Problems of unit variability in metal-containing polymers

The main types of unit variability in metal-containing polymers, including those typical of traditional polymers and those peculiar only to polymers with metal-containing groups, are surveyed and classified. The methods for controlling unit variability and the possibility of taking it into account and using it for practical purposes are analyzed. The main problems in this field and the prospects for their solution are considered. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2403–2420, December, 1998.     

Visible Light Mediated Fast Iterative RAFT Synthesis of Amino‐Based Reactive Copolymers in Water at 20 °C

The attempts to mediate iterative RAFT polymerization of ionic monomers through visible light irradiation in water at 20 °C is reported, in which complete conversions are attained in several tens of minutes and the propagation suspends/restarts immediately for multiple times on cycling irradiation. This technique suits the one‐pot synthesis of NH₂/imidazole‐based polymers with tuned structures from homo to random, block, random‐block, and block‐random‐block, thus is robust and promising to control the sequence of the ionized water‐soluble reactive copolymers.

     

Development and application of novel ring‐opening polymerizations to functional networked polymers

This Highlight gives an overview of the recent progress in development of new ring‐opening polymerizations (ROPs) and their applications to functional networked polymers in our group. The described ROPs involve thermally induced polymerization of 1,3‐benzoxazine, anionic alternating copolymerizations of epoxides and lactones, and those exhibiting equilibrium nature. These ROPs were successfully applied to the syntheses of the relevant networked polymers, leading to their distinctive features such as high thermal stability, small volume shrinkage, and selective decrosslinking ability, which enabled design and development of next generation materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4847–4858, 2009     

Synthesis and characterization of novel crosslinkable polymers with a nonlinear optical chromophore as a pendant group

New crosslinkable polymers with a nonlinear optical (NLO) active chromophore as a pendant group were synthesized by condensation chain polymerization via palladium‐catalyzed carbon–carbon coupling reactions. The polymerization yields were almost quantitative between the diiodobenzene (DIB) and diethyldipropargyl malonate (DEDPM) or 4‐(dimethylamino)‐4′‐(6‐dipropargylacetoxypropylsulfonyl)stilbene (DASS‐6) monomers. To improve the molecular weight and mechanical properties of the NLO active polymer, we carried out the copolymerization with DIB and DASS‐6 with various feed ratios of DEDPM. The resulting polymers were soluble in organic solvents and spun‐cast onto indium tin oxide‐coated glass substrates to make thin films. The molecular structures of the resulting polymers were characterized with various instrumental methods to confirm the carbon–carbon coupling reactions between the DIB and diacetylene monomers. The absorption of the ultraviolet–visible spectrum of the resulting polymers was drastically reduced after thermal curing at 160 °C because of the crosslinking of the reactive acetylene group in the polymer backbone. The electrooptic coefficient (r₃₃) measured at 1.3 μm ranged from 7 to 15 pm/V. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4025–4034, 2001     

Polar Isotactic and Syndiotactic Polypropylenes by Organozirconium-Catalyzed Masking-Reagent-Free Propylene and Amino–Olefin Copolymerization

Polar functionalized isotactic and syndiotactic polypropylenes (PPs) are synthesized by direct, masking-reagent-free propylene and amino–olefin (AO, CH₂=CH(CH₂)_xNⁿPr₂, x=2, 3, 6) copolymerizations using the activated precatalysts rac-[Me₂Si(indenyl)₂]ZrMe₂ and [Me₂C(Cp)(fluorenyl)]ZrMe₂, respectively. Polymerization activities at 25 °C are as high as 4208 and 535 kg/(mol h atm) with AO incorporation up to 4.0 mol % and 1.6 mol %, respectively. Remarkably, introducing the amino-olefin comonomers significantly enhances stereoselection for both isotactic (mmmm: 59.5 %→91.0 %) and syndiotactic (rrrr: 66.3 %→81.3 %) products.     

