Asymmetric interaction of optically active polymers with asymmetric small molecules. IV. Effect of hydrophobic groups on asymmetric interaction

In order to investigate the mechanism of the asymmetric interaction between optically active polymers and small molecules, optically active copolymers of N-acrylyl L-amino acids(N-acrylyl-L -phenylalanine, N-acrylyl-L -tryptophan, and N-acrylyl-L -leucine, respectively) and N,N′-hexamethylene diacrylylamide were synthesized, and interaction of these polymers with the optical isomers of phenylalanine and tryptophan was investigated. In the interaction of these acidic polymers with amino acids performed at pH 5.0, significant difference in amount of adsorption between the D and L isomers of amino acids were observed, and the L form of amino acids was adsorbed preferentially. The interaction between optically active small molecules was also investigated: these results showed a similarity to the results for interaction between optically active polymers and amino acids. In some instances of asymmetric interaction the influence of hydrophobic interaction between a polymer and substrate was clearly perceived. The stereoselective effects on the asymmetric interaction are discussed.     

Functional monomers and polymers. XXXXI. Template polymerization of methacryloyl-type monomers containing nucleic acid bases

In due consideration of the specific base–base interaction that exists between nucleic acid molecules, the free radical polymerization of N-β-methacryloyloxyethyl derivatives of adenine, thymine, and theophylline initiated by azobisisobutyronitrile (AIBN) was studied in the presence of N-β-methacryloyloxyethyl-type polymers which have complementary nucleic acid bases as template polymers. The rate of polymerization of N-β-methacryloyloxyethyladenine was accelerated when poly(N-β-methacryloyloxyethyluracil) or -thymine was present in the polymerization system. The effect of the stereoregularity of the template polymers, as well as polymerization temperature and the sort of solvents used on the rate of polymerization, was studied and discussed in some detail. The results suggest that the interaction between complementary bases plays a role in template polymerization behavior.     

A novel method for the synthesis of liquid crystalline polymers. Preparation by the interaction of poly(acryloyl chloride) with mesogenic compounds

A new method for the synthesis of thermotropic liquid crystalline polymers, which is comprised of the interaction of reactive polymers with mesogenic compounds, was investigated. This method is illustrated by the interaction of poly(acryloyl chloride) with p-hydroxybenzylidene-p-butylaniline or p-aminobiphenyl on the preparation of poly(p-acryloyloxybenzylidene-p-butylaniline and poly(N-p-biphenylacrylamide)), respectively. These polymers were subjected to characterization studies which included optical microscopy, x-ray diffraction analysis, and differential scanning calorimetry. It was established that both polymers in the melt exhibit smectic mesomorphism.     

Light scattering characterization of thermodynamic interaction of polymers in dilute solution. Effect of solvent and molecular weight

Interaction of nonidentical polymer molecules in a dilute solution of a mixture of two polymers is quantitatively characterized by A₂₄, the second virial coefficient for interaction of unlike species. This parameter is related to the compatibility of the two polymers in solution and is obtainable experimentally, e.g., by light scattering. With chemically markedly different polymers, A₂₄ depends neither on the molecular weight of the polymers nor on the solvent and becomes characteristic of the polymer pair. For a mixture of two copolymers or of a homopolymer and a copolymer with similar compositions, A₂₄ depends both on the solvent and on the molecular weight of polymers. Under such circumstances A₂₄ ceases to be a quantity given only by the chemical structure of the two polymers; however, under suitable conditions it remains a sensitive function of the difference between the chemical nature of polymer components.     

