Methyl Allyl Alcohol Research Articles

Synthesis, Characterization and Evaluation of a Novel Tetraphenolic Compound as a Potential Antioxidant.

A novel antioxidant containing four hydroxyl groups, namely 2,2'-(2-methylpropane-1,3-diyl)bis(hydroquinone) (MPBHQ), was synthesized using hydroquinone and methylallyl alcohol as the raw materials, phosphoric acid as the catalyst, and toluene as the solvent system. The structure of MPBHQ was characterized by mass spectrometry, nuclear magnetic resonance, ultraviolet spectroscopy, and infrared spectroscopy. The results showed that MPBHQ has a good radical scavenging effect, as measured by the ORAC assay, DPPH radical scavenging assay, ABST radical scavenging assay, and Rancimat test. In fatty acid methyl ester and lard without exogenous antioxidants, MPBHQ showed better antioxidant performance than butylated hydroxytoluene (BHT), hydroquinone (HQ), tert-butyl hydroquinone (TBHQ), and propyl gallate (PG), meeting the need for a new antioxidant with better properties to ensure the oxidative stability of lipids and biodiesel.

Temperature-sensitive amphiphilic nanohybrid as rheological modifier of water-in-oil emulsion drilling fluid: Preparation and performance analysis

In our previous study, as a rheological modifier for flat rheology water-based drilling fluid, binary composite temperature-sensitive SiO2 nanohybrid was successfully synthesized and characterized [J. Petrol. Sci. Eng. 219 (2022), 111,096]. The aim of this study was to investigate the flat rheological characteristics of emulsion drilling fluid, a temperature-sensitive amphiphilic ternary composite nanohybrid was prepared via the copolymerization of temperature sensitive polymer monomers N-isopropylacrylamide (NIPAM) and methylallyl alcohol (MAA) in the presence of nano-silica surface-capped by modifier containing double bond (denoted as SiO2-D). The as-prepared PNM/SiO2-D (PNM refers to polymerized NIPAM and MAA) nanohybrid was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy and transmission electron microscopy. Findings indicate that PNM/SiO2-D nanohybrid has a three-dimensional network structure and a particle size of 20–30 nm. Rheological properties of PNM/SiO2-D nanohybrid in aqueous solution, water-in-oil (W/O) emulsion system and W/O emulsion drilling fluid system were investigated, respectively. And the results revealed that PNM/SiO2-D nanohybrid as a rheological modifier is more sensitive to temperature in the emulsion with a high water-oil ratio, and significantly increase the viscosity of the emulsion system at elevated temperatures. Furthermore, the W/O emulsion drilling fluid with a water-oil ratio of 4:6 exhibits higher modulus values than the one with a water-ratio of 1:9, due to the better suspending capacity of the former for drill cuttings under static conditions, which could ensure the application of emulsion drilling fluid in drilling process.

Structure and Vibrational Spectroscopy of 2-Methylallyl Alcohol

Structure and Vibrational Spectroscopy of 2-Methylallyl Alcohol

A novel anti-clay silane-modified polycarboxylate superplasticizer: Preparation, performance and mechanism

This article proposes a low-temperature free radical polymerization method of anti-clay silane-modified polycarboxylic superplasticizer (S-PCE). Through molecular structure design, strong adsorption silane coupling agent (γ-methylacrylloxy propyl trimethoxysilane, KH570) was introduced in S-PCE. A series of tests and theoretical studies were carried out to obtain chemical structure characterization, dispersion ability, montmorillonite (MMT) tolerance and adsorption behavior of S-PCE. The results showed that compared with the traditional methylallyl alcohol polyoxyethylene ether (HPEG) type PCE (H-PCE) and low clay-sensitivity Naphthalene-based superplasticizer (BNS), S-PCE possessed better dispersion and fluidity retention ability of cement particles in clay-involved environment, and could appropriately improve mechanical properties of concrete. It is mainly due to that silanol (Si-OH) groups can be dehydrated and bonded to silanol on the surface of cement particles and MMT. Thus, the competitive adsorption advantage of MMT was lowered, the possibility of S-PCE binding with cement particle was greatly improved and the intercalation of polyoxyethylene side chain was avoided.

