Tag: 200-300

Dependence of Thermal Stability on Molecular Structure of RAFT/MADIX Agents: A Kinetic and Mechanistic Study was written by Zhou, Yanwu;He, Junpo;Li, Changxi;Hong, Linxiang;Yang, Yuliang. And the article was included in Macromolecules (Washington, DC, United States) in 2011.Recommanded Product: Benzyl benzodithioate This article mentions the following:

The thermal decomposition of different classes of RAFT/MADIX agents, namely dithioesters, trithiocarbonates, xanthates, and dithiocarbamates, were studied through heating in solution The decomposition behavior is complicated interplay of the effects of stabilizing Z-group and leaving R-group. The mechanism of the decomposition is mainly through three pathways, i.e., β-elimination, α-elimination, and homolysis of dithiocarbamate (particularly for universal RAFT agent). The most important pathway is the β-elimination of thiocarbonylthio compounds possessing β-hydrogen, leading to the formation unsaturated species. For the leaving group containing solely α-hydrogen, such as benzyl, α-elimination takes place, resulting in the formation of (E)-stilbene through a carbene intermediate. Homolysis occurs specifically in the case of a universal RAFT agent, in which a thiocarbonyl radical and an alkylthio radical are generated, finally forming thiolactone through a radical process. The stabilities of the RAFT/MADIX agents are studied by measuring the apparent kinetics and activation energy of the thermal decomposition reactions. Both Z-group and R-group influence the stability of the agents through electronic and steric effects. Lone pair electron donating heteroatoms of Z-group show a remarkable stabilizing effect while electron withdrawing substituents, either in Z- or R-group, tends to destabilize the agent. In addition, bulkier or more β-hydrogens result in faster decomposition rate or lower decomposition temperature Thus, the stability of the RAFT/MAIDX agents decreases in the order where R is (with identical Z = phenyl) -CH₂Ph (5) >-PS (PS-RAFT 15) > -C(Me)HPh (2) >-C(Me)₂C(=O)OC₂H₅ (7) >-C(Me)₂Ph(1) > -PMMA (PMMA-RAFT 16) > -C(Me)₂CN (6). For those possessing identical leaving group such as 1-phenylethyl, the stability decreases in the order of O-Et (11) > -N(CH₂CH₃)₂ (13) > -SCH(CH₃)Ph (8) > -Ph (2) > -CH₂Ph (4) > -PhNO₂ (3). These results consort with the chain transfer activities measured by the CSIRO group and agree well with the ab initio theor. results by Coote. In addition, the difference between thermal stabilities of the universal RAFT agents at neutral and protonated states was demonstrated. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Recommanded Product: Benzyl benzodithioate).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Recommanded Product: Benzyl benzodithioate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Thermotropic phase behavior of model membranes composed of phosphatidylcholines containing methyl iso-branched fatty acids. 1. Differential scanning calorimetric studies was written by Lewis, Ruthven N. A. H.;McElhaney, Ronald N.. And the article was included in Biochemistry in 1985.Reference of 3903-40-0 This article mentions the following:

The thermotropic phase behavior of aqueous dispersions of phosphatidylcholines (PCs) containing 1 of a series of Me iso-branched fatty acyl chains was studied by differential scanning calorimetry. These compounds exhibited a complex phase behavior on heating which included 2 endothermic events, a gel/gel transition, involving a mol. packing rearrangement between 2 gel-state forms, and a gel/liquid-crystalline phase transition, involving the melting of the hydrocarbon chains. The gel/liquid-crystalline transition was a relatively fast, highly cooperative process which exhibited a lower transition temperature and enthalpy than did the chain-melting transitions of saturated straight-chain PCs of similar acyl chain length. In addition, the gel/liquid-crystalline phase transition temperature was relatively insensitive to the composition of the aqueous phase. In contrast, the gel/gel transition is a slow process of lower cooperativity than the gel-liquid-crystalline phase transition and is sensitive to the composition of the bulk aqueous phase. The gel/gel transitions of the Me iso-branched PCs had very different thermodn. properties and depended in a different way on hydrocarbon chain length than did either the subtransitions or the pretransitions observed with linear saturated PCs. The gel/gel and gel/liquid-crystalline transitions were apparently concomitant for the shorter-chain iso-branched PCs, but diverged on the temperature scale with increasing chain length, with a pronounced odd/even alternation of the characteristic temperatures of the gel/gel transition. The observations were be rationalized by assuming that the stable conformation characteristic of these lipids at temperatures below the gel/gel transition temperature and their conformation in the liquid-crystalline state are such that direct interconversions between the 2 states is improbable and that such interconversions must proceed via an intermediate state or states. In the experiment, the researchers used many compounds, for example, 12-Methoxy-12-oxododecanoic acid (cas: 3903-40-0Reference of 3903-40-0).