Poly(3,4‐ethylenedioxythiophene)‐based copolymers for biosensor applications

The synthesis of 3,4‐ethylenedioxythiophene (EDOT) derivatives bearing functional groups is described. Their electrochemical characteristics were investigated with cyclic voltammetry and ultraviolet–visible spectroscopy. Various copolymers of EDOT and modified EDOT containing hydroxyl groups were electrochemically prepared. The ability to bind proteins to the surface of these copolymers was investigated through the covalent coupling of glucose oxidase. The obtained materials were used as working electrodes and were shown to be able to amperometrically detect glucose under aerobic and anaerobic conditions. Possible applications of these materials as biosensors are discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 738–747, 2002; DOI 10.1002/pola.10159     

Ostwald Ripening of Two-Component Disperse Phase Miniemulsions Containing Monomer and Reactive Costabilizer

The Ostwald ripening behavior of the two-component miniemulsions of MMA/SMA, ST/SMA, MMA/LMA, and ST/LMA was investigated. Kabal'nov equation predicted the Ostwald ripening rate data reasonably well when the volume fraction of reactive costabilizer was lower than 0.02–0.03, but it failed to describe the experimental data over the whole costabilizer volume fraction range (0.01–0.05). An empirical equation with two adjustable parameters K₁ and K₂ was then proposed to adequately predict the Ostwald ripening rate data. The greater the value of K₁ (or K₂), the more effective is the costabilizer in stabilizing miniemulsion droplets against the diffusional degradation process.     

Novel carbamoyl phosphonate monomers and polymers from unsaturated isocyanates

Carbamoyl phosphonate derivatives of methacrylic acid and α-methyl styrene were synthesized in good yield by reacting dimethyl and diethylphosphite with isocyanato ethylmethacrylate (IEM) or with meta-isopropenyl-α,α-dimethylbenzylisocyanate (m-TMI). The IEM derivatives yield soluble homopolymers with common radical initiators. The m-TMI carbamoyl phosphonates were copolymerized with styrene and with acrylates yielding soluble materials with better than 50 mol % incorporation of the phosphonate monomer. The side chain carbamoyl phosphonate group drastically lowers the T_g relative to those of the parent polymers. Thermogravimetric studies suggest the NHC(O)? P(O)(OR)₂ bond to be stable to about 225°C. The radiopacifying salt UO₂(NO₃)₂6 H₂O yields transparent films with the phosphonate-containing polymers. The T_g increases with uranyl content. © 1993 John Wiley & Sons, Inc.     

Reactive Surfactant in the Emulsion Copolymerization of Methyl Methacrylate and Octyl Acrylate

The emulsion copolymerization of methyl methacrylate and octyl acrylate was studied using a reactive surfactant ammonium sulfate allyloxy nonylphenoxy poly(ethyleneoxy) (10) ether (DNS‐86), and a conventional surfactant sodium dodecylbenzene sulfonate (DBS) with a similar structure as a comparison sample. A series of latex samples have been prepared with two kinds of surfactants, and their properties have been characterized and compared. ¹H‐NMR proves that the reactive surfactant has been incorporated into the resulting copolymers. The atomic force microscopy (AFM) proves that the reactive surfactant DNS‐86 migrate to the surface of the latex film to a much less degree than the conventional surfactant DBS. Transmission electron microscopy (TEM) demonstrates that there are some differences in the particle morphologies. The stability and water‐resistance of the latex films prepared by reactive surfactant DNS‐86 are better than those prepared by the conventional surfactant DBS.     