Arylidene Polymers. IX. Synthesis,Characterization, and Morphology of New Polyesters of Diarylidenecycloalkanones Containing Thianthrene Units

New polyesters containing thianthrene tetraoxide were synthesized by the interaction of 2,7-dichloroformylthianthrene-5,5′,10, 10′-tetraoxide with 2,5-bis(p-hydroxybenzylidene)cyclopentanone, 2,5-divanillylidenecyclopentanone, 2,6-bis(p-hydroxybenzyiidene)-cyclohexanone, 2,6-divanillylidenecyclohexanone, and 2,7-bis(p-hydroxybenzylidene)cycloheptanone by using the interfacial polycondensation technique. The resulting polyesters were characterized by elemental and spectral analyses. All the synthesized polymers readily dissolved at room temperature in dimethylsulfoxide. The thermal properties of the polymers were evaluated and correlated to their structural units by TGA and DSC measurements. X-ray analysis of polymers showed that all the polyesters are amorphous. Moreover, the morphology of a new high performance polyester, poly[oxycarbonyl-2,7-thianthrene-5,5′,10,10′-tetraox-idecarbonzeoxyl(2-methoxy-p-phenylene)methylidyne(2-oxo-1,3-cyclohexanediylidenemethylidyne)methylidene(3-methoxy-p-phenylene)], has been investigated by scanning electron microscopy.     

Polymer containing fluorinated ketone groups. I. DSC and NMR studies of poly(p-vinyltrifluoroacetophenone) and polymers of similar structure

The unexpected crystallinity of free radically polymerized poly(p-vinyltrifluoroacetophenone) (PVTFA) due to lateral order was previously found in this laboratory. To further the understanding of the relationship between chemical structure and crystalline order in polymers of the PVTFA type, polymers of similar structure were synthesized and characterized by differential scanning calorimetry (DSC). These polymers were poly(p-vinyldifluoroacetophenone) (PVDFA), poly(p-vinylphenylheptafluoropropyl ketone) (PVHFK), poly(p-vinylacetophenone) (PVA), and poly(p-vinylphenyltrifluoromethyl carbinol) (PVPTC). Only PVTFA had a crystalline melting temperature (188°C); 220-MHz nuclear magnetic resonance (NMR) measurements on the microstructure of PVTFA and PVDFA revealed broad peaks for the chain protons. The PVTFA was therefore assumed to be predominantly atactic. The results suggested that the unusual crystallinity of PVTFA was related to the unique size and interaction of the trifluoroacetyl moiety on the polymeric side chain.     

Quaternary Ammonium Polyelectrolytes. V. Amination Studies of Chloromethylated Polystyrene with N,N-Dimethylalkylamines

The amination reactions of chloromethylated polystyrene with N,N-dimethyldodecylamine, N,N-dimethyltetradecylamine, and N,N-dimethylhexadecylamine were studied. The physical properties, particularly the solubility properties of the resulting polymers, are influenced by the hydrophobic properties of the long alkyl chain on the N⁺ atoms. The main factor that influences the kinetics of the reactions is the polymersolvent interaction parameter.     

Functional monomers and polymers. XXXXVII. Complex formation of stereoregular methacryloyl-type polymers containing nucleic acid bases

The complex formation between a poly(N-β-methacryloyloxyethyl) derivative of adenine with one of thymine or uracil was studied in dimethyl sulfoxide and ethylene glycol mixture by ultraviolet (UV) spectroscopy. For the polymer pairs containing complementary nucleic acid bases both hypochromicity and hyperchromicity were found. Stereoregularity of the polymers, as well as the conditions for measurement of, for example, solvent, temperature, and time, affected the complex formation. Both inter- and intramolecular interaction of polymers in solution were discussed in some detail.     

Conformational properties of polar polymers. I. Poly(vinyl chloride)