Mechanistic and kinetics study on the reaction of methylallyl alcohol with Cl: A theoretical study

The Cl-initiated degradation mechanism of methylallyl alcohol (MA) has been investigated by performing quantum chemical calculations. The reactants, transition states, intermediates and products are optimized at the MP2/6-311G(d,p) level. A detailed degradation mechanism is presented and discussed in this paper. The possible reactions of MA include two Cl-addition channels and eight H-abstraction reactions. Present results show that Cl-addition reactions are more favorable than H-abstraction processes, and the most energetically favorable pathway is the Cl-addition to the terminal carbon C1 atom. Main products detected in experiments and obtained in our study have been determined. The rate constants of dominant paths over a temperature range of 180–380 K are estimated. The total rate coefficients show a negative temperature dependence, and the Arrhenius equation is fitted as ktotal = (1.81 × 10−11)exp(511.21/T). At 298 K, the atmospheric lifetime of MA with respect to Cl is estimated to be 1.11 days.

Structure and properties of polycarboxylic acid dispersants synthesized by RAFT method

Polycarboxylic acid dispersants (PCs) with comb‐like molecular structure have become the focus of dispersants. However, there are many contradictions in the study of molecular structure of polycarboxylic acids. In this article, a series of PCs with different molecular structures were prepared from acrylic acid (AA) and methyl allyl alcohol polyoxyethylene ether (TPEG) by reversible addition fragmentation chain transfer (RAFT) polymerization. The structural characteristics of PCs were characterized by flourier transform infrared spectrometer (FT‐IR), 1H nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The dispersion performance of PCs to cement was measured by the fluidity and adsorbing capacity. The results show that the dispersion performance and adsorbing capacity of PCs are significantly related to its structure. The adsorption and dispersion properties increase with the increase of carboxyl content and molecular weight. However, this phenomenon is limited to a certain range that the acid ether ratio in this range is no greater than 5:1, and the molecular weight is no greater than PC‐4 (Mw = 82 125, Mn = 63 889).

Preparation of Isocyanate Terminated Polysiloxane and Its Application in Crease Resistant Finishing of Silk Fabric

In order to improve the crease resistant property of silk fabric and reduce the tensile strength damage of finished silk fabric, the isocyanate terminated polysiloxane (ITPSI) was prepared with hydrogen terminated polysiloxane (HTPSI) and methylallyl alcohol as raw materials, diphenylmethane diisocyanate (MDI) as functional modifier, and it was used as crease resistant finishing agent for silk fabric. The effect factors of crease resistant properties of finished silk fabric were studied and the crease resistant properties of finished silk fabric were evaluated. The results showed that when the molar mass of HTPSI was 1914 g/mol, the finished silk fabric obtained the best crease resistant property. The optimal conditions of the finishing process was that the dosage of ITPSI crease resistant finishing agent was 60 g/l, the baking temperature was 150 °C, and the baking time was 3 min. Under these finishing conditions, the dry/wet crease recovery angles (DCRA/WCRA) of finished silk fabric were 302.6 ° and 229 °, respectively, both the crease resistant property and the washability were good. There is no apparent effects on tensile strength and whitenesss of finished silk fabric by this treatment. Compared with epoxy modified polysiloxane (EMPSI) crease resistant finishing agent on the market, the silk fabric finished by ITPSI crease resistant finishing agent had better crease resistant effect and less tensile strength damage.

NMR study on bleeding properties of the fresh cement pastes mixed with polycarboxylate (PCE) superplasticizers

This study investigated the bleeding properties of fresh cement paste mixed with various polycarboxylate superplasticizers (PCEs) using low-field nuclear magnetic resonance (NMR). The PCE superplasticizers were synthesized with various acid to ether ratio, molecule weight of methyl allyl alcohol polyoxyethylene ether (HPEG) and functional groups. The bleeding process of fresh cement paste mixed with the PCE superplasticizers was monitored by low-field NMR and the bleeding rate was obtained with the calculation of transverse relaxation time (T2) peaks. Results showed that the proposed NMR method can not only evaluate the bleeding extent, probe the microstructure of fresh cement paste but also provide information about the PCEs concentration of bleeding water. It was found that PCE superplasticizers synthesized with high acid to ether ratio would reduce the bleeding, and PCE superplasticizers synthesized with the HPEG of molecule weight 4400 and functional group of methyl methacrylate (MMA) would lead to less bleeding when the fresh cement paste reached the same fluidity. The T2 relaxation time of bleeding water increased with bleeding rate, which implies the PCEs molecules in bleeding water was diluted during the bleeding process. Furthermore, the results suggest more bleeding water coming out from the pore water results in larger microstructure changes due to sedimentation.

