Transport of water and methanol vapors in alkyl substituted poly(norbornene)

This report examines the ability of aliphatic-substituted polynorbornenes to separate methanol vapor from water-wet air streams. Single component transport properties of water and methanol were measured for each candidate polymer at 30 °C. The diffusion coefficient, sorption coefficient, and permeability were determined by measuring the rate of mass gain or loss of a sample due to sorption or desorption. The ratio of the permeabilities of the pure components yielded the ideal selectivity. The materials studied in this were methyl-, nbutyl-, nhexyl-, and ndecyl-polynorbornene. These polymers were glassy, with T_gs of 150-380 °C, and have relatively high fractional free volumes (16-19%). The results of the study showed polynorbornenes were methanol selectivity with ideal selectivities of 1.2-9. This permeation selectivity is due primarily to the solubility selectivity of the materials.     

Poly(benzimidazole) and substituted poly(benzimidazoles): Novel,electroactive, and conducting polymers possessing high catalytic and coordination properties

Benzimidazoles and substituted benzimidazoles were electropolymerized on a Pt electrode using acetonitrile containing 0.1 MNaClO₄. The polymers are electroactive and conducting. They have a high electrocatalytic effect on the reduction of H⁺, O₂, and CO₂ and exhibit high coordination ability. The properties of the polymers depend on the extent of conjugation in the monomer. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 112–115, 2000     

Synthesis and properties of alkyl‐substituted poly(1,4‐phenylenevinylene) derivatives

The luminescent poly(2‐dodecyl‐5‐methyl‐1,4‐phenylenevinylene) was synthesized with a new synthetic route. The structure and properties of the polymers were characterized by IR, UV‐vis, luminescent spectra, GPC, and both thermal and elemental analysis. The glass‐transition temperature increases and the photoluminescent relative quantum yield decreases with the increase of the conjugation extent of the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1299–1304, 2001     

Ultraviolet irradiation of poly(alkyl acrylates) and poly(alkyl methacrylates)

Acrylic and methacrylic homopolymers containing different side groups were irradiated with ultraviolet light in the presence of air. The changes of molecular weight distributions of the irradiated polymers were analyzed by means of gel permeation chromatography (GPC), and the rates of chain scission and crosslinking were estimated. As the result of this study, it was found that chain scission takes place more easily in polyalkyl methacrylates than in polyalkyl acrylates.     

Synthesis and chemical modification of new luminescent substituted poly(p-phenylene) polymers

A new acyl-functionalized poly(p-phenylene) (Ac-PPP) was synthesized by Yamamoto cross-coupling and chemically modified to obtain an anthracene-containing derivative (An-PPP). The chemical structures of the polymers were confirmed by ¹H-NMR, ¹³C-NMR, and FTIR spectroscopic analysis. They are fully soluble in common organic solvents and have number-average molecular weight of 2.70 × 10³ and 5.26 × 10³ g mol⁻¹ for Ac-PPP and An-PPP, respectively. The optical properties of the polymers were investigated by UV–visible absorption and photoluminescence spectroscopies. A green emission was observed in Ac-PPP solid thin film and a yellow one in the anthracene-containing polymer An-PPP. The optical bandgap values were 3.21 and 3.08 eV for Ac-PPP and An-PPP, respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The effect of co-dopants on the processability of intrinsically conducting polymers

Using a combination of functionalized dopants was found to be a simple method to improve the processability of intrinsically conducting polymers while retaining relatively high levels of conductivity. Two intrinsically conducting polymers, poly(3-octylthiophene) and polyaniline were co-doped with various combinations of dopants. In both systems, solubility was improved and coherent films were formed directly from common organic solvents without the need for a post-processing doping step. Co-doped intrinsically conducting polymer films exhibited conductivities up to 10^?2 S/cm. Additionally, certain polyaniline complexes were capable of being melt processed without loss of conductivity.     

Antibacterial effect of thiocyanate substituted poly(vinyl chloride)

Poly(vinyl chloride) (PVC) modified in different solvents by nucleophilic substitution with thiocyanate was exposed to Gram-negative bacteria of the strain Staphylococcus capitis. All modified pieces reduced the adhesion of bacteria by between 67 and 79%. More important for the bacteria suppression than the substitution rate was the ratio between thiocyanate and isothiocyanate groups. The best result was obtained with PVC modified in tetrahydrofuran/dimethylsulfoxide, containing only antibacterial active isothiocyanate groups, while inactive thiocyanate groups were absent.     

新型光敏聚合物氯代聚肉桂酰胺酮的合成研究

以肉桂酸为原料合成新型含??不饱和酮结构的光敏单体.然后在无水AlCl3、NMP及DCE的存在条件下,将新合成的单体与2,5-二氯对苯二甲酰氯(DCC)进行低温付一克缩聚反应,合成得到一类新型光敏性聚合物材料--氯取代聚肉桂酰胺酮(C-PAMIK).对缩聚反应的工艺条件进行了优化,并初步表征了所得聚合物.     