A recently developed method for including polar bonds in conformational energy calculations is applied to poly(vinyl chloride). Inductive effects on dipole moments and the effects of intervening atoms on electrostatic interaction energies are represented by polarizability centers in conjunction with bond centered dipoles. Solvation energies are estimated by means of a continuum dipole–quadrupole electrostatic model. Calculated energies of a number of conformations of meso and racemic 2,4-dichloropentane and the iso, syndio, and hetero forms of 2,4,6-trichloroheptane give satisfactory representations of isomer and conformer populations. Electrostatic effects are found to be quite important. However they appear to be effectively of sufficiently short range that the calculated conformer energies are found to be fit well by a linear combination of interaction parameters (consisting of gauche, skew chlorine, four-bond CH₂…CH₂, CH₂…Cl, and Cl…Cl interactions) conventional to vinyl polymers and a special four-bond interaction that arises when the bond sequence Cl? CH? CH²? CH? Cl is (nearly) coplanar. These interaction parameters when assembled into statistical weight matrices lead to calculated values of both the characteristic ratio and the dipole moment ratio in satisfactory agreement with experiment. Least energy paths for transitions between the most stable conformations are also calculated.     

Poly(silmethylene)-based polymer blends. I. In situ polymerization of 1,3-disilacyclobutanes in silicon-based polymers

The in situ polymerization of 1,1,3,3-tetraphenyl-1,3-disilacyclobutane with or without a catalyst in flexible organo-silicon polymers was demonstrated to provide poly(silmethylene)-based polymer blends. An alternative route, which implies preparation of blends via synthesis of a flexible polymer in the presence of a rigid polymer, was also promising. The resulting polymer blends were characterized by DSC, dynamic mechanical analysis, and solvent extraction. No chemical interaction is observed between component polymers of blends prepared by the in situ bulk polymerization method while formation of block or graft copolymers comprising poly(diphenylsilmethylene) and flexible polymers is suggested when in situ copper-catalyzed polymerization was employed. A morphological difference between samples synthesized by the different methods was suggested by microscopic observation. © 1997 John Wiley & Sons, Inc.     

Incompatibility of polymer solutions. III. Critical opalescence in the system polystyrene + polyisobutylene + toluene

The angular dependence of light scattering from the homogeneous ternary system polystyrene + polyisobutylene + toluene was measured at a fixed (critical) concentration as a function of temperature. On approaching the critical temperature the scattering becomes very large and strongly angle-dependent. The experiments show that the interaction range r_G is of the same order of magnitude as the molecular radius of gyration of the polymer, but cannot be set equal to it as in the case of a binary system of one polymer in a single solvent. The temperature dependence of the various interaction parameters does not depend on the molecular weights of the polymers.     

Developments in antimicrobial polymers

Effective antimicrobial polymers have been attracting more interests because of the low propensity to cause drug-resistant microorganisms. The recent progresses in antimicrobial polymers are updated according to the action approaches, that is, antimicrobial polymers with free mobility or fixed on surfaces, respectively. Free antimicrobial polymers kill pathogens majorly via electrostatic interaction followed by disruption of the cell membranes; strong antimicrobial activity of primary/secondary amines, new chemical units, and peptides without facial amphiphilicity are highlighted; and the dependences on amphiphilicity, topology, and self-assembly profiles are summarized. Antimicrobial polymers fixed on surfaces kill pathogens via interaction with the cell membranes of pathogens via electrostatic or hydrophobic interaction; approaches to antimicrobial surfaces based on covalently grafting, anchoring, and bulk-mixing of polymers are summarized; and new designs of sustainable antimicrobial surfaces and hydrogels are highlighted. Deep biology understanding and development strategies of materials are suggested for the future. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 632–639     

Indirect Measurement of the Cooperative Hydrogen Bonding of Polymers Using NMR Quadrupole Relaxation and PFG Methods

Summary: A general method of measurement of polymer hydrogen bond (HB) cooperativity using a low-molecular weight model ligand named marker and two independent methods of ²H NMR is presented. As marker, a deutero-compound chemically similar to the functional groups of one of the polymers is used, e.g. pyridine-d₅ in the investigated interaction of poly(4-vinylpyridine) with poly(4-vinylphenol) or acetic acid-d₄ in the interaction of polyacrylic acid with poly(4-vinylphenol) reported here. The method is based on the fact that a substantial fraction of the marker, originally bound to the groups of one of the polymers, is liberated by the cooperative interaction between the two polymers. For the establishment of the fraction of the bound marker before and after mixing the polymers, ²H NMR quadrupolar relaxation or ²H PFG NMR diffusion measurement can be used with comparable precision. In both these methods, the results must be normalized to a standard viscosity using the relaxation or diffusion of an added inert compound such as CDCl₃.     

