Polymerization Of N-butyl Vinyl Ether Research Articles

HL2][P(1,2-O2C6Cl4)3] (L = THF, DMF): Brønsted acid initiators for the polymerization of n-butyl vinyl ether and p-methoxystyrene.

The development of solid, weighable Brønsted acids featuring the hexacoordinated phosphorous(v) anion [TRISPHAT]- are reported. H(DMF)2[1] and H(THF)2[1] {[1]- = [P(1,2-O2C6Cl4)3]-} were synthesized and fully characterized by 1H, 31P, 13C and 2D-NOESY NMR spectroscopy, X-ray crystallography, mass spectrometry and elemental analysis. Both, H(DMF)2[1] and H(THF)2[1] are found to be suitable initiators for the polymerization of n-butyl vinyl ether and p-methoxystyrene. Optimal polymerization results for these single-component initiators were generally obtained at -50 °C where high molecular weight polymers were isolated in high yield. 1H NMR spectroscopic analysis and dynamic light scattering of solutions of the isolated polymers provide evidence for a branched structure which presumably arises from chain transfer.

H(OEt2)2[P(1,2‐O2C6Cl4)3]: Synthesis, Characterization, and Application as a Single‐Component Initiator for the Carbocationic Polymerization of Olefins

The development of novel Brønsted acids featuring the hexacoordinate phosphorus(V) anion [TRISPHAT](-) {[1](-)=[P(1,2-O2C6Cl4)3](-)} are reported. The title compound, H(OEt2)2[1], was synthesized from 1,2-(HO)2C6Cl4 (3 equiv) and PCl5 in the presence of diethyl ether. This compound was fully characterized by (1)H, (31)P and (13)C NMR spectroscopy, X-ray crystallography and elemental microanalysis. Dissolution of H(OEt2)2[1] in acetonitrile results in the slow precipitation of crystalline H(OEt2)(NCMe)[1], which was characterized by X-ray diffraction; however, in CD2Cl2 solution the [TRISPHAT](-) anion protonated and ring-opened. The weighable, solid H(OEt2)2[1] was found to be a competent initiator for the polymerization of n-butyl vinyl ether, α-methylstyrene, styrene and isoprene at a variety of temperatures and monomer-to-initiator ratios. At low temperatures, polymers with M(n) >10(5) were obtained for n-butyl vinyl ether and α-methylstyrene whereas slightly lower molecular weights were obtained with styrene and isoprene (10(4) < M(n) <10(5)). The poly(α-methylstyrene) synthesized at -78 °C is syndiotactic-rich (ca. 87% rr) whereas the polystyrene obtained at -50 °C is atactic. The polyisoprene obtained possessed all possible modes of enchainment as well as branched and/or cyclic structures that are often observed in polyisoprene.

Kinetics and Mechanism of Polymerization of n-Butyl Vinyl Ether Initiated by Dichloroalane (AlHCl2): A New Cationic Initiating System

The carbocationic polymerization of n-butyl vinyl ether (BVE) using the new LiAlH4/AlCl3 initiating system is reported. The polymerizations were carried out in diethyl ether (Et2O), and in a mixture of diethyl ether and dichloromethane (1:1 v/v) at various temperatures, and the kinetics of the polymerizations was studied. The rate constants, the temperature dependence of the rate constants, and the kinetic order of the reactants were determined. The end groups of the polymers were characterized by 1H NMR and MALDI-TOF MS methods. Three different interconvertible end groups, i.e., heteroacetal, homoacetal, and aldehyde, were observed. The tacticity of the polymers formed was determined by 13C NMR. On the basis of detailed kinetic and structural investigations, a direct initiation mechanism for the polymerization is proposed.

Cationic polymerization initiated by onium ions

4-Chlorobenzene-diazonium, CBD +, N-ethoxyisoquinolinium, EIQ +, and N-ethoxy-4-cyanopyridinium, ECP +, ions, in the form of hexafluorophosphate salts, readily initiate in a dark reaction the cationic polymerization of n-butyl vinyl ether, NBVE, isobutyl vinyl ether, IBVE, and N-vinylcarbazole, NVC, in air-saturated dichloromethane solution at room temperature. Hexafluoro-phosphates of diphenyliodonium, Ph 2I +, triphenylsulphonium, Ph 3S +, N-ethoxy-2-methylpyridinium, EMP +, and N-ethoxy-4-phenylpyridinium, EPP +, ions are much less active. They do not initiate the polymerization spontaneously, but cause a very slow conversion of these monomers into polymers. All onium salts examined in this work are quite unreactive in initiating the polymerization of cyclohexane oxide, CHO, and α-methylstyrene, αMSt. However, the polymerization of aerated CHO containing dissolved EIQ +PF 6 − or CBD +PF 6 − is readily initiated upon the addition of vinyl ether (IBVE) or N-vinylcarbazole. This result indicates that cationic species generated by the reaction of EIQ + or CBD + ions with IBVE or NVC are capable of initiating the polymerization of CHO, which itself is unreactive towards the onium ions under investigation.

Polymerization of n-Butyl Vinyl Ether Photoinitiated by the Initiator System Poly(methyl phenyl silane)/N-Ethoxy-2-methylpyridinium Iodide/ZnI2/Benzaldehyde

Polymerization of n -Butyl Vinyl Ether Photoinitiated by the Initiator System Poly(methyl phenyl silane)/ N -Ethoxy-2-methylpyridinium Iodide/ZnI 2 /Benzaldehyde

Polymerization with zeolite catalysts: I. Polymerization of n-butylvinylether by H-mordenite

n-Butylvinylether sorbed from the vapor phase onto hydrogen mordenite powder has been found to polymerize readily near room temperature. In a polymer sample from this reaction the polymer molecules were found to contain a number average of ten monomer units. The reaction over a considerable time interval followed the relations Q t = k √ t + γ k = ( ap + b) F(H 2O) where Q t is the mass uptake (mainly as polymer) at pressure p in time t; k, γ, a and b are coefficients and F(H 2O) is a function of the amount of water in the zeolite. The kinetics have been taken to indicate partial control by a diffusion process in which the monomer penetrates a growing layer of polymer formed around each catalyst particle. The monomer migrates to the catalyst-polymer interface and polymerizes at or near the interface. In small quantities water functioned as a cocatalyst, but around 5% weight uptake F(H 2O) passed through a maximum. The rate of the reaction appeared to reach a maximum between 28 and 30 °C. A carbonium ion mechanism of polymerization is proposed.

チグラー触媒による&lt;I&gt;n&lt;/I&gt;-ブチルビニルエーテルの重合

チグラー触媒による&lt;I&gt;n&lt;/I&gt;-ブチルビニルエーテルの重合