Chemical stability of some poly(amide imide) type polymers

The stability of some heterocyclic poly(amide imide)s in acidic and alkaline medium was compared to the structurally related polyimide and poly(amide imide)s without other heterocyclic groups. All the polymers have high stability in acidic medium. The introduction of additional heterocycles such as 1,3,4-0xadiazole or phenylquinoxaline into the macromolecular chain of a poly(amide imide) increases substantially the resistance to alkaline medium. Polyamides containing imide rings only in the side chain are more stable to hydrolysis than related polyamide having imide units in the main chain.     

Benzotrifluoromethyl group‐substituted poly(para‐phenylenevinylene): Effect on solubility,optical, and electronic properties

A new organosoluble benzotrifluoromethyl group containing poly(p‐phenylenevinylene) (BTFM‐PPV) has been synthesized via Gilch polymerization. The polymer is soluble in common organic solvents such as tetrahydrofuran, chloroform, dichloromethane, toluene, and xylene. BTFM‐PPV exhibited fluorescence emission peak with a very high blue shift at 474 nm with an excitation wavelength at 420 nm compared with many other PPV derivatives reported earlier. Incorporation of fluorated bezotrifluoromethyl pendent group in the PPV backbone lowers the HOMO and LUMO energy levels of BTFM‐PPV (2.48 eV) which retarded the hole injection and increase the electron injection in the device. The current–voltage (I–V) characteristic of the polymer was measured by fabricating the polymer as ITO/BTFM‐PPV/Al diode. The device performance was markedly improved by incorporation of 4‐fluoro‐3trifluoromethylphenyl units into the polymer main chain. The turn on voltage of the device observed from the I–V measurements was 7 V. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of a novel alkoxy substituted gold(III) phthalocyanine

Gold(III) compounds have long been investigated for anti-cancer treatment. However, clinical use has often been hampered by their poor stability in solution. In the design of physiologically stable anticancer gold (III) complexes, promising tetrapyrrole derivatives such as phthalocyanines are rarely studied. In this work, a novel soluble symmetrical gold-(III) phthalocyanine (AuPc) complex bearing four pentyloxy terminal moieties was prepared from metal-free phthalocyanine precursor in dioxane in the presence of K[AuCl₄] and sodium acetate/acetic acid buffer. The new gold(III) complex obtained from this metallation was characterized by using elemental analyses, UV–Vis, FTIR, ¹H NMR and mass spectroscopic data. The aggregative properties of the novel compound were also investigated in a concentration range of 2 × 10^− 6 M to 3.1 × 10^− 5 M and no aggregation was observed.     

Exploring the effect of alkyl end group on poly(L-lactide) oligo-esters. Synthesis and characterization

Poly(L-lactide) (PLLA) oligo-esters with α-hydroxyl-ω-alkyl (alkyl = −CH₂−[CH₂−CH₂]_m−CH₃, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10) end groups were synthesized by ring-opening polymerization of L-lactide (L-LA) catalyzed by tin(II) 2-ethylhexanoate Sn(Oct)₂ in the presence of aliphatic alcohols as initiators (HO−CH₂−[CH₂−CH₂]_m−CH₃, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10). High yields (~ 62 to 71%) and M _n(NMR) in the range of 2120–2450 Da (PLLA) were obtained. Effects of alkyl end groups on thermal properties of the oligo-esters were analyzed by DSC, TGA and SAXS. Glass transition temperature (T _g) gradually decreases with increase in the percent of−CH₂−[CH₂−CH₂]_m−CH₃ end group, as results alkyl end group provides most flexibility to PLLA. An important effect of alkyl end group on a double cold crystallization (T _c1 and T _c2) was observed, and is directly related with the segregation phase between alkyl end group and PLLA. TGA analysis revealed that PLLA oligo-esters are more thermally stable with docosyl (−C₂₂H₄₅) respect to the butyl (−C₄H₉) end group, probably is due to steric hindrance of the end group (docosyl respect to butyl) toward intermolecular and intramolecular transesterification. SAXS analysis showed that alkyl end group as docosyl restricted the growth of lamellae thickness (D) due to steric hindrance. Characterization of hydroxyl and alkyl end groups in the PLLA oligo-esters was determined by MALDI-TOF, GPC, FT-IR and ¹ H and ¹³ C NMR.     

The effect of ion-polymer binding on ionic diffusion in dicarbazole-based conducting polymers

An electrochemical polymerization and characterization is reported on a series of eight dicarbazole-type conducting polymers with different attached functional groups. The influence of the electronic character of the subgroup on the ionic conductivity properties of the polymers was examined. Impedance spectroscopy measurements were used to set the ionic chemical diffusion coefficients, D, in the polymer matrix at a variety of doping levels, for each of the polydicarbazoles. We relate D dependency with potential to morphological and electronic processes in the polymer occurring during oxidation. By combination of cyclic voltammetry and impedance spectroscopy for part of the series we reveal that the diffusion of ions in the matrix is easier in polymers were the functional group is highly electron-attracting.     