Vinyl monomers bearing chromophore moieties and their polymers. XI. Synthesis and photochemical behavior of carbazole‐containing methacrylic monomers and their polymers

Three carbazole‐containing methacrylic monomers, 2‐(N‐carbazolyl)ethyl methacrylate(CzEMA), 6‐(N‐carbazolyl)hexyl methacrylate(CzHMA), and 11‐(N‐carbazolyl)undecyl methacrylate (CzUMA), and their saturated model compounds, 2‐(N‐carbazolyl)ethyl isobutyrate, 6‐(N‐carbazolyl)hexyl isobutyrate, and 11‐(N‐carbazolyl)undecyl isobutyrate, were synthesized and polymerized. UV absorption spectra showed that there was either negligible or no interaction between the carbon–carbon double bond of the methacrylic group and the carbazolyl chromophore moiety in the ground state for these monomers. Fluorescence spectra of the monomers, their model compounds, and the polymers were recorded in the solvents with different polarities. CzEMA exhibited the fluorescence structural self‐quenching effect (SSQE), but CzHMA and CzUMA did not. In addition, the SSQE of CzEMA depended strongly on the polarity of the solvents. That is, the stronger the polarity of a solvent was, the more obvious the SSQE was. Therefore, the SSQE of CzEMA mainly was caused by the intramolecular charge‐transfer interaction between the excited electron‐donating carbazolyl chromophore moiety and the electron‐accepting carbon–carbon double bond of the methacrylic group. This was confirmed by the fluorescence‐decay curves and the fluorescence lifetimes of the monomers, their model compounds, and the polymers. The monomers, their model compounds, and the polymers initiated the photopolymerization of methyl methacrylate (MMA) upon UV irradiation. CzEMA showed greater initiation ability than the other two monomers and their model compounds; this was ascribed to the photoinduced intramolecular charge‐transfer interaction. The higher initiation efficiency of the homopolymers compared to that of the copolymers with MMA was interpreted as the result of singlet energy migration of the excited carbazolyl chromophores along the polymer chains. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 679–688, 2000     

Relaxation and Miscibility of the Blends of a Poly (Ether Imide) (Ultem™) and a Phenol-A-Based Copolyester (Ardel™) by Inverse Gas Chromatography

Inverse gas chromatography (IGC) was used to analyze the secondary transition temperatures and the miscibility of binary mixtures of poly (ether imide) (Ultem™) and a copolyester of bisphenol-A with terephthalic and isophthalic acids (50/50) (Ardel™) in three compositions (25/50, 50/50 and 75/25). Retention diagrams of the mixtures of Ultem™ and Ardel™ for n-nonane, n-decane, n-butyl acetate and isoamyl acetate were obtained at temperatures between 60 and 285 °C. Second-order transition temperatures of the mixtures were determined according to the slope change in retention diagrams of the solvents. The glass transition temperatures of the mixtures suggested the miscibility of the polymers. Polymer–polymer interaction parameters of binary mixtures of the polymers were determined at temperatures between 260 and 285 °C by Flory–Huggins theory. The polymer–polymer interaction parameters were dependent on the solvent used. The small values of polymer–polymer interaction parameters close to zero suggest some weak interactions between the polymers in the mixture. It was concluded that it was possible to obtain more meaningful information related to the interactions of polymers in a mixture from IGC measurements, if binary polymer–solvent interaction parameters of the used solvent probes were around 0.5.

