Month: December 2022

Prathima, P. Sai published the artcileCuI/L-proline-catalyzed selective one-step mono-acylation of styrenes and stilbenes, Quality Control of 92093-23-7, the main research area is monoacylated diol preparation copper proline catalyst; styrene stilbene vicinal dioxygenation copper proline catalyst.

Vicinal di-oxygenation of styrene-type olefins was achieved with cheaper, less toxic CuI in the presence of L-proline as ligand and NaIO4 as the oxidant. This approach provides a straightforward and efficient access to mono-acylated diols from both styrene and stilbene derivatives with good to excellent yields and diastereoselectivity.

Tetrahedron Letters published new progress about Acylation. 92093-23-7 belongs to class alcohols-buliding-blocks, name is 1-(4-Bromophenyl)ethane-1,2-diol, and the molecular formula is C8H9BrO2, Quality Control of 92093-23-7.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Qiu, Jiaqi published the artcileRecyclable DMAP-Functionalized polymeric nanoreactors for highly efficient acylation of alcohols in aqueous systems, Synthetic Route of 584-02-1, the main research area is DMAP functionalize block copolymer preparation thermal stability; alc anhydride heterogeneous catalyst acylation green chem; ester preparation.

In this study, small-mol. catalysts 4-(N,N-dimethylamino)pyridine (DMAP) functionalized nanoreactors were constructed by self-assembly of amphiphilic block copolymers with DMAP moieties in the hydrophobic block, leading to heterogeneous catalysts with excellent dispersity in water. The key preparation route included reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-(N-methyl-N-(4-pyridyl)amino)ethyl methacrylate (MAPMA) and Me methacrylate (MMA) using poly (oligomeric (ethylene glycol) Me ether methacrylate) (POEGMA) as a hydrophilic macromol. RAFT reagent. The characterization by dynamic light scattering (DLS) and transmission electron microscopy (TEM) shows that the nanoreactors possess a core-shell nanostructure with the diameter of around 110 nm. The resulting polymeric nanoreactors showed excellent catalytic activity for acylation of alcs. in water. High conversion of a variety of alc. (>99%) and excellent product selectivity were achieved. The high catalytic efficiency of the nanoreactors may be attributed to the enhancement of the interaction between the reactant and the catalyst in the confined hydrophobic space, which simulates how enzymes usually work. Moreover, the catalyst was easily recovered by thermoresponsive separation and reused with high activity for more than 5 cycles. This study presents an efficient approach to achieve green catalytic reactions which were normally incompatible to aqueous conditions, potentially applicable to other catalytic systems such as metal-mediated organic transformations.

Polymer published new progress about Acylation. 584-02-1 belongs to class alcohols-buliding-blocks, name is 3-Pentanol, and the molecular formula is C5H12O, Synthetic Route of 584-02-1.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Hayashi, Hiroyuki published the artcileInsight into the Mechanism of the Acylation of Alcohols with Acid Anhydrides Catalyzed by Phosphoric Acid Derivatives, Recommanded Product: rel-(1R,2R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-ol, the main research area is alc acylation carboxylic acid anhydride phosphoric acid derivative catalysis.

Insight into the mechanism of a safe, simple, and inexpensive phosphoric acid (H3PO4)-catalyzed acylation of alcs. with acid anhydrides is described. The corresponding in situ-generated diacylated mixed anhydrides, unlike traditionally proposed monoacylated mixed anhydrides, are proposed as the active species. In particular, the diacylated mixed anhydrides act as efficient catalytic acyl transfer reagents rather than as Bronsted acid catalysts simply activating acid anhydrides. Remarkably, highly efficient phosphoric acid (1-3 mol %)-catalyzed acylation of alcs. with acid anhydrides was achieved and a 23 g scale synthesis of an ester was demonstrated. Also, phosphoric acid catalyst was effective for synthetically useful esterification from carboxylic acids, alcs., and acid anhydride. Moreover, with regard to recent developments in chiral 1,1′-bi-2-naphthol (BINOL)-derived phosphoric acid diester catalysts toward asym. kinetic resolution of alcs. by acylation, some phosphate diesters were examined As a result, a 31P NMR study and a kinetics study strongly supported not only the acid-base cooperative mechanism as previously proposed by other researchers but also the mixed anhydride mechanism as presently proposed by us.

Journal of Organic Chemistry published new progress about Acylation. 124-76-5 belongs to class alcohols-buliding-blocks, name is rel-(1R,2R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-ol, and the molecular formula is C10H18O, Recommanded Product: rel-(1R,2R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-ol.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Chen, Ling published the artcileHealable and Rearrangeable Networks of Liquid Crystal Elastomers Enabled by Diselenide Bonds, Name: Pentaerythritol tetra(3-mercaptopropionate), the main research area is diselanediylbispropanediyl diacrylate crosslinkable liquid crystal elastomer actuator; diselenide bond; dual-mode programmability; liquid crystal elastomer; rearrangeable LCE network.

