes in this study are their harmonious characteristics as solid electrolytes and the potential adaptability to improve performance by combining with inorganic fillers, ionic liquids or other materials. In addition, the simple formation of the network structures without high temperatures or light irradiation has enabled the practical large-area fabrication and in situ fabrication on cathode electrodes. As a preliminary study, the prepared crosslinked network polymer materials were used as solid electrolytes in the elaboration of all-solid-state lithium metal battery prototypes with moderate charge-discharge profiles at different current densities leaving a good platform for further improvement. © 2018 Society of Chem. Industry.

Polymer International 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

Meng, Xiaorong published the artcileStudy on stable mass transfer and enrichment of phenol by 1-octanol/kerosene/polyvinyl chloride polymer inclusion membrane, SDS of cas: 111-87-5, the main research area is octanol polyvinyl chloride kerosene liquid paraffin phenol mass transfer; 1-Octanol; Mass transfer; Phenol; Polymer inclusion membrane; Stability.

A polymer inclusion membrane (PIM) that contains a polyvinyl chloride (PVC) polymer matrix and 1-octanol (OCT) as specific carrier (PO-PIM) was prepared to investigate the mass transfer behavior of phenol in aqueous solutions Results showed that the mass transfer behavior of the PO-PIM for phenol conformed to the first-order kinetics. In addition, the mass transfer efficiency for phenol reached the maximum when the OCT content was 82.8 wt%. The mass transfer activation energy (Ea) was 14.46 kJ mol-1, which indicated that intramembranous diffusion was the main controlling factor in the mass transfer process. The introduction of hydrophobic additives, such as kerosene, liquid paraffin and vegetable oil, into the PO-PIM could remarkably improve its stability. In an aqueous solutions of phenol ranging from 0 mg L-1 to 9000 mg L-1, the initial flux (J0) of kerosene/PVC/OCT-PIM (KPO-PIM) was pos. correlated with the initial concentration of phenol. For a stripping solution with a feed solution pH of 2.0 and a sodium hydroxide concentration of 0.1 mol L-1, the maximum permeability coefficient during stable mass transfer reached 12.55μm s-1. At a mass transfer area of 3.14 cm2, an enrichment factor (EF) of 3.5 for 200 mg L-1 of phenolic aqueous solution was achieved within 48 h through KPO-PIM.

Environmental Pollution (Oxford, United Kingdom) 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, SDS of cas: 111-87-5.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts