Unvernetzte Epoxid-Amin-Additionspolymere, 31. Polykationen auf Basis von Epoxid-Amin-Additionspolymeren. Herstellung und Eigenschaften

New cationic polymers ( 4 and 8 ) with-defined separation of charges were obtained by N-quaternization of epoxide-amine addition polymers with benzyl chloride, butyl bromide and methyl iodide. The termal decomposition of 4 and 8 starts at temperatures between 320 and 370°C. Dielectric measurements in the frequency range 10² to 10⁷ Hz show a dependence of the conductivity on the temperature. The cationic polymer 4d exhibits a conductivity of δ = 10^?6 S/cm at 89°C and 10⁶ Hz.     

Conducting polymers from anodic coupling of some N,N′-bridged 2,2′-bipyrrolyl monomers

Anodic coupling in CH₃CN + 0,1 M tetraethylammonium perchlorate of some 2,2′-bipyrrolyl monomers bridged by X groups at the N,N′-positions (X = ? CH?CH? ( 1 ), o-C₆H₄ ( 2 ) ? CH₂? ( 3 ), ? (CH₂)₂? ( 4 ) and ? (CH₂)₃? ( 5 )) produces conducting, α-coupled polypyrroles (from IR spectroscopy), containing 0,25–0,30 counteranions per pyrrole ring (from elemental analysis). The in-situ conductivity spans from values commonly found for N-substituted polypyrroles (4 ? 10^?3 S/cm for 5 ) to unusually high values (2,5 S/cm for 4 ). A linear correlation between redox potentials and log of conductivities of the polymers evidences the influence of the polymer electronic properties of charge transport.     

Electrosynthesis of poly(N-ethyl-3,6-carbazolediyl) catalyzed by a Ni(0)-based complex

Poly(N-ethyl-3,6-carbazolediyl) was synthesized by electroreduction of the NiBr₂/2,2′-bipyridine/3,6-dibromo-N-ethylcarbazole system in N,N-dimethylacetamide. Both gel permeation chromatography analyses of the polymer formed and electrochemical studies of the system during the course of polymerization in homogeneous phase point at a constant efficiency of the catalytic complex. The latter generates potentially active species which contain the transition metal inserted into a C? Br bond. Mechanisms of formation of the growing chains are proposed on the basis of the electrochemical behaviour of the catalytic system. Chemical doping of the polymer leads to a material the conductivity of which is in the range 10^?4 < σ/(Ω^?1 · cm^?1) < 10^?3.     

Interaction of polystyryl radical with copper(II) complexes

The polymerization of styrene initiated by 2,2′-azoisobutyronitrile (AIBN) was studied in N,N-dimethylformamide (DMF) solution at 60°C in the presence of tetrakis(N,N-dimethylformamide)copper(II) perchlorate, and also in the presence of its monoazido copper(II) complex [Cu(DMF)₃N₃]⁺. The monoazido complex in DMF was prepared in situ by mixing solid sodium azide with tetrakis(N,N-dimethylformamide)copper(II) perchlorate in a mole ratio of 1:1. The nature of the complex was established by Job's method. The equilibrium constant K for the reaction [Cu(DMF)₄]²⁺ + N ? [Cu(DMF)₃N₃]⁺ + DMF determined by the limiting logarithmic method was found to be 1,25 · 10⁴l · mol^?1. The presence of [Cu(DMF)₄]²⁺ ions in the polymerization systems caused retardation, but [Cu(DMF)₃N₃]⁺ ions produced well defined induction periods. The rate constants at 60°C for the interaction of polystyryl radical towards [Cu(DMF)₄]²⁺ and [Cu(DMF)₃N₃]⁺ ions were calculated to be 6,6 · 10² and 5,74 · 10⁴ l · mol^?1 · s^?1, respectively.     

Laser light scattering studies of soluble high performance fluorine-containing polyimides, 1. Polyimide synthesized from 2,2′-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride and 2,2′-(trifluoromethyl)-4,4′-biphenyldiamine