UV-curable waterborne epoxy acrylate coating modified by monomethacryloyloxy-terminated fluorinated oligomer

Monomethacryloyloxy-terminated fluorinated oligomers (PPFOMA-GMA and PHFBMA-GMA) and methyl allyl alcohol polyoxyethylene ether-modified epoxy resin (HPEGEA) were successfully synthesized and used as reactive additives and emulsifier for epoxy acrylate, respectively. FTIR, 1H NMR, and GPC were used to characterize the structures of PPFOMA-GMA, PHFBMA-GMA, and HPEGEA. The influence of the concentrations of PPFOMA-GMA and PHFBMA-GMA on the properties of waterborne epoxy acrylate (WEA) resin coatings was investigated. The surface energy of waterborne epoxy acrylate coating was decreased from 38.20 mN/m to 15.31 mN/m by adding just 0.21 wt% PPFOMA-GMA, indicating its high effectiveness in improving the hydrophobic properties of the surface. The surface compositions of the WEA resin coatings (with 0.85 wt% PPFOMA-GMA or 0.85 wt% PHFBMA-GMA) were characterized by XPS. The XPS results confirmed the quantitative enrichment of fluorine atoms on the surface. What is more, the physical properties of waterborne epoxy acrylate coatings prepared with different concentrations of fluorinated reactive additive, such as optical transmittance, adhesion (on glass, PET, and tinplate), pencil hardness, water absorption, and thermal properties, were also analyzed in detail. Hence, the waterborne epoxy acrylate coatings prepared with low concentrations of reactive additives were economical and have potential for large-scale industrial applications.

Preparation and evaluation of polyampholyte inhibitor DAM

In this study, polyampholyte inhibitor DAM was synthesized from three monomers, namely, diallyl dimethyl ammonium chloride, methyl allyl alcohol and 2-acrylamido-2-methyl propane sulfonic acid, by aqueous solution polymerization.

Continuous Catalytic Production of Methyl Acrylates from Unsaturated Alcohols by Gold: The Strong Effect of C═C Unsaturation on Reaction Selectivity

Here we demonstrate the gas-phase catalytic production of methyl acrylates by oxygen-assisted coupling of methanol with the unsaturated alcohols allyl alcohol and methylallyl alcohol over nanoporous gold (npAu) at atmospheric pressure. Analogous investigations on O-activated Au(110) exhibit the same pattern of reactivity and are used to establish that the competition between methoxy and allyloxy (or methallyloxy) reaction intermediates for adsorption sites, mediated by the reactants themselves, determines the selectivity of reaction. Our results clearly show that the C═C bond substantially increases the binding efficacy of the allyloxy (or methallyloxy), thus requiring extremely high methanol mole fractions (>0.99) in order to achieve comparable surface concentrations of methoxy and produce optimum yields of either methacrylate or methyl methacrylate. Allyloxy and methallyloxy were favored by factors of ∼100 and ∼450, respectively, vs methoxy. These values are more than 1 order of magnitude greater than those measured for competitive binding of ethoxy and 1-butoxy vs methoxy, demonstrating the strong effect of the carbon–carbon bond unsaturation. The 4.5-fold increase due to the addition of the methyl group in methylallyl alcohol vs allyl alcohol indicates the significant effect of the additional van der Waals interactions between the methyl group and the surface. Gas-phase acidity is also shown to be a good qualitative indicator for the relative binding strength of the alkoxides. This work provides insight into the control of reaction selectivity for coupling reactions and demonstrates the value of fundamental studies on single crystals for establishing key principles governing reaction selectivity. Notably, these oxygen-assisted coupling reactions occur without oxidation of the C═C bond.

HPLC with polysaccharide chiral stationary phase in polar‐organic phase mode: Application to the asymmetric epoxidation of allylic alcohols

A simple and rapid HPLC method using a polysaccharide-based chiral stationary phase (Chiralpak AD-H) in polar-organic phase mode has been developed for direct resolution of glycidyl nitrobenzoate (GNB) and 2-methyl glycidyl nitrobenzoate (MGNB) enantiomers. ACN and methanol were used as mobile phase and the effects of the addition of ethanol and 2-propanol as organic modifier in the mobile phase, flow rate and the column temperature were tested. The optimized conditions were: methanol/ethanol (80:20) at a flow rate of 0.9 mL/min and 40 degrees C. Analysis time was < or = 13 min and the chiral resolution was > or = 2. The method was validated and resulted to be selective, precise and accurate. The method was found to be linear in 2-300 microg/mL range (R(2) >0.999) with an LOD nearly 0.5 microg/mL for four enantiomers. GNB and MGNB enantiomers were obtained by asymmetric epoxidation of allyl alcohol and 2-methyl allyl alcohol, respectively, using chiral titanium-tartrate complexes as catalyst and dichloromethane as solvent after in situ derivatization of the intermediate glycidols derivatives. The quite simple and rapid validated method was applied successfully for direct determination of the enantiomeric excess (> or = 90%) and yield obtained in real samples of asymmetric epoxidation of allylic alcohols without further purification, workup or solvent removal. The method provides a useful and value-added tool for controlling the enantiomeric purity of the synthesized epoxides.

EPR studies of the formation and transformation of isomeric radicals [C3H5O]˙. Rearrangement of the allyloxyl radical in non-aqueous solution involving a formal 1,2-hydrogen-atom shift promoted by alcohols

At 220 K in cyclopropane solvent, hydrogen-atom abstraction from allyl alcohol by ButO˙, EtO˙, PhMe2CO˙, (Me3Si)2N˙ or triplet-state acetone gives the 1-hydroxyallyl radical 3 as a ca. 3 : 1 mixture of the syn- and anti-isomers. In contrast, the allyloxyl radical does not react with allyl alcohol to bring about abstraction of hydrogen, but instead undergoes a more rapid alcohol-promoted rearrangement to give 3 as a ca. 1 : 1 mixture of the syn- and anti-forms. 2-Methylallyl alcohol, ethanol and propan-2-ol also induce this formal 1,2-H-atom shift in the allyloxyl radical. In the presence of ethan[2H]ol, both 3 and (3-OD) are formed and as [EtOD] is increased from 0.3 to 3.6 mol dm–3[3-OD]/[3] first passes through a maximum value of ca. 1 and then decreases to 0.38. It is proposed that there is more than one mechanism for the alcohol-induced rearrangement of the allyloxyl radical, one that involves assisted migration of hydrogen from the α-carbon atom to the oxygen atom and another that results in incorporation of deuterium from the EtOD. The importance of the latter mechanism decreases at high alcohol concentrations and this behaviour is thought to be related to the extent of association of the alcohol by hydrogen-bonding. The allyloxyl radical was generated by UV photolysis of allyl tert-butyl peroxide and by ring opening of the oxiranylmethyl radical, derived from epibromohydrin or epichlorohydrin by halogen-atom abstraction. Ab initio molecular orbital calculations predict that an unassisted 1,2-H-atom shift in the allyloxyl radical will involve a very large activation energy. The alcohol is believed to serve a dual function in promoting the rearrangement: first, to increase the acidity of the α-CH2 group by hydrogen-bonding to the oxygen atom of the allyloxyl radical and, secondly, to provide a basic oxygen atom to facilitate the transfer/removal of a erotic α-hydrogen atom.

