The Mechanism of Radiation Destruction of Dyes in Polymers: A New Method for Increasing the Stability of Dyed Polymers Based on Oscillative Cross-Relaxation

Abstract

Discussion of the mechanism of radiation destruction of dyes in polymers, which is associated with solid-phase chemical reaction between dye molecules and oxyradicals appearing either on destruction of polymer molecules or on oxidation of macroradicals by the oxygen dissolved in the matrix. Experimental results are given on radiolysis and photolysis of polymethyl methacrylate with a “resonant” low molecular weight additive and dye (nickel dithiobenzil complex and vanadyl phthalocyanine), which demonstrate the decisive role of oscillative cross-relaxation between macromolecules and molecules of the additive in increasing the radiation stability of dyed polymers.     

Studies on Aminoanthraquinone Compounds VI—Photochemistry of N-Methyl Derivatives on Polymer Films

The effect of (a) short-wave ultraviolet radiation (mainly 253-7 mμ) and (b) near-ultraviolet and visible radiation on polymer films dyed with the two disperse dyes, 1-methylaminoanthraquinone and 1,4-bismethylaminoanthraquinone, has been studied. Dyes on nylon films undergo reduction when exposed in dry nitrogen to 253-7-mμ radiation. The effect of near-ultraviolet and visible radiation is different; in dry nitrogen, 1-methylaminoanthraquinone on N-methoxymethylnylon film is reduced to the same extent as with 253-7-mμ radiation, but on other nylon films (nylon 6, nylon 6.6, and nylon 11) the reduction observed with this dye is much smaller. There is no evidence of reduction of 1,4-bismethylaminoanthraquinone on any of the nylon films. On cellulose acetate film, neither dye is reduced on exposure in dry nitrogen, by either source of radiation. The significance of these results in relation to the photo-sensitised degradation of textile fibres is discussed.     

Thermal and radiation chemical stabilities of some polymers after Cu(II) build-up

The interaction of polyacrylic acid (PAA), polysodium acrylate (PAANa), polyacrylamide (PAM) and acrylic acid–acrylamide copolymer P(AM-AA) with copper sulphate was studied to evaluate the thermal and radiation chemical stabilities of the resultant polymers which contained increasing quantities of Cu^{2 +} . It was found that the efficiency of the polymers toward Cu^{2 +} interaction, as determined by XRF, follows the order P(AM-AA) > PAM > PAANa. PAA was inactive, and no Cu^{2 +} ions were detected. Generally, the results obtained from TGA and DSC reveal that there is an improvement in the thermal stability when Cu^{2 +} is incorporated into the polymer matrix, but the amount of Cu^{2 +} bound to the polymeric chains does not correlate with their relative thermal stability. The degree of crystallinity estimated by X-ray diffraction also increases as Cu^{2 +} is incorporated into the polymer. In addition to the thermal stability, the radiation chemical stability of polymer with accumulated Cu^{2 +} was found to be very high, so that the percentage of Cu^{2 +} released from the crosslinked polymers was zero at radiation doses of up to 500 kGy. © 1999 Society of Chemical Industry     

Silicon‐containing anionic water‐borne polyurethane with covalently bonded reactive dye

A silicon‐containing water‐borne polyurethane (PU) polymer with hydroxyl side groups was synthesized that was stable in basic conditions and also capable of reacting with a reactive dye to form a covalently bonded dye molecule. The silicon‐containing anionic water‐borne PU prepolymer was synthesized from H₁₂‐4,4′‐diphenylmethane diisocyanate (H₁₂‐MDI), polytetramethylene glycol, polydimethylsiloxane (PDMS), 2,2′‐bis(hydroxymethyl), propionic acid (anionic centers), and triethyleneamine using the prepolymer mixing method. Water was then added to emulsify and disperse the resin to form an anionic water‐borne PU prepolymer. N‐(2‐Hydroxyethyl ethylene diamine) (HEDA) was used to extend the prepolymer to form a water‐borne PU polymer with a side chain of hydroxyl groups, which can further react with the reactive dye to form a dyed PU. The reactive dye of chlorosulfuric acid esters of sulfatoethyl sulfones can react with the water‐borne PU polymer. Behaviors of alkali resistance and dyeing properties were observed. In consideration of thermal properties, the dye‐grafted PU polymers exhibited lower glass‐transition temperatures for soft segments and hard segments than those without dye. Concerning mechanical properties, it was found that the modulus and the strength of the dyed PU polymers decreased with grafting of the dye molecule, but elongation at break was increased. The alkali resistance increased with PDMS content. For dye‐uptake properties, the percentage of dye grafting was over 90%. Also, the dye‐grafted PU exhibited a lower percentage of dye migration than that of polymers with ethylene diamine instead of HEDA as a chain extender, and showed greater colorfastness to light. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2045–2052, 2003     

Dyeing of pet textile fibers and films in supercritical carbon dioxide

Polyethylene terephthalate (PET) textile fibers were dyed with a disperse dye in the presence of supercritical carbon dioxide at three temperatures of 333.2, 363.2 and 393.2 K and at pressures between 15 and 25MPa. The PET film was also dyed at 393.2 K. It was found that the dye uptake in the fiber increased 2–5 times when a small amount of acetone was added as a cosolvent. The equilibrium dye uptake increased with increasing pressure at all temperatures. At 393.2 K the pressure effect appeared to be much larger. It was explained with the shift of the glass transition temperature of the polymers at high pressures. These results may be useful in designing and developing the pollution-free supercritical dyeing technique, a potential alternative to the conventional dyeing of polyesters that produces a lot of wastewater.     