12-Methoxy-12-oxododecanoic acid (cas: 3903-40-0) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Reference of 3903-40-0

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Optimization of a new polymeric chromium (III) membrane electrode based on methyl violet by using experimental design was written by Kazemi, Sayed Yahya;Hamidi, Akram sadat;Asanjarani, Neda;Zolgharnein, Javad. And the article was included in Talanta in 2010.Application In Synthesis of Dimethyl decanedioate This article mentions the following:

Placket-Burman and Box-Behnken designs were applied as exptl. design strategies to screen and optimize the influence of membrane ingredients on the electrode performance. A new poly(vinyl chloride) membrane sensor for Cr(III) based on Methyl violet as an ionophore was planned. The major variables to find a model for achieving the best Nernstian slope as response were: PVC, plasticizers, Methyl violet, KpClTPB, pH, conditioning time and internal solution concentration Placket-Burman design was used to screen the main factors and Box-Behnken response surface was led to find a model for optimizing the response. The optimized membrane electrode shows a Nernstian slope for chromium (III) ions over a wide linear range from 1.99 × 10^-6 to 3.16 × 10^-2 mol L^-1 and a slope of 19.5 ± 0.1 mV decade^-1 of activity. It would be successfully applied in the pH range from 3.5 to 6.5 with detection limit of 1.77 × 10^-6 mol L^-1 (0.092 mg L^-1). The response time of the sensor is ∼8 s and the membrane can be used for >6 wk without any deviation. The relative standard deviations (relative standard deviation) for six replicate the measurements of 1.0 × 10^-4 and 1.0 × 10^-3 mol L^-1 of Cr(III) were 3.2 and 3%, resp. The electrode revealed comparatively good selectivity with respect to many cations including alkali earth, transition and heavy metal ions. The electrode was successfully used as an indicator in the potentiometric titration of Cr(III) with EDTA and was also applied to the direct determination chromium (III) content of spiked water and soil samples. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6Application In Synthesis of Dimethyl decanedioate).

Dimethyl decanedioate (cas: 106-79-6) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Application In Synthesis of Dimethyl decanedioate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

RAFT grafting polymerization of styrene on the surface of SiO₂ was written by Li, De-ling;Wang, Wei;Li, Ping;Wang, Dong-chao. And the article was included in Gongneng Gaofenzi Xuebao in 2012.Related Products of 27249-90-7 This article mentions the following:

Double bonds were immobilized onto nano-SiO₂ via hydrolyzing alkoxysilane moiety of γ-methacryl trimethoxysilane for condensation with hydroxide groups from nano-SiO₂. RAFT grafting polymerization of styrene from nano-SiO₂ was carried out from the immobilized double bonds, in which azobisisobutyronitrile was used as initiator, 2-cyanoprop-2-yl dithiobenzoate, benzyl dithiobenzoate, benzyl dithiopivalate, 1,2,4-triazolyl-1-carbodithioic acid benzyl ester were used as RAFT agent, resp. Results showed that RAFT grafting polymerization rate of styrene from SiO₂ was decided by Z group of RAFT agent. Grafting polymerization of styrene from SiO₂ mediated by benzyl dithiopivalate exhibited the highest grafting polymerization rate. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Related Products of 27249-90-7).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Related Products of 27249-90-7