Based on liquid crystal elastomer (LCE) materials, hierarchically structured soft actuators can meet some requirements for human-friendly working mode and execute complex tasks with intelligent adaptation to environmental changes. However, few researchers have paid much attention to the preparation methods of multicomponent/hierarchical LCE actuators. The authors demonstrate the successful integration of an exchangeable diselenide chain extender for the preparation of dynamic LCEs, which could be reprogrammed on heating or under visible light illumination. Also, the rearrangeable polydiselenide networks could be applied to develop the self-welding technol. toward fabricating hierarchically structured LCE actuators with sophisticated deformability without using any auxiliary reagent (adhesive, tape, catalysts or initiator) during the assembling process.

Angewandte Chemie, International Edition published new progress about Actuators. 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

Chen, Guancong published the artcileA photo-driven metallo-supramolecular stress-free reversible shape memory polymer, Computed Properties of 7575-23-7, the main research area is photo metallo supramol stress free reversible shape memory polyester.

Soft machines can offer remote-powering mechanisms and mech. flexibility unmatched by conventional rigid machines. However, the mol. integration of powering and actuation functions in a simple yet versatile format has remained challenging. We achieve this with a semi-crystalline supramol. metallo-network. The dynamic metallo-bonds offer a flexible mechanism for programming the network anisotropy, which gives rise to stress-free reversible actuation using the crystalline transition as the actuation phase. In addition, the proper choice of metallo-bonds provides suitable photo-thermal capabilities for remote powering without endangering the cyclic actuation stability, despite the supramol. nature. Based on these principles, we illustrate that the supramol. network can be programmed into a reptile-style device remotely powered by light. The molecularly integrated dual functionality based on supramol. metallo-bonds provides an attractive option for the future design of soft machines with sophisticated morphing behaviors yet simple powering mechanisms.

Journal of Materials Chemistry A: Materials for Energy and Sustainability published new progress about Actuators. 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

Yao, Mingyue published the artcileA Highly Robust Ionotronic Fiber with Unprecedented Mechanomodulation of Ionic Conduction, Computed Properties of 7575-23-7, the main research area is ionotronic liquid crystal fiber film elastic ionic conductivity; actuators; ionic conductors; responsive materials; sensors; stretchable electronics.

Stretchable ionic conductors are appealing for tissue-like soft electronics, yet suffer from a tardy mechanoelec. response due to their poor modulation of ionic conduction arising from intrinsic homogeneous soft chain network. Here, a highly robust ionotronic fiber is designed by synergizing ionic liquid and liquid crystal elastomer with alternate rigid mesogen units and soft chain spacers, which shows an unprecedented strain-induced ionic conductivity boost (≈103 times enhanced as stretched to 2000% strain). Such a surprisingly high enhancement is attributed to the formation of microphase-separated low-tortuosity ion-conducting nanochannels guided by strain-induced emergence of aligned smectic mesophases, thus allowing for ultrafast ion transport that resembles the role of swimming lanes. Intriguingly, the boosting conductivity even reverses Pouillet’s Law-dictated resistance increase at certain strains, leading to unique waveform-discernible strain sensing. Also, the fiber retains thermal actuation properties with a maximum of 70% strain changes upon heating, and enables integrated self-perception and actuation. The findings offer a promising mol. engineering route to mech. modulate transport behavior of ionic conductors toward advanced ionotronic applications.

Advanced Materials (Weinheim, Germany) published new progress about Actuators. 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

Ford, Michael J. published the artcileA multifunctional shape-morphing elastomer with liquid metal inclusions, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate), the main research area is liquid crystal elastomer metal composite thermal elec mech property; conductive elastomer; liquid crystal elastomer; liquid metal; shape memory; soft actuator.

Natural soft tissue achieves a rich variety of functionality through a hierarchy of mol., microscale, and mesoscale structures and ordering. Inspired by such architectures, we introduce a soft, multifunctional composite capable of a unique combination of sensing, mech. robust electronic connectivity, and active shape morphing. The material is composed of a compliant and deformable liquid crystal elastomer (LCE) matrix that can achieve macroscopic shape change through a liquid crystal phase transition. The matrix is dispersed with liquid metal (LM) microparticles that are used to tailor the thermal and elec. conductivity of the LCE without detrimentally altering its mech. or shape-morphing properties. Demonstrations of this composite for sensing, actuation, circuitry, and soft robot locomotion suggest the potential for versatile, tissue-like multifunctionality.

Proceedings of the National Academy of Sciences of the United States of America published new progress about Actuators. 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

Ford, Michael J. published the artcileSize of liquid metal particles influences actuation properties of a liquid crystal elastomer composite, Category: alcohols-buliding-blocks, the main research area is metal particle actuation property liquid crystal elastomer composite.