Rheological behavior of associating ionic polymers based on diallylammonium salts containing single-, twin-, and triple-tailed hydrophobes

The cycloterpolymerizations of N,N-diallyl-(4-octyloxy)benzyl-, N,N-diallyl-(3,5-dioctyloxy)benzyl-, and N,N-diallyl-(3,4,5-trioctyloxy)benzyl-ammonium chloride (0-8 mol%) with hydrophilic monomer N,N-diallyl-N-carboethoxymethylammonium chloride and sulfur dioxide afforded a series of cationic polyelectrolytes (CPE). The CPEs were treated with HCl and NaOH to produce the corresponding pH-responsive cationic acid salts (CAS) and polybetaines (PB), anionic polyelectrolytes (APE) as well as polymers PB/APE containing various proportions of zwitterionic (PB) and anionic fractions (APE) in the polymer chain. Likewise, the cycloterpolymerizations of these single-, twin-, and triple-tailed hydrophobes (0-12 mol%) with hydrophilic monomer diallyldimethylammonium chloride and sulfur dioxide afforded a series of CPE in excellent yields. The polymers were characterized by different techniques including NMR and IR. The solution properties of the series of CPE were investigated by rheological techniques. The studied water soluble polymers showed different rheological behavior depending on their structure (hydrophobe type and content) as well as salinity and pH. The high shear thinning and the formation of networks at low shear would likely promote the use of such polymers in enhanced oil recovery applications.     

New functional inorganic polymers containing phosphorus

The C=C bond plays numerous roles in polymer science. This moiety is used as a precursor to polymers by addition polymerization and has been incorporated into π-conjugated polymers. The addition polymerization reaction has been extended to P=C bonds and the first example of a poly(methylenephosphine) has been prepared. The new macromolecule is of moderate molecular weight (ca. 10⁴ g/mol) and the oxidized polymers are air-stable. Poly(p-phenylenephosphaalkene), the first π-conjugated polymer containing P=C bonds in the backbone, has been prepared. The UV/Vis spectrum of this polymer shows a red shift in λ_max when compared with molecular model systems.     

Theoretical and experimental research on the self‐assembled system of molecularly imprinted polymers formed by salbutamol and methacrylic acid

The quantum chemical method was applied for screening functional monomers in the rational design of salbutamol‐imprinted polymers. Salbutamol was the template molecule, and methacrylic acid was the single functional monomer. The LC‐WPBE/6–31G(d,p) method was used to investigate the geometry optimization, active sites, natural bond orbital charges, binding energies of the imprinted molecule, and solvation energy. The mechanism of action between salbutamol and methacrylic acid was also discussed. The theoretical results show that salbutamol interacts with functional monomers by hydrogen bonds, and the salbutamol‐imprinted polymers with a ratio of 1:4 (salbutamol/methacrylic acid) in acetonitrile had the highest stability. The salbutamol‐imprinted polymers were prepared by precipitation polymerization. The experimental results indicated that the maximum adsorption capacity for salbutamol toward molecularly imprinted polymers was 7.33 mg/g, and the molecularly imprinted polymers had a higher selectivity for salbutamol than for norepinephrine and terbutaline sulfate. Herein, the studies can provide theoretical and experimental references for the salbutamol molecular imprinted system.     

Preparation and reactivity of metal-containing monomers

The radical-induced copolymerization ofmeso-tetraphenylporphyrin monomers with the vinyl group in a benzene or pyrrole ring and their copper and zinc complexes with styrene and methyl methacrylate was studied. Porphyrin comonomers decrease the overall polymerization rate and the number-average molecular weight of the products formed compared to the weight of polystyrene obtained under similar conditions. The main reasons for termination of chain growth by vinylporphyrins were revealed, and some quantitative parameters of these reactions were obtained. IR and electronic absorption spectra of porphyrin-containing copolymers are discussed. According to the ESR spectra, the copper-containing centers in the copolymers are fairly remote from each other, and the metal-containing polymeric systems are magnetically dilute.For Part 45. seeIzv. Akad. Nauk, Ser. Khim., 1995, 2404 [Russ. Chem. Bull., 1995,44, 1758 (Engl. Transl. .)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2922–2929, December, 1996.     

Synthesis and characterization of N-substituted 1,4,5,6-tetrahydropyrimidine containing functional polymers as SO2 and CO2 sorbents

Novel vinyl monomers containing 1,4,5,6-tetrahydropyrimidine were prepared by the reaction of N-substituted-1,3-diaminopropane with N,N-dimethyl-formamide dimethylacetal, which gave 1-alkyl or aryl substituted 1,4,5,6-tetrahydropyrimidines, Alkylation of the tetrahydropyrimidine derivatives by chloromethylstyrene produces the N-methyl-N′-vinyl benzyl-1,4,5,6-tetrahydropyrimidinium chloride in high yields. These monomers were readily polymerized in dimethylformamide by AIBN at 80°C. Homopolymers and soluble linear copolymers were prepared and copolymerization parameters were rationalized. Further, insoluble terpolymers prepared from these monomers, styrene and divinylbenzene were tested for the sorption of the weakly acidic gases gave excellent results. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2411–2420, 1997     

Phase behaviour of lyotropic liquid crystalline side chain polymers in aqueous solutions

Amphiphilic lyotropic liquid crystalline surfactants are synthesized displaying 10-undecenoic acid as hydrophobic and ethyleneglycol units as hydrophilic parts of the molecules. By addition reaction of the monomeric surfactants with poly [oxy(methylsilylene)], the surfactants are attached as side chains to the siloxane main chain. The phase behaviour of a polymer-water system and the corresponding monomer-water system is investigated by polarizing microscopy. The monomeric surfactant exhibits a liquid crystallineM ₁-phase of hexagonally packed, rod-like micelles in a concentration range of 49 to 70% surfactant. The liquid crystalline state of the polymeric surfactant is more stable, which is indicated by a broader temperature- and concentration range (35%–90% polymer surfactant). At lower concentration aM ₁-phase exists, which is separated by a cubic phase from a lamellarG-phase at higher concentration of the polymer surfactant. Compared to the monomeric system, the increased stability of the polymeric mesophase can be understood by the restriction of motions of the amphiphiles due to the linkage to the polymer main chain.Dedicated to Prof. Dr. F. H. Müller.The authors are greatly indebted to Wacker Chemie, D-Burghausen, FRG for kindly delivering the poly(hydrogensiloxane).     

Accurate prediction of thermodynamic properties of alkyl peroxides by combining density functional theory calculation with least-square calibration

Owing to the significance in kinetic modeling of the oxidation and combustion mechanisms of hydrocarbons, a fast and relatively accurate method was developed for the prediction of Delta(f)H(298)(o) of alkyl peroxides. By this method, a raw Delta(f)H(298)(o) value was calculated from the optimized geometry and vibration frequencies at B3LYP/6-31G(d,p) level and then an accurate Delta(f)H(298)(o) value was obtained by a least-square procedure. The least-square procedure is a six-parameter linear equation and is validated by a leave-one out technique, giving a cross-validation squared correlation coefficient q(2) of 0.97 and a squared correlation coefficient of 0.98 for the final model. Calculated results demonstrated that the least-square calibration leads to a remarkable reduction of error and to the accurate Delta(f)H(298)(o) values within the chemical accuracy of 8 kJ mol(-1) except (CH(3))(2)CHCH(2)CH(2)CH(2)OOH which has an error of 8.69 kJ mol(-1). Comparison of the results by CBS-Q, CBS-QB3, G2, and G3 revealed that B3LYP/6-31G(d,p) in combination with a least-square calibration is reliable in the accurate prediction of the standard enthalpies of formation for alkyl peroxides. Standard entropies at 298 K and heat capacities in the temperature range of 300-1500 K for alkyl peroxides were also calculated using the rigid rotor-harmonic oscillator approximation.     

Accessible new acrylic monomers and polymers as highly transparent organic materials

Theoretical studies of intrinsic absorption phenomena in organic compounds in a range of wavelengths from visible to near-infrared (NIR), led us to synthesize acrylic monomers with variable molar number of CH per cubic centimeter, N_CH. Thus, halogenoalkyl or aryl α-chloroacrylates, α-fluoroacrylates, and methacrylates are prepared. The corresponding homo- and copolymers exhibit good thermal (T_g from 120 to 160°C) and optical properties.