     

Novel nonionic surfactants based on sulfoxides. 2. Homo- and copolymers

The synthesis of new nonionic amphiphilic polymers of the polysoap type is described, as well as their general behaviour in aqueous solution. The polymers were prepared by homopolymerisation of acrylate polymerisable surfactants (or "surfmers"), which bear the nonionic sulfoxide moiety. Alternatively, small hydrophilic acrylate and acrylamide monomers bearing the nonionic sulfoxide moiety were copolymerised with dodecylacrylate and N-dodecyl- N-methylacrylamide. Compared to many other nonionic hydrophilic fragments, a single sulfoxide group behaves as a strongly hydrophilic fragment of small volume. However, its relative hydrophilicity depends sensitively on its precise positioning in the polymers. Properly placed, three sulfoxide groups can balance up to two dodecyl chains to obtain still water-soluble polymers that exhibit typical polysoap properties. Some of the new nonionic polymers show lyotropic liquid-crystalline behaviour at ambient temperature.     

Self‐Propagating Association of Zwitterionic Polymers Initiated by Ionene Polymers

A self‐propagating association of zwitterionic polymers is observed when a small amount of x,y‐ionene bromide (x = 3 or 6; y = 3, 4, 6, 10 or 12) polymer is added to aqueous solutions of zwitterionic polymer, poly[3‐dimethyl(methacryloyloxyethyl)ammoniumpropanesulfonate] (PDMAPS), to give large amount of PDMAPS precipitate. The self‐propagating association initiated by ionene polymers is explained in terms of the electrostatic interaction between the ionene polymers and the zwitterionic polymers whereupon the geometry of the charges on the polymer chains plays an important role.     

Midgap levels of photoexcited conductive polymers. II. Detailed analysis of trans-polyacetylene

We have studied in more detail aspects of the soliton-antisoliton pair in a trans-polyacetylene chain based on our previous study of the midgap levels associated with the photogenerated oppositely charged soliton-antisoliton pair in conductive polymers employing the concept of the molecular orbital interaction (Part I of this study, this issue). The intersoliton distance has been estimated to be about 10 Å from the Pariser–Parr–Pople method. We have found that the energy gap between the midgap levels is estimated to be 0.45 eV, being significantly related to an additional photoinduced absorption.     

Magnetic circular dichroism studies of aromatic polymers

The magnetic circular dichroism (MCD) spectra of syndiotactic and isotactic polymers which contain aromatic chromophores have been found to be sensitive to configurational and conformational differences. For isotactic polymers it was determined that as the aromatic ring moved farther from the main chain the ration of B terms of the polymers to those of their model compounds reached a minimum but increased significantly when the aromatic ring was separated from the main chain by four atoms. This enhancement of MCD is believed to be caused by the alignment of the more flexible side chains which would allow the interaction of the aromatic rings with neighboring groups and could result in a favorable mixing of the ester electronic transition with the aromatic ¹A_1g?¹B_2u transition. This effect was not felt to any great extent by the syndiotactic polymers because the necessary nearest-neighbor interaction was sterically unfavorable. The ratio of the B terms of isotactic poly(phenyl methacrylate) to its model compound decreased as the polymer coil expanded, whereas it increased for the syndiotactic polymer. This effect reflects the different changes that the side chain interaction and orientations undergo in these polymers during coil expansion. The MCD ratios for iso- and syndiotactic poly(phenylethyl methacrylate) were not so sensitive during coil expansion. The ratio of the dipole strengths of the polymers and model compounds paralleled the MCD results, but the ultraviolet (UV) technique was less sensitive than MCD to subtle conformational differences. Poly(benzyl methacrylate) and benzyl pivalate were unsuitable systems for studying the MCD effect because the B terms of these materials approached zero.     

Solution properties of ultrahigh molecular weight polymers. VII. Conformational characteristics of poly(butyl methacrylate)

The paper is concerned with light scattering studies on solutions of ultrahigh molecular weight poly(butyl methacrylate). The dependence of the radius of gyration and of the second virial coefficient on the weight-average molecular weight of the polymers was established in methyl ethyl ketone, dimethylformamide, and CCl₄. Short-range and long-range interactions were discussed in terms of the steric factor σ, of the interaction parameter B, and of the interpenetration function ψ(z).