Five fractions of a polyimide synthesized from 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2′-(trifluoromethyl)-4,4′-biphenyldiamine (PFMB) (6FDA/PFMB) in tetrahydrofuran (THF) at 30°C were investigated by a combination of static and dynamic laser light scattering (LLS). The relations of 〈R_h〉 (nm) = 2.38 x 10^?2 M _w^0.560 and A₂ (mol · cm^?3 · g^?2) = 2.1 × 10^?1 M _w^?0.43 were established, where M _w, 〈R_h〉 and A₂ are weight-average molecular weight, average hydrodynamic radius and second virial coefficient, respectively. A combination of M _w and the translational diffusion coefficient distribution G(D) leads to a relation of D(cm²/s) = 2.41 × 10^?4 M ^0.564. With this relation, we successfully convert each G(D) into a corresponding molecular weight distribution (MWD). On the basis of the Benoit-Doty theory, we found that the persistence length and the Flory characteristic ratio C_∞ of the 6FDA-PFMB chain are ～3.3 nm and ～40, respectively, indicating that the 6FDA-PFMB chain is more extended than typical random-coil chains. On the other hand, the ratio of the radius of gyration to the hydrodynamic radius, i.e., 〈R_g〉/〈R_h〉 ～ 1.8, together with the values of the exponents (～0.56) indicate that the 6FDA-PFMB chain has a coil chain conformation. Therefore, the 6FDA-PFMB chain has an extended coil conformation in THF at 30°C.     

Polymer‐in‐ionic‐liquid electrolytes

In order to achieve high conductivity in a polymer electrolyte, polymer‐in‐ionic‐liquid electrolytes have been explored. It is found in this study that poly[vinylpyrrolidone‐co‐(vinyl acetate)] (P(VP‐c‐VA)) in 1‐ethyl‐3‐methylimidazolium bis(trifluoromethyl sulfonyl) amide (EtMeIm⁺Tf₂N⁻) and poly(N,N‐dimethyl acrylamide) (PDMAA) in trimethyl butyl ammonium bis(trifluoromethane sulfonyl) amide (N₁₁₁₄⁺Tf₂N⁻) produce ion‐conducting liquids and gels. The P(VP‐c‐VA)/ EtMeIm⁺Tf₂N⁻ mixture has a conductivity around 10⁻³ S · cm⁻¹ at 22 °C, for copolymer concentrations up to 30 wt.‐%. Thermal analysis shows that the T_g of the P(VP‐c‐VA)/ EtMeIm⁺Tf₂N⁻ system is well described by the Fox equation as a function of polymer content. Poly(methyl methacrylate) (PMMA)/ EtMeIm⁺Tf₂N⁻ gel electrolytes were prepared by in‐situ polymerisation of the monomer in the ionic liquid. In the presence of 0.5–2.0 wt.‐% of a crosslinking agent, these PMMA‐based electrolytes displayed elastomeric properties and high conductivity (ca. 10⁻³ S · cm⁻¹) at room temperature.

Conductivity versus temperature in crosslinked PMMA/ EtMeIm⁺Tf₂N⁻ gel electrolytes with different concentrations of crosslinking agent.     

Estimation of the conformational characteristics of polyurethane chains

Linear polyurethanes (PUR-D_k) were prepared by reacting 4,4′-methylenediphenyl diisocyanate (MDI) with low-molecular-weight diols HO (CH₂)_k OH (k = 2, 3, 4, and 6) and fractionated by precipitation or extraction with mixtures of N,N-dimethylformamide (DMF) and dibutyl ether (DBE). The fractions were characterized by their weight-average molecular weights M _w (light scattering) and intrinsic viscosities [η] in DMF (good solvent) and mixtures of DMF with DBE (poor solvents). The Kuhn statistical segment length l_K was evaluated from the intrinsic viscosities in poor solvents. Low values of l_K, (12 to 14) × 10⁻⁸ cm, indicate that benzene rings and virtual double bonds (urethane groups) confine neighbour interactions to bonds within the repeating units and assure independent rotations at the bonds adjoining them.     

A Genome‐Wide Search for Type 2 Diabetes Susceptibility Genes in an Extended Arab Family

Twenty percent of people aged 20 to 79 have type 2 diabetes (T2D) in the United Arab Emirates (UAE). Genome‐wide association studies (GWAS) to identify genes for T2D have not been reported for Arab countries. We performed a discovery GWAS in an extended UAE family (N = 178; 66 diabetic; 112 healthy) genotyped on the Illumina Human 660 Quad Beadchip, with independent replication of top hits in 116 cases and 199 controls. Power to achieve genome‐wide significance (commonly P = 5 × 10^?8) was therefore limited. Nevertheless, transmission disequilibrium testing in FBAT identified top hits at Chromosome 4p12‐p13 (KCTD8: rs4407541, P = 9.70 × 10^?6; GABRB1: rs10517178/rs1372491, P = 4.19 × 10^?6) and 14q13 (PRKD1: rs10144903, 3.92 × 10^?6), supported by analysis using a linear mixed model approximation in GenABEL (4p12‐p13 GABRG1/GABRA2: rs7662743, P_adj‐agesex = 2.06 × 10^?5; KCTD8: rs4407541, P_adj‐agesex = 1.42 × 10^?4; GABRB1: rs10517178/rs1372491, P_adj‐agesex = 0.027; 14q13 PRKD1: rs10144903, P_adj‐agesex = 6.95 × 10^?5). SNPs across GABRG1/GABRA2 did not replicate, whereas more proximal SNPs rs7679715 (P_adj‐agesex = 0.030) and rs2055942 (P_adj‐agesex = 0.022) at COX7B2/GABRA4 did, in addition to a trend distally at KCTD8 (rs4695718: P_adj‐agesex = 0.096). Modelling of discovery and replication data support independent signals at GABRA4 (rs2055942: P_{adj‐agesex‐combined} = 3 × 10^?4) and at KCTD8 (rs4695718: P_{adj‐agesex‐combined} = 2 × 10^?4). Replication was observed for PRKD1 rs1953722 (proxy for rs10144903; P_adj‐agesex = 0.031; P_{adj‐agesex‐combined} = 2 × 10^?4). These genes may provide important functional leads in understanding disease pathogenesis in this population.     

Reactive poly(2-vinyl-4,4-dimethyl-5-oxazoione) and poly[(2-vinyl-4,4-dimethyl-5-oxazolone)-co-(methyl methacrylate)]s. Synthesis,characterization and chemical modification with 4-methoxy-4′-(β-aminoethoxy)biphenyl

Poly(2-vinyl-4,4-dimethyl-5-oxazolone) ( P₀ ) and poly[(2-vinyl-4,4-dimethyl-5-oxazolone)-co-(methyl methacrylate)]s with increasing content of methyl methacrylate units ( P₁–P₄ ) were synthesized and characterized. NMR spectra were discussed in terms of monomer sequence distribution and tacticity effects. The reaction of 4-methoxy-4′-hydroxybiphenyl ( 1 ) with 2-ethyl-2-oxazoline was utilized to prepare 4-methoxy-4′-(β-aminoethoxy)biphenyl ( 3 ) through the intermediate 4-methoxy-4′-[(N-propanoyl)-β-aminoethoxy]biphenyl ( 2 ). The homopolymer P ₀ and two copolymers P ₂ and P ₃ were functionalized with 4-methoxybiphenyl side groups by reaction with 3 via a ring-opening process in N,N-dimethylformamide (DMF) or 1,2-dichloroethane. The resulting copolymers P₅–P₈ were characterized by ¹H and ¹³C NMR. The highest degree of functionalized units was obtained in DMF at 80°C.     

Synthesis and characterization of processable conducting polyazomethines

A series of the wholly aromatic polyazomethines (PAM) having flexible side chains was synthesized by solution and melt polycondensation of 2,5-dialkoxyterephthalaldehydes and aromatic diamines. The solution polycondensation was carried out at 80°C for 24 h in 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU)/N-methyl-2-pyrrolidone (NMP) mixtures. The melt polycondensation was conducted in N₂ atmosphere at 200°C for 2,8 h. All of the polymers were soluble in CCl₄, CHCl₃, THF, benzene, toluene, etc. The inherent viscosity (η_inh), measured at 30°C in CHCl₃, was 0,13–0,32 dL/g, and 5% weight loss in TG curves appeared at 365–390°C in N₂ atmosphere. The electrical conductivities of I₂-treated dialkoxy-substituted PAM were low, 10^?4 < σ < 10^?6 S/cm, compared with unsubstituted I₂-treated PAM.     

Reactivity in radical and anionic copolymerizations of 4-(trimethylsilyl)styrene. Synthesis of soluble poly{(1,4-divinylbenzene)-co-[4-(trimethylsilyl)styrene]}

Radical copolymerization of 4-(trimethylsilyl)styrene (TMSS) with styrene were carried out to estimate the reactivity of TMSS. The monomer reactivity ratios r₁ and r₂ in the radical copolymerization of TMSS (M1) with styrene (M2) were evaluated as 0,28 and 0,48, respectively. The value r₁ · r₂ (= 0,13) being smaller than unity indicates that the trimethylsilyl group at para position behaves as an electron-withdrawing substituent. Reactions of lithium diethylamide with TMSS in the presence of diethylamine, gave the 1:1 addition product 1-[2-(N,N-diethylamino)-ethyl]-4-(trimethylsilyl)benzene. Kinetic analysis showed that the second-order rate constant (k) for this addition reaction is 34,4 · 10^?4 dm³ · mol^?1 · s^?1, which is by a factor of 2 larger than that for the reaction with styrene (k = 16,0 · 10^?4 dm³ · mol^?1 · s^?1). The fact is also compatible with the above consideration for the r₁ · r₂ values. Lithium diisopropylamide initiated anionic copolymerizations of TMSS with 1,4-divinylbenzene (DVB) were also examined. The polymerizations proceed smoothly without any gel formation and the resulting copolymers are soluble in various common solvents such as benszene, tetrahydrofuran, chloroform, etc. Thus, novel organosilicon-containing polymers having appropriate amounts of reactive pendent vinyl groups are easily synthesized.     

The initiation of polymerization of unsaturated tertiary amines with carboxylic acids

The polymerization rate (R_p) of N-methyl-N-phenyl-2-aminoethyl methacrylate (MPAEMA) initiated with 2,2' -azodiisobutyronitrile (AIBN) at 50°C increased considerably after the addition of CCI₃COOH, and distinctly after the addition of CH₃COOH. R_p in a benzene solution of 2 mol. dm^?3 MPAEMA and 5 · 10^?2 mol. dm^?3 CCl₃COOH (without AIBN) was 13% · h^?1. [η] of the obtained polymer corresponded to 64 cm³ · g^?1. The polymerization order of MPAEMA initiated with CCl₃COOH is 0,93 with respect to monomer and 0,51 with respect to CCl₃COOH. The overall activation energy of polymerization of MPAEMA calculated from the temperature dependence of R_p between 20 and 50°C is 43 ± 1,2 kJ · mol^?1. In a benzene solution of 2 mol.dm^?3 MPAEMA, 5 · 10^?2 mol · dm^?3CCl₃COOH and 5 · 10^?3 mol · dm^?3 1,4-benzoquinone at 50°C the polymerization does not proceed for 6 h. In a benzene solution of 2 mol · dm^?3 4-dimethylaminostyrene (4-DMAS) and 2 mol · dm^?3 CH₃COOH (without AIBN), 40% of monomer polymerized within one hour. [η] of the polymer was 4 cm³ · g^?1. The overall activation energy of polymerization of 4-DMAS in the presence of CH₃COOH is ca · 54 kJ · mol^?1. The addition of 5 · 10^?3 1,4-benzoquinone slows down the polymerization rate only slightly. The effect of acids on the elementary polymerization reactions is characterized.     

Thiol‐Ene Click Chemistry as a Tool for a Novel Family of Polymeric Ionic Liquids

Functionalized pyrrolidinium compounds, 3‐((2‐hydroxyethylthio)methyl)‐1,1,4‐trimethylpyrrolidinium and 3‐((2‐carboxyethylthio)methyl)‐1,1,4‐trimethylpyrrolidinium chlorides, are prepared from N,N‐diallyl‐N,N‐dimethylammonium chloride by radical thiol‐ene addition and are utilized as building blocks in the synthesis of “ionic liquid‐like monomers.” “Polymeric ionic liquids” with highest molecular weights are obtained in water from chloride monomers followed by ionic exchange with lithium bis(trifluoromethylsulfonyl)imide. Synthesized polymers demonstrate negligible water absorption (<0.1 wt%). Copolymerization with polyethyleneglycol di‐ and monomethacrylates leads to the conductive self‐standing tough films with ionic conductivity up to 2.8 × 10^?7/1.3 × 10^?6 S cm^?1 at 25 °C.     

Synthesis and optical properties of polyurethanes containing a highly NLO active chromophore

Two types of new polyurethanes with a highly NLO active chromophore, 2-[4-[4-[bis(2-hydroxyethyl)amino]phenylazo]benzylidene]malonitrile (HAPM), in the polymer side chain were synthesized (PU1-DCN and PU2-DCN) and characterized. The diisocyanate components of the polymers are 2,4-tolylene diisocyanate and 3,3′-dimethoxybiphenyl-4,4′-ylene diisocyanate. The molecular weights of PU1-DCN and PU2-DCN were determined to be M̄_w = 23000 (M̄_w/M̄_n = 2.19) and M̄_w = 22000 (M̄_w/M̄_n = 2.34), respectively. The final products are readily soluble in polar aprotic organic solvents, like tetrahydrofuran, N,N-dimethylformamide, cyclohexanone, etc. Good optical quality films were obtained by spin coating. The glass transition temperatures of both polymers were found to be 158–159°C. They showed no melting points in the DSC curves, suggesting an amorphous phase. It was found that the electro-optic coefficient of PU1-DCN was r₃₃ = 62.7 pm · V⁻¹ at 633 nm wavelength. The macroscopic second-order hyperpolarizability at 1064 nm wavelength was determined to be χ⁽²⁾ = 136 pm · V⁻¹ for PU1-DCN and χ⁽²⁾ = 120 pm · V⁻¹ for PU2-DCN.     