Composites of liquid crystal elastomer (LCE) that are elec. conductive have the potential to function as soft “”artificial muscle”” actuators that can be reversibly stimulated with elec. Joule-heating. Conductivity can be achieved by embedding the LCE with droplets of an alloy of gallium and indium that is liquid at room temperature These soft artificial muscles are capable of >50% reversible actuation with an applied load. The key to actuation at high loadings of liquid metal (LM) is that the droplets deform with the surrounding matrix. By controlling the size of LM droplets through simple processing techniques, we show that the actuator properties of the LM-LCE muscle can be tuned. For example, composites with smaller liquid metal particles (ca. 10μm or less) are stiffer than those with larger liquid metal particles (ca. >100μm) and are capable of greater force output. However, smaller particles reduce actuation strain and composites with large particles exhibit significantly greater stroke length. Such tunability in actuation properties permits the fabrication of specialized soft artificial muscles, where processing of the composite controls actuation strain and actuation force.

Soft Matter published new progress about Actuators. 7575-23-7 belongs to class alcohols-buliding-blocks, name is Pentaerythritol tetra(3-mercaptopropionate), and the molecular formula is C17H28O8S4, Category: alcohols-buliding-blocks.

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Russo, C. published the artcileShape-memory actuators based on dual-curing thiol-acrylate-epoxy thermosets, HPLC of Formula: 7575-23-7, the main research area is thiol epoxy acrylate thermoset preparation actuator mech thermal property.

In this work, new shape-memory thermosets were developed using a thiol-acrylate-epoxy dual-curing system. A previously studied system has been successfully modified, introducing different amounts of tri(2,3-epoxypropyl)isocyanurate (ISO) and bisphenol A glycerolate (1 glycerol/phenol) diacrylate (BAGA) in order to enhance the thermomech. properties and the glass transition temperature of the final materials. Preliminary studies on the curing process proved that the curing process is not affected, and the critical ratio remains unchanged. Glass transition temperatures and thermomech. properties were successfully improved, extending the applicability of these thermosets to the field of soft-actuator. Shape-memory behavior was comprehensively investigated in unconstrained, fully and partially constrained conditions. Unconstrained experiment results showed excellent shape fixation and recovery, coupled with a fast recovery process. On the other hand, fully and partially constrained recovery experiments evidenced optimal performances obtained by the combination of both high crosslinking d. and high deformability in the programming stage. Considerably high values of recovery stress (up to 7 MPa) and work output (up to 1300 kJ/m3) were found confirming the high potentiality of these dual-cured thermosets in the field of soft-actuation.

eXPRESS Polymer Letters published new progress about Actuators. 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

Merkel, Daniel R. published the artcileMechanical energy dissipation in polydomain nematic liquid crystal elastomers in response to oscillating loading, Recommanded Product: Pentaerythritol tetra(3-mercaptopropionate), the main research area is nematic liquid crystal elastomer oscillating loading; polyester polythioether rubber nematic oscillating loading actuator.

Liquid crystal elastomers (LCEs) exhibit exotic mech. behaviors such as reversible actuation, elevated loss tangent above the glass transition, and soft elasticity; however, LCEs have yet to be thoroughly investigated under high-strain cyclic loading. This study explores a main-chain polydomain nematic elastomer synthesized from a thiol-acrylate Michael-addition reaction in the nematic state. Low-strain (i.e., <0.2%) dynamic mech. anal. and creep behavior was used to help link viscoelasticity and mesogen reorientation to high-strain cyclic loading. Specifically, the behavior was compared at discrete temperatures below the glass transition, in the nematic-rubbery regime, and in the isotropic-rubbery regime. Creep behavior in the nematic-rubbery regime was modeled using two characteristic relaxation times, which decreased with increasing temperature (τ1, τ2 (19 °C) = 140 s, 16 s, and τ1, τ2 (62 °C) = 2.4 s, 0.6 s). Samples were repeatedly loaded to 50 kPa at 5 cycles/min at each temperature for 350 cycles. In the rubbery nematic state at 62 °C, low threshold stress and short relaxation times allowed reversible domain reorientation between each cycle, resulting in a repeatable stress-strain curve with high hysteresis (220 kJ/m3). In contrast, the 19 °C and 39 °C conditions in the rubbery nematic state demonstrated ratcheting behavior in response to cyclic loading, which lowered the hysteresis values with increased cycling. The findings presented here represent the first investigation into mech. energy dissipation in main-chain nematic LCEs under large oscillating stress conditions. Overall, this study helps to better understand the role LCEs can play in energy dissipating applications with high values of strain and varying temperature Polymer published new progress about Actuators. 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