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Phosphine-mediated domino reactions of phthalimidomalonates with allenoates or but-2-ynoate: facile entry into highly functionalized pyrroloisoindolinone derivatives was written by Huang, Zhusheng;Chen, Qingqing;Yang, Xiuqin;Liu, Yang;Zhang, Li;Lu, Tao;Zhou, Qingfa. And the article was included in Organic Chemistry Frontiers in 2017.Related Products of 1190-39-2 This article mentions the following:

A phosphine-mediated domino reaction between phthalimidomalonates and allenoates furnishes highly functionalized pyrroloisoindolinone derivatives, e.g., I, in synthetically useful yields. When Et but-2-ynoate was reacted with phthalimidomalonates under the same conditions, pyrroloisoindolinone derivatives were also obtained in good to excellent yields. The mechanism for the transformation is a tandem γ-umpolung/Wittig/γ-umpolung process. The present domino reaction not only exploits the potential of allenoates, but also extends the existing phosphine-mediated cyclization scope. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Related Products of 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Related Products of 1190-39-2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Hybrid nanocomposites of a fluorescent block copolymer and quantum dots: An efficient way for energy transfer was written by Moura, I.;de Sa, A.;Abreu, Ana S.;Oliveira, M.;Machado, A. V.. And the article was included in Dyes and Pigments in 2017.Safety of Benzyl benzodithioate This article mentions the following:

Forster resonance energy transfer (FRET) phenomenon has great potential in several applications, whose efficiency is dependent on the energy transfer between a suitable pair of fluorophores. In this work, a new block copolymer, PS-b-PS(co-pyren-1-yl), with fluorescent properties, was synthesized and used as donor component in the fluorophores pair copolymer/cadmium telluride quantum dots (CdTe QDs). Thus, water-soluble CdTe QDs, previously transferred into organic phase, by replacing the stabilizer ligands, thioglycolic acid by 1-dodecanethiol (1-DDT), were used to prepare a new hybrid nanocomposite. FRET studies between the fluorescent copolymer and CdTe-DDT QDs revealed that this fluorophores pair can experience FRET with an efficiency of 48%, being an efficient antenna system for light harvesting applications. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Safety of Benzyl benzodithioate).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Safety of Benzyl benzodithioate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Synthesis, film-forming properties, and thermal and light sensitivity of N,N’-bis[4-hydroxy(alkoxy, acyloxy)-3-alkoxyphenylmethylidene]benzene-1,4-diamines was written by Dikusar, E. A.;Kozlov, N. G.;Potkin, V. I.;Azarko, V. A.;Yuvchenko, A. P.. And the article was included in Russian Journal of General Chemistry in 2008.Quality Control of 4-Formyl-2-methoxyphenyl isobutyrate This article mentions the following:

Previously unknown E,E-isomeric Schiff bases were synthesized by reaction of p-phenylenediamine with 4-hydroxy-3-methoxybenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, and their O-alkyl and O-acyl derivatives in anhydrous methanol. Film-forming properties and thermal and light sensitivity of the products were studied. In the experiment, the researchers used many compounds, for example, 4-Formyl-2-methoxyphenyl isobutyrate (cas: 20665-85-4Quality Control of 4-Formyl-2-methoxyphenyl isobutyrate).

4-Formyl-2-methoxyphenyl isobutyrate (cas: 20665-85-4) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Quality Control of 4-Formyl-2-methoxyphenyl isobutyrate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Ruthenium-catalyzed stereospecific benzylic alkylation of optically active benzyl esters with malonate nucleophiles was written by Tsuji, Hiroaki;Suzuki, Koki;Kawatsura, Motoi. And the article was included in Tetrahedron Letters in 2021.Name: Diethyl isobutylmalonate This article mentions the following:

Herein, the study for the ruthenium-catalyzed benzylic alkylation of chiral benzyl esters with malonates as a carbon nucleophile was described. A combination of [Cp*RuCl₂]₂ and picolinic acid found to be effective for the title reaction, provided the chiral benzylic alkylation products with retention of stereochem. of the starting material. The ruthenium catalysis was proceed via a double inversion mechanism was proposed. In the experiment, the researchers used many compounds, for example, Diethyl isobutylmalonate (cas: 10203-58-4Name: Diethyl isobutylmalonate).