Conversion of methylallyl alcohol into C2-methyl-1,2-di- O-hexadecylglycerophosphocholine, a conformationally restricted phospholipid

The synthesis of C2-methyl-1,2-di- O-Hexadecylglycerophosphocholine from methylallyl alcohol is described and the 13C-NMR assignments of all glycerol backbone and headgroup resonances are provided. Bond rotations in the glycerol backbone of this diether phospholipid derivative are impeded by steric hindrance exerted by the methyl group. We discuss the utility of this conformationally restricted C2-alkyl phospholipid analog for study of the influence of conformational changes at the lipid-water interface of bilayers on the interactions between lipids and other membrane components.

Conformational equilibrium and internal hydrogen bonding in 2-methylallyl alcohol: Detection of a second conformer by microwave spectroscopy on the basis of ab initio structure calculations

On the basis of 4-21G ab initio geometry refinements the microwave spectrum of a second conformer of 2-methylallyl alcohol, CH 2C(CH 3)CH 2OH, has been assigned. In a previous investigation a conformer with the oxygen atom skew with respect to the CC bond was detected [W. Caminati and A. C. Fantoni, Chem. Phys. 105, 59–67 (1986)]. In the present study the conformer with the oxygen atom syn to the double bond and with the hydroxyl hydrogen tunneling through the heavy atom plane has been measured.

Hydrogen bond and torsion-torsion interaction in 2-methylallyl alcohol from the microwave spectrum

The microwave spectrum of 2-methylallyl alcohol, CH 2C(CH 3)CH 2OH, has been investigated for the normal and −OD isotopic species. The assigned transitions are consistent with a hydrogen-bonded conformation having the oxygen atom skew with respect to the CC bond and the hydroxylic hydrogen gauche with respect to the CC bond. From the Stark effect measurements on several transitions the electric dipole moment has been determined. The V 3 barrier to the internal rotation of the methyl group has been obtained in first approximation from the ground state AE rotational splittings. The analysis of the AE doublings has been extended to the first excited state of the methyl group internal rotation and to the first excited state of the CC skeletal torsion. By using a two-dimensional flexible model the potential surface of the two motions has been described with the following parameters V 3 = 605(5) cm −1; V 6 = −13(6) cm −1 for the methyl torsion and k = 1.76(2) cm −1 deg −2; a = −0.0022(4) deg −1 for the skeletal torsion harmonic and cubic force constants.

Amidation of syndiotactic poly(2-methylallyl hydrogen carboxylate)

The amidation of syndiotactic polyacids and the 1H- and 13C-NMR spectroscopic characterization of the resulting polyamides are described. The polyacids have been derived from syndiotactic poly(2-methylallyl alcohol) by esterification with cyclic dicarboxylic acid anhydrides, including N α -protected aspartic acid anhydrides and glutamic acid anhydrides. The poly(hydrogen carboxylate) were in turn condensed with a series of amines, some of which possessed additional functional groups, e.g. (L)-1-phenylethylamine, histamine, and glycine methylester.

PH Effects on the Radical Addition of Hydrogensulfite Ion to Olefins

Abstract The competitive addition of sodium hydrogensulfite to allyl and 2-methylallyl alcohols was investigated at the pH range from 3 to 5. The relative reactivity of allyl alcohol to 2-methylallyl alcohol decreased with increasing pH. Sulfite radical ion was mainly participating in the addition at pH 5, and hydrogensulfite radical at pH 3. From the kinetic analysis of the pH dependence, the ratio of reactivities of allyl alcohol and 2-methylallyl alcohol toward sulfite radical ion was 0.213, and the same ratio toward hydrogensulfite radical was 0.305. Further, the ratio of reactivities of hydrogensulfite radical and sulfite radical ion toward allyl alcohol was 1.32, and the same ratio toward 2-methylallyl alcohol was 0.927. The dissociation constant of hydrogensulfite radical was the order of 3×10−5(pKa=4.5).

Products formed from 2-methylallyl alcohol and rhodium trichloride trihydrate. Determination of the structure of [RhCl2(C8H15O)(4-methylpyridine)2]2 by X-ray crystallography

Rhodium trichloride trihydrate and 2-methyl-allyl alcohol react to give [RhCl2(C8H15O2)]n which with 4-methylpyridine gives [RhCl2(C8H15O2)(4-methylpyridine)2]2, the structure of which has been determined by X-ray diffraction.