In high concentrations α‐methyl styrene is hepatotoxic and nephrotoxic in animals. Notre Service Clients et notre Service technique sont à votre service. Vapor density : 4.1 (vs air), Vapor density : 4.1 (vs air), Autoignition temperature : 1065°F, Contains 15 ppm p-tert-butylcatechol as inhibitor, Expl. CAS 98-83-9, EC Number 202-705-0, chemical formula C₆H₅C(CH₃)=CH₂. The correlation was usually expressed in terms of Hammett’s σ parameter and Brown’s σ+ parameter. The material is stabilised with 4-tert-Butylpyrocatechol. Table 10.1 shows the batch samples of living poly(α-methylstyrene) in tetrahydrofuran. 1 mg/m 3 ≙ 0.207 ml/m 3 (ppm) The MAK value for α‐methyl styrene of 100 ml/m 3 which was valid until 1997 was established in 1980 in analogy to the TLV value at the time. Biologically Active Compounds | Tous droits réservés. Relative rate constants assuming bimolecular reaction. xm0 is the mole fraction of initial monomer in solvent. - Find MSDS or SDS, a … Nous appliquons notre nouvelle marque à tous nos produits, Venez nous rendre visite et découvrir nos produits, Davantage de maîtrise & de flexibilité pour le développement & les procédés de fabrication de. Density : 0.90 g/mL at 25° C. For Research Use Only. RIADR : UN2303 / Classe : 3 / Packing group : III. Errera reported that diethyl acetonedicarboxylate condensed with triethyl orthoformate in hot acetic anhydride, and that treatment of the product with ammonia gave a poor yield of the pyrid-4-one (644) 〈1898CB1682〉. Based on the experimental data, it is possible to determine the values of the parameters used in the iGLE model. The temperature change also affects the solvent friction. 1.4 the plots of logkψ−logCHaq+−logaH2O are perfectly linear. The ratio of the barrier height over kBT is about 9 and kBT is in units of kJ/mol. inflammable, irritant, dangereux pour l'environnement, Déclaration Code IMDG (transport maritime). It appears that your browser has JavaScript disabled. Le champ quantité est vide. R. Faust, in Polymer Science: A Comprehensive Reference, 2012, The living polymerization of αMeSt was first achieved with the vinyl ether-HCl adduct/SnBr4-initiating system in CH2Cl2 at –78 °C.105 Controlled polymerization of αMeSt was obtained by the cumyl chloride/BCl3/–78 °C system in CH2Cl2/toluene 1/7 (v/v) solvent mixture in the presence of nBu4NCl.106 The living polymerization of αMeSt was also studied at –60 °C using iodine in liquid SO2/CH2Cl2 or liquid SO2/toluene.107 The living polymerization of αMeSt has also been established in hexanes/MeCl 60/40 (v/v) at –60 to –80 °C in the presence of DTBP using DPE-capped TMPCl with SnBr4 or SnCl441 and diphenyl alkyl chloride or HCl adduct of αMeSt dimer with BCl3 or SnCl4 coinitiators.108–110 Initiation with cumyl chloride, however, is slow relative to propagation, due to the absence of back strain. It is hoped that the same level of understanding of the propagation step will be reached in cationic systems. The critical effect is the irritation of the skin and mucous membranes. Reactivities and Gas Phase Basicities of p-Substituted (R) Styrenes. Toutes les références à Merck désignent Merck KGaA, Darmstadt, Allemagne. About Us | In hydration and bromination the relative reactivities are similar.221, 222 The much higher rate constant in the addition of benzhydryl cation to the E isomer than to the Z isomer may suggest the preliminary coordination of the carbenium ion with a phenyl substituent prior to the addition.223 In the Z isomer, the position of the methyl group on the same side as the phenyl group decreases the chance of this interaction. Transport : UN 2618, Class 3, Packing group III. In human lymphocytes in vitro, α‐methyl styrene induced a marginal increase (to less than twice the control value) in the incidence of SCE, which was found to be significant (p < 0.05) only at 0.33 mM (Norppa and Vainio 1983). As after long‐term studies with various species including rhesus monkeys the NOAEL for systemic toxicity was found to be 200 ml/m3, the provisional retention of the MAK value of 100 ml/m3 is justified. Even 26 appears to have only a very small effect, the one point available giving a value of 1.3. Soyez plus que sûr(e) ! The squares are experimental data and the solid curve is our theoretical model. The equilibrium monomer concentration is reached in a relatively short amount of time and the extent of polymerization is 75%. The kinetics of polymerization near the polymerization line of poly(α-methylstyrene) in the solvent tetrahydrofuran (THF) is initiated by sodium naphthalide or cesium naphthalide. In Fig. The polymerization of α-methylstyrene has been experimentally studied by Greer and coworkers [79]. Ethyl acetoacetate is reported to condense with aromatic aldehydes and ammonium acetate in acetic acid to give piperid-4-one-3-carboxylates (648), although formaldehyde gave the normal Hantzsch product 〈54JIC832〉. Un transfert rapide et sûr des boîtes de gélose vers l'isolateur. Density : 0.909 g/mL at 25°C (lit.). Personal Protective Equipment: Eyeshields;Gloves;type N95 (US);type P1 (EN143) respirator filter RIDADR: NONH for all modes of transport: WGK Germany: 3 Synonyms. Greer has studied the extent of polymerization as a function of temperature for living poly(α-methylstyrene) in THF initiated by sodium naphthalide with mole fraction of monomers xm0=0.15378, and the mole ratio of initiators to monomers r=0.0044. In the following text, we call the first set of data (Te=267K) sample 1, and the second set of data (Te=271K) sample 2 as shown in Table 10.1. 124(14) , 144316, (2006). CAS 1319-73-9, EC Number 215-292-7, chemical formula 3/4-(CH₃)C₆H₄CH=CH₂. Figure 1.5. Studies of dermal irritation with rabbits yielded no evidence of the absorption of toxic amounts of α‐methyl styrene via the skin (Wolf et al. The LD50 in rats was given as 4900 mg/kg body weight (Wolf et al. CAS 1319-73-9, EC Number 215-292-7, chemical formula 3/4-(CH₃)C₆H₄CH=CH₂. While volunteers found concentrations of 200 ml/m3 still to be unpleasant, 100 ml/m3 was tolerated without great discomfort. In man, irritation of the eyes was observed from concentrations of about 200 ml/m3. Polymerization of styrene by sulfuric acid was one of the first examples of polymer formation through cationic polymerization50 but was not much studied later on. Excess acidity plots for the hydrations of 1-methylcyclopentene and 1-methylcyclohexene in aqueous H2SO4 at 25 °C. Georges Sauvet, Pierre Sigwalt, in Comprehensive Polymer Science and Supplements, 1989. The esters would be inactive, but might be reactivated by addition of a weaker acid in high concentration. Nous sommes votre partenaire privilégié pour les systèmes et services de purification d'eau. Anticorps primaires et secondaires, bloqueurs et services à façon. The reference temperature, for which kBT0=1kJ/mol, is 120 K. With this assignment, numerical simulations of the iGLE can be compared to the behavior of corresponding physical systems with specified units. Sigma-Aldrich offers a number of 4-Methylstyrene products. SMILES : CC1=CC=C(C=C1)C=C. Methylstyrene (mixture of 3- and 4-isomers) stabilised with 4-tert-butylpyrocatechol for synthesis. There are no data available for short‐term inhalation exposure to α‐methyl styrene. The living polymerization of p-chloro-αMeSt (pClαMeSt) was achieved using the 1,3-dimethyl-1,3-diphenyl-1-chlorobutane/BCl3-initiating system in MeChx/MeCl 60/40 (v/v) at –80 °C.111, Yanping Qin, ... Rigoberto Hernandez, in Annual Reports in Computational Chemistry, 2008. The rate constants are obtained using the simple kinetic model of [79]. Nous appliquons notre nouvelle marque à tous nos produits, Venez nous rendre visite et découvrir nos produits, Davantage de maîtrise & de flexibilité pour le développement & les procédés de fabrication de. In the only example of this type of synthesis a number of α-methylstyrenes react with formaldehyde and ammonia (or a primary amine) to give 1,2,5,6-tetrahydropyridines (642) 〈56JA425; 56JOC1194, 56JOC1195〉. Des questions techniques ? Density: 1.07 g/mL at 25 °C: Molecular Formula: C 17 H 18: Molecular Weight: 222.32482: Water Solubility: hydrocarbons, esters and ketones: soluble Safety Information . Polymerizations were rapid at 25 °C in (CH2Cl)2 and led (in 10 to 20 min) to limited yields (for H2SO4 ≤ 4 × 10−3 M) that could reach 100% for higher H2SO4 concentration. Please check your email for instructions on resetting your password. Find the products and services for your process. The fraction of monomer remaining as a function of time for poly(α-methylstyrene) in THF initiated by sodium naphthalide is shown in Figure 10.2. Catégories. MFCD00284291 Top Suppliers: I want be here. Poly(α-methylstyrene) is a fully flexible linear polymer chain joined by covalent bonds. mp = −24°C (lit.) Journals | and you may need to create a new Wiley Online Library account. A NOAEL (no observed adverse effect level) of 200 ml/m3 was determined for all species investigated (Wolf et al. Compound 26 has been studied at several temperatures in aqueous perchloric acid, with one measurement in DClO4;134 27 at 25 °C in both aqueous H2SO4 and aqueous HClO4, plus measurements in the deuterated media;135 and the methyl derivatives 28 and 29 at 25 °C in aqueous H2SO4, with one measurement each in D2SO4.135 The results are presented graphically in Figs 1.4 and 1.5.

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