Diethyl isobutylmalonate (cas: 10203-58-4) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Name: Diethyl isobutylmalonate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Synthesis and characterization of poly(ester amide amide)s of different alkylene chain lengths was written by Girard, Clement;Gupta, Manisha;Lallam, Abdelaziz;Anokhin, Denis V.;Bovsunovskaya, Polina V.;Akhyamova, Azaliya F.;Melnikov, Alexey P.;Piryazev, Alexey A.;Rodygin, Alexander I.;Rychkov, Andrey A.;Grafskaya, Kseniia N.;Shabratova, Ekaterina D.;Zhu, Xiaomin;Moller, Martin;Ivanov, Dimitri A.. And the article was included in Polymer Bulletin (Heidelberg, Germany) in 2019.Safety of Dimethyl decanedioate This article mentions the following:

In this work, a series of aliphatic biodegradable poly(ester amide amide) polymers was synthesized by melt polycondensation of a tailor-made amide-containing monomer based on 1,4-diaminobutane and ε-caprolactone and different dicarboxylic acid Me esters with even number of methylene groups. The synthesized polymers were characterized by ¹H NMR, FT-IR spectroscopy, GPC, SAXS and WAXS. DSC results show that the m.p. is located at about 150 °C for all polymers. X-ray scattering experiments in small and wide angles reveal formation of crystals with extended-chain conformation resulting in strict periodicity of electron d. along the main chain. TGA data indicate the high thermal stability of polymers to temperatures above 350 °C, which are much above the m.p. The obtained characteristics of the newly synthesized PEAAs can open new perspectives for melt processing to fabricate films, highly oriented fibers and injection-molded parts with good thermal stability and mech. performance. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6Safety of Dimethyl decanedioate).

Dimethyl decanedioate (cas: 106-79-6) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Safety of Dimethyl decanedioate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Long-Chain Modification of the Tips and Inner Walls of MWCNTs and Their Nanocomposite Reverse Osmosis Membranes was written by Li, Qing;Yang, Dengfeng;Liu, Qingzhi;Wang, Jianhua;Ma, Zhun;Xu, Dongmei;Gao, Jun. And the article was included in Membranes (Basel, Switzerland) in 2022.Product Details of 3903-40-0 This article mentions the following:

Multi-walled carbon nanotubes (MWCNTs) were modified on the tips and inner walls by 12-chloro-12-oxododecanedioic acid-Me ester groups and then added to the polyamide composite membranes to prepare MWCNT-CH₂OCOC₁₂H₂₃O₂ membranes for desalination. The characterization results of transmission electron microscopy, Fourier transform, IR transform, and thermogravimetric anal. showed that the 12-chloro-12-oxododecanedioic acid-Me ester group was successfully grafted to the entrances and inner walls of the MWCNTs. The performance of the MWCNTs’ composite membranes was evaluated by SEM, contact angle, and filtration test. The modified membrane morphol. is more uniform, and there is no structural damage. The grafting of carbon nanotubes with Me 12-chloro-12-oxydodecyldicarboxylate could improve the hydrophilicity of the membrane. Under identical conditions, the water flux of MWCNT-CH₂OCOC₁₂H₂₃O₂ membranes was higher than that of the pristine carbon nanotube’s membrane, and the desalination rate was also slightly improved. In the experiment, the researchers used many compounds, for example, 12-Methoxy-12-oxododecanoic acid (cas: 3903-40-0Product Details of 3903-40-0).

12-Methoxy-12-oxododecanoic acid (cas: 3903-40-0) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Product Details of 3903-40-0

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics