Polyimines from terephthalaidehyde and aliphatic diamines

Summary A series of liquid crystalline copolyimines based on terephthalaldehyde, 1,7-diaminoheptane and 1,9-diaminononane is synthesized. Both melting and isotropization temperatures of the copolyimines are depressed compared to homopolymers P17 and P19. The copolyimines show wider liquid crystalline temperature ranges than the parent homopolyimines.     

Miscibility behavior and coil overlap in ionic blends of phenylated polytriphenylene oxide and poly(methyl methacrylate)

Blends of sulfonated phenylated polytriphenylene oxide and poly(methyl methacrylate‐co‐4‐vinyl pyridine) were examined by dynamic mechanical, Fourier transform infrared, and NMR techniques. A high degree of miscibility was evident from a single drop in a plot of the storage modulus versus the temperature. The presence of ionic moieties due to proton transfer from sulfonic acid to 4‐vinyl pyridine was confirmed by both NMR and IR spectroscopy studies. The coils were found to be close to one another in dimethyl sulfoxide‐d₆ because the aromatic shielding effect of the phenyl rings of the phenylated polytriphenylene oxide units was observed from the upfield shift of most of the protons of poly(methyl methacrylate) in the NMR spectrum. However, the absence of cross peaks in the nuclear Overhauser and exchange spectroscopy experiments suggested that the intermolecular distance between the chains had to be larger than 4 Å. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 728–733, 2003     

Nuclear magnetic resonance studies of ionomers. 6. Polyurethane-polyphosphonate blends

Blending of a poly(ether urethane) with a polyphosphonate obtained by phase transfer catalyzed polycondensation of 4,4′-biphenol and chloromethylphosphonic dichloride generates a phase-separated material. One phase contains the soft segment of the polyurethane. This has been excluded from a high-T_g phase that contains ionic species formed mainly by proton transfer and elimination reactions between the hard segment of the polyurethane and the polyphosphonate. Two glass transitions appear in the blend: one close to the T_g of the polyphosphonate and one belonging to the excluded soft segment of the polyurethane. The low temperature T_g decreases with the increasing content of the polyphosphonate, whereas the high temperature transition increases slightly, indicating an increasing purity of the soft segment and the presence of ionic interactions in the hard segment. The presence of ionic interactions is confirmed by NMR analysis of the blend. Comparison of the spectra of the blends with those of the pure components, along with two-dimensional experiments, indicate a reaction involving the chloromethyl groups of the polyphosphonate and the nitrogens of the polyurethane.     

Polycondensation of tetrachlorobisphenol a with chloromethylphosphonic dichloride. 1H-NMR kinetic study

The temperature-programmed polycondensation of tetrachlorobisphenol A with chloromethylphosphonic dichloride is carried out in the sample tube of an NMR spectrometer. From the spectra during polycondensation, the instantaneous concentration of components can be determined. Phosphorus and chlorine-containing polymers with flame-retardant properties are obtained.     

Polycondensation of N-methyl carbazole with dihalogenomethane and some properties of the polymer

Summary N-methyl carbazole was reacted with dichloromethane or dibromomethane in the presence of AlCl₃,SbCl₅ or SnCl₄ to give a polymer. In several cases insoluble structures with semiconductive properties were obtained. With dichloromethane and AlCl₃, a linear polymer: poly(N-methyl-3,6-carbazolyl methylene) (PMCM) was obtained. Charge transfer complexes of PMCM with acetyl-2-hydroxyethyl-3,5-dinitrobenzoate generate a signal in the ESR spectrum, whose intensity does not depend on illumination. Films of complexes of PMCM are photoconductive with a maximum photocurrent in the visible region.Dedicated to Professor H.-J. Cantow on the occasion of his 60. birthday     

Intramolecular charge transfer complexes

Summary Radical copolymerization of 2,4-dinitrophenyl methacrylate (DNPM, M₂) with N-(2-hydroxyethyl)-3,6-dichlorocarbazolyl methacrylate (HECl₂CM, m₁) and N-(2-hydroxyethyl)-3,6-dichloro-carbazolyl acrylate (HEC1₂CA, M₁) takes place by the simple terminal mechanism having the parameters: r₁=0.13 r₂=1.65 (M₁=HECl₂CM) r₁=0.13 r₂=1.20 (M₁=HECl₂CA) Intramolecular complexation differences for the two obtained systems are explained by configurational differences.Dedicated to our Prof. C.I. Simionescu in occasion of his 60th anniversary6th part in this series: reference (6) Abbrevuiations The monomer mixture is indicated by the initials of the two monomers (for example HECA-PM) and their copolymer by the initials separated by -co- (for example HECA-co-PM).     

Method for reactivity ratio determination in high-conversion copolymerisations by means of 1H-n.m.r. spectroscopy

Copolymerisation of methyl methacrylate and styrene is carried out in the n.m.r. spectrometer's sample tube, measuring the comonomer concentration against time evolution. The data are processed according to the integrated Mayo-Lewis and Fineman-Ross equations in order to obtain the reactivity ratios values. The applicability, advantages and limits of the method are discussed.     

Synthesis and characterization of some aromatic polyphosphonates

Novel aromatic polyphosphonates are synthesized by polycondensation of chloromethyl (methyl, phenyl) phosphonic dichloride with bisphenols using three procedures: melt, solution, and phase transfer catalysis. The molecular weights and spectral characteristics are presented. Mixtures of the polyphosphonates with polyacrylonitrile and nylon 66 are compatible only when the chloromethyl group is present. Eight percent of polyphosphonate in the mixture confers flame resistance to the polymers.     

Intramolecular charge transfer complexes

Summary In chloroform solutions, 2-naphtyl methacrylate (M₁) and picryl methacrylate (M₂) give a charge transfer complex (CTC) having a 11 composition. The CTC plays a decisive part in the radical copolymerization of these monomers. The reactivity ratio values for this system are : r₁₂=30; r_1C= 0.14; r_1C1=0.19; and r_1C2=0.53.The obtained copolymers are intramolecular CTC, and their charge transfer interactions depend on copolymer composition and conformation.