Functional metal-porphyrazine derivatives and their polymers, 1. Synthesis of metal-[2,9or10(or 2,16or17)bis(3,4-dicarboxybenzoyl)]phthalocyanine derivatives

The diimide of metal-[2,9or10(or 2,16or17)bis(3,4-dicarboxybenzoyl)]phthalocyanine(diPc) (where i = imide) 2 or 3 were prepared from 3,4,3′,4′-benzophenonetetracarboxylic dianhydride (BTDA) ( 1 ), phthalic anhydride (PA), urea, and metal salts such as CuCl₂, CoCl₂, and FeCl₃ etc. at 170°C. In the case of copper, the diPc monomer 2 or 3 and the dimer 4 or 5 could be synthesized. Those copper complexes are stable to all of the chemical procedures. However, the core metals of Fe(III), Co(II), Ni(II) and Zn(II)-diPc were partially removed in the acid treatment. Metal phthalocyanine derivatives which have four carboxyl groups in the peripheral site, metal-[2,9or10(2,16or17)bis(3,4-dicarboxybenzoyl)] phthalocyanine(daPc) (a = acid) 6 or 7 , were synthesized by hydrolysis of the metal-diPc. The metal-daPc are soluble in water, in aprotic solvents such as N,N′-dimethylformamide, and also in sulfuric acid. The physicochemical properties of some metal-daPc derivatives were investigated.     

Bestimmung der geschwindigkeitskonstanten und der effektivitäten beim zerfall von 2,2′-azoisobutyronitril in styrol,N-vinyl-2-pyrrolidon und methylmethacrylat

The decomposition rate constants k_d of initiators can be determined by a new method directly in monomers as solvents. If a suitable inhibitor is added to a monomer mixture with the initiator the latter decomposes nearly without monomer conversion. The initiator concentration—after the inhibitor is consumed—can be found by means of the dilatometrically determined polymerization rate after the induction period. The functional connection between polymerization rate and initiator concentration found without inhibitor is used as a calibration curve for that purpose. The dilatometrical measurements were made in the monomers styrene and N-vinyl-2-pyrrolidone using 2,2′-azoisobutyronitrile (AIBN) as initiator and p-quinone as inhibitor. The following decomposition rate constants were found: k_d=1,52 · 10^?5 S^?1 (styrene) and k_d=1,62 · 10^?5 S^?1 (N-vinyl-2-pyrrolidone), which is in agreement with literature values. Initiator efficiencies f were calculated: f=0,46 (styrene), f=0,47 (N-vinyl-2-pyrrolidone). In methyl methacrylate (MMA) 2,2′-diphenyl-1-picrylhydrazyl (DPPH) was used as inhibitor. Under certain conditions the product k_df can be calculated from the consumption rate of DPPH. The value found in MMA (k_df=3,7 · 10^?6 s^?1) is lower than that reported in literature (6,45 · 10^?6 s^?1).     

Relaxation and charge transport in mixtures of zwitterionic polymers and inorganic salts

Dielectric spectroscopy is employed to analyze the molecular dynamics and the charge transport in mixtures of zwitterionic polymers of the type poly{3 [N(ω-methacryloyloxyalkyl)] N, [N-dimethylammonio propanesulfonate] with sodium iodide in the frequency range of 10²Hz–10⁷ Hz and in the temperature range of 110 K-400 K. The amount of inorganic salt added varies from 0–200 mol-% relative to the number of zwitterionic groups present in the polymer, contributing strongly to the conductivity. One relaxation process is observed whose relaxation rate depends strongly on the length of the aliphatic spacer between the polymethacrylate main chain and the zwitterionic group. Exhibiting an Arrhenius-like temperature depence with activation energy E_A = 47 KJ/mol, this relaxation process is assigned to fluctuation of the quaternary ammonium groups in the side chains. At higher temperatures, the dielectric properties and the conductivity are primarily dominated by the mobile inorganic ions: conductivity strongly depends on the salt concentration, showing a pronounced electrode polarization effect. The frequency and salt concentration, dependences of the conductivity can be quantitatively described as hopping of charge carriers being subject to spatially randomly varying energy barriers. For the low-frequency regime and for the critical frequency marking the onset of the conductivity's dispersion, the Barton-Nakajima-Namikawa (BNN) relationship is fulfilled.     

Potentials and small-signal impedances of platinum microelectrodesin vivo andin vitro

Pt-black covered metal microelectrodes were made with leading-off areas between 3μm² and 10μm². The resting potential was measured relative to an Ag/AgCl electrode and was between 0·1 and 0·9 V in 120 mM NaCl for input currents less than 10^?12 A. The potential shifted about 100 mV when buffers were added or O₂ removed by bubbling with N₂. Input currents of the order ?10^?10 A made the resting potential as negative as ?1·0 V depending on the O₂ and N₂ tensions. The small-signal-impedance corresponded roughly to a capacitor of 15 pF/μm²; the resistive series component was numerically 1/10 of the imaginary series component at 10 Hz and 1/2 that at 1000 Hz. The responses in potential to large current pulses (±10^?8 A) were limited by those potentials at which the formation of gases took place (1·1 to 1·3 V for O₂ and Cl₂, and ?1·4 V for H₂). In brain the resting potential for each electrode varied with location, being not more than 0·2 V for input currents less than 10^?12 A, but as much as 2 V for input currents of about 10^?10 A. The measurements suggest that these variations reflect the spatial variation of pO₂ in the brain. Similarly the potential response to large current pulses (±10^?8 A) in the brain was also dependent of the local pO₂. The real series component of the small-signal impedance in brain was about twice that in saline, while the imaginary series component was about 40% larger than in saline.     

Molecular dynamics in liquid crystalline N-acylated oligoethylenimines as studied by broadband dielectric spectroscopy

The molecular dynamics and the charge transport in six liquid crystalline N-acylated oligoethylenimines were investigated by dielectric spectroscopy. The dielectric spectra in the temperature range from 125 K up to 400 K and in the frequency range between 10⁻² Hz and 10⁷ Hz could be described by a conductivity contribution and three relaxation processes. The molecular assignment of the α-process is a relaxation of the rigid benzamide unit. Its mean relaxation time is influenced by the length of the alkoxy side chains, the spacer length (ethylene or propylene groups) and the neighboring repeating units. In the columnar mesophase this process is cooperative due to sterical hindrance. A normalized g-factor expressing the intermolecular cooperativity was calculated. The cooperativity increases when approaching the glass transition temperature. The γ-process is assigned to local librational motions of the alkoxy side chain involving the ether linkage. It has an Arrhenius-like temperature dependence (activation energy ΔE_a = 22–32 kJ/mol). The β-process is presumably a libration at the end of the alkyl chains. The conductivity contribution to the imaginary part of the dielectric function ε″ is frequency independent except for very low frequencies where electrode polarization causes a decrease in the measured conductivity. The charge transport is strongly influenced by the phase transitions isotropic to columnar and columnar to crystalline, but not by the glass transition.     

Radical Polymerization and Copolymerization of 12‐[(N‐Methacryloyl)carbamoyloxy]octadecanoic Acid

Radical polymerization of 12‐[(N‐methacryloyl)carbamoyloxy] octadecanoic acid ( 1 ) was kinetically and ESR spectroscopically investigated in acetone, using dimethyl 2,2′‐azobisisobutyrate ( 2 ) as initiator. The polymerization rate (R_p) is given by R_p = k [2]^0.7[1]^1.4 at 50°C. Propagating poly( 1 ) radical was observed as a 13‐lines spectrum by ESR under the actual polymerization conditions. The ESR‐determined k_p values (1.8–7.9 L/mol·s) are much lower than those of usual methacrylate monomers. The rate constant (k_t) of termination was determined to be k_t = 1.0–2.7·10⁴ L/mol·s from decay curve of the propagating radical. The Arrhenius plots of k_p and k_t gave the activation energies of propagation (63 kJ/mol) and termination (24 kJ/mol). A significant solvent effect was observed on the radical polymerization of 1 . The copolymerizations of 1 with styrene(St) and acrylonitrile were examined at 50°C. Copolymerization parameters obtained for the 1  (M₁)/St (M₂) system are as follows; r₁ = 0.73, r₂ = 0.57, Q₁ = 0.83, and e₁ = 0.13.