Substituent effect on the optoelectronic properties of poly(p‐phenylenevinylene) based conjugated‐nonconjugated copolymers

Two classes of light emitting Poly(p‐phenylenevinylene) (PPV) based conjugated‐nonconjugated copolymers (CNCPs) have been synthesized. The conjugated chromophores containing 2‐methoxy‐5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene (MEHPV) and 2,5‐dimethyl‐1,4‐phenylenevinylene (DMPV) moieties are rigid segments and nonconjugated portion containing hexyl units are flexible in nature. All copolymers were synthesized by well‐known Wittig reaction between the appropriate bisphosphonium salts and the dialdehyde monomers. The resulting polymers were found to be readily soluble in common organic solvents like chloroform, THF and chlorobenzene. The effect of chromophore substituents on the optical and redox properties of the copolymers has been investigated. Color tuning was carried out by varying the molar percentage of the comonomers. The UV‐Vis absorption and PL emission of the copolymers were in the range 314–395 nm and 494–536 nm respectively. All the polymers show good thermal stability. Polymer light‐emitting diodes (PLEDs) were fabricated in ITO/PEDOT:PSS/emitting polymer/cathode configurations of selected polymers using double‐layer, LiF/Al cathode structure. The emission maxima of the polymers were around 499–536 nm, which is a blue‐green part of the color spectrum. The threshold voltages of the EL polymers were in the range of 5.4–6.2 V. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of branched alkyl groups on physical properties in poly(ethylene-co-branched alkyl methacrylate)s

Summary Poly(ethylene-co-5.4 mol% n-alkyl/branched alkyl methacrylate)s (PEM) were prepared by a dehydrogenchloride reaction of poly(ethylene-co-5.4 mol% alkyl methacrylic chloride) with the corresponding alkyl alcohol to investigate effect of branching structure and length of alkyl ester on a few physical properties of PEM [glass transition temperature (T_g), degree of crystallinity in polyethylene region (X_c) and dielectric molecular motion], where the alkyl groups used here are n-propyl, n-butyl, n-hexyl, n-decyl, 2-ethylhexyl, 3,5,5-trimethylhexyl and 2-(1,3,3-trimethylbutyl)-5,7,7-trimethyloctyl. In the n-alkyl methacrylate copolymers, T_g and X_c were almost unchanged with the presence of alkyl ester, but T_g increased and X_c decreased in the highly branched alkyl methacrylate copolymers even at the low methacrylate content of 5.4 mol%.     

Graft copolymers of poly(methyl methacrylate) backbone and poly(propylene oxide-b-ethylene oxide) branches

Summary Two mono-functional macromonomers of poly (propylene oxide-b-ethylene oxide) were synthesized by reaction with methacryloyl chloride. The macromonomers have the same molecular weight and ratio of ethylene oxide and propylene oxide sequences. The reactive methacrylate group can be linked to the ethylene oxide (BuPPOPEO) or to the propylene oxide (BuPEOPPO). These macromonomers showed self-gelling in one week even at low temperature and under a dry atmosphere. Graft copolymers were obtained by reaction of these macromonomers with methyl methacrylate upon free-radical initiation and they were characterized by GPC, VPO, IR and ¹H NMR spectra.     

The effect of added salt on the flow of highly dilute solutions of poly(ethylene oxide) polymers

Early transition, early turbulence, and drag reduction were detected in flowing solutions of high molecular weight poly(ethylene oxide) condensates. Progressive addition of salt (magnesium sulfate) increased the onset point characterizing deviations from Newtonian flow for 1 ppm Polyox Coagulant solutions and eliminated early transition in the 10 ppm WSR-35 solutions. No further drag reduction was observed when the salt molarity reached the 0.65 level. In the Coagulant solutions the onset wall shear stress characterizing the flow deviation was an inverse function of the intrinsic viscosity of the polymer in the salt solution.     

New copolymer of poly(N‐vinylcarbazole) and poly(p‐phenylenevinylene) for optoelectronic devices

A novel diblock copolymer based on poly(N‐vinylcarbazole) PVK and poly(p‐phenylenevinylene) (PPV) precursor was synthesized by oxidative cross‐linking. The grafting of PPV with PVK moieties was elucidated by infrared absorption analysis. A structural study by X‐ray diffraction and a morphological study of the copolymer by scanning and transmission electron microscopy reveal a multiscale one‐dimensional self‐organization both at the molecular and at the sub‐micrometric level. The resulting copolymer exhibits original optical properties compared to those of PVK and PPV ones and presents an improved thermal behavior. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2839–2847, 2013     

Studies on semiinterpenetrating polymer networks based on poly(vinyl chloride-co-vinyl acetate) and poly(alkyl methacrylates)

A number of semi-interpenetrating polymer networks (IPNs) based on linear poly(vinyl chloride-co-vinyl acetate) and poly(alkyl methacrylates) were synthesized. The semi-IPNs were found to be transparent, high strength materials. The IPNs show only one glass-transition temperature and it is dependent on the composition as studied by differential scanning calorimetry and dynamic mechanical analysis. These IPNs are also characterized by high tan δ values. The tensile strength of the IPNs were found to be higher compared to the starting polymers. In order to compare the properties of these IPNs with the corresponding homopolymers and blends, the latter were synthesized and the properties were studied. © 1994 John Wiley & Sons, Inc.