Synthesis of a new,yellow crosslinking polyvinylamine dye and its crosslinking/dyeing process through a crosslinker

A new, yellow crosslinking polyvinylamine dye was synthesized by the reaction of 2,4‐dinitrochlorobenzene with polyvinylamine prepared from Hofmann degradation of polyacrylamide. It was crosslinked and dyed to cotton and silk by a crosslinker synthesized from 1,3,5‐trichloro‐s‐triazine and sodium 2‐(p‐aminophenylsulfonyl)ethyl sulfate. The crosslinking/dyeing conditions of the yellow polyvinylamine dye, such as pH, cure temperature, and concentration of the crosslinker were investigated. The fixations of the polymeric dye by the crosslinker on cotton and silk were greater than 99%. The crosslinking covalent dye–fiber bond was proved indirectly by the comparison of IR spectra of the undyed fiber, the dyed fiber, and the crosslinked one, and also by the fact that no dye was stripped off from the crosslinked and dyed sample by extraction with DMF/water (1 : 1). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1568–1573, 2006     

Influence of side chains on electrochromic properties of green donor–acceptor–donor polymers

Three solution processable cathodically coloring green electrochromic polymers, based on 2,3-diphenyl-5,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine, have been synthesized by oxidative FeCl₃ polymerization. The polymers were designed with solubilizing alkyl and oligoethylene oxide side chains to achieve solubility and processability. All three polymers have a small electrochemical bandgap (1.8–1.9 eV) and low oxidation potentials. Spectroelectrochemical studies of polymer films on ITO reveal that the alkyl side chains in head-to-head position on the polymer backbone promote a defined high-energy absorption peak and suppress tailing of charge-carrier absorption into the visible region. Kinetic studies, based on transmission measurements applying a square-wave potential between reduced and oxidized states, show that the polymer with exclusively oligoethylene oxide side chains (P3) had the fastest response times, monitored at the low-energy absorption maxima. The best performing polymer (P1) showed a good optical contrast in the visible region with a ΔT of 26% at 700 nm. An initial test of the electrochemical stability showed that the oligoethylene oxide containing polymers had superior stability over 500 full switches.     

Specific Features of Photodestruction and Photostabilization of Dyed Textile Materials

Abstract

The present paper is a brief review of some basic problems linked with the analysis of lightageing regularities of dyed textile materials. Finished textile materials are as a rule a complicated composition from fibreforming polymers, dyestaffs (or their mixtures) and special preparation giving a set of predetermined consumer properties to the dyed polymer material (finishes). These components have different lightfastness and, besides, can differently influence on lightfastness of each other.     

Photochemical Behaviour of Vat Dyes I—Reaction with the Polymer Substrate

The action of (a) near-ultraviolet and (b) short-wave ultraviolet radiation (mainly 253.7 nm) on nylon 6 and cellulose films dyed with one non-sensitising and two sensitising vat dyes has been studied. Photoreduction (in nitrogen) to the acid leuco derivative of the dye is observed only on exposure to 253.7-nm radiation. Vat dyes desensitise the degradation of cotton by 253.7-nm radiation, but there is no simple relation between this desensitising effect and their sensitising effect with near-ultraviolet and visible radiation. Degradation of vat-dyed cotton by 253.7-nm radiation is not increased by the reduction of the dye to the acid leuco form. Radical formation is unrelated to fibre degradation. The experimental evidence favours the concept of Kautsky's activated oxygen as an intermediary in the photosensitised degradation of cotton by near-ultraviolet and visible radiation, rather than that of hydrogen abstraction.     

Effect of γ‐irradiation on the physical properties and dyeability of poly(vinyl butyral) blends with polystyrene and poly(ethylene glycol)

Cast films of polymer blends essentially based on poly(vinyl butyral) (PVB) and equal ratios of polystyrene (PS) and poly(ethylene glycol) (PEG) were prepared from benzene and butyl alcohol solutions of the individual polymers. The effect of γ‐irradiation on the thermal decomposition and tensile mechanical properties was investigated. Moreover, the effect of γ‐irradiation on the dye affinity of PVB/PS and PVB/PEG for basic and acid dyestuffs was studied. The thermogravimetric analysis (TGA) study showed that the unirradiated PVB polymer films prepared in benzene displayed higher thermal stability than the same polymer films prepared in butanol. However, in all cases the thermal stability was found to increase with increasing γ‐irradiation dose. On the other hand, PVB/PS blend possesses higher thermal stability than PVB/PEG, as shown from the determination of the weight loss (%) at different heating temperatures, the temperatures of the maximum rate of reaction and the activation energy. While, pure PS films showed the stress‐strain behavior of brittle polymers, PVB/PS films showed the behavior of tough polymers with yielding properties. The results of dyeing clearly showed that the solvent type, blend composition, and irradiation dose are determining factors for the dye affinity for basic or acid dyes. For example, unirradiated PVB films prepared from butanol displayed a higher affinity for the basic and acid dyes than the same polymer prepared from the same benzene. However, PVB prepared from butanol showed higher affinity to the dyes than PS prepared from the same solvent. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Poly(ethylene terephtalate) films modified with N,N‐dimethylacrylamide: Incorporation of disperse dye

Poly(ethylene terephtalate), PET, can be modified with N,N‐dimethylacrylamide to obtain a better incorporation of disperse dye (Disperse Blue 79). Minimal variations in the decomposition at 10% level, melting, and glass transition temperatures, show that the thermal stability of modified PET films does not change when compared to nonmodified PET. The atomic force images show nanopeaks formation on the surface due to the modification. Modified PET films show a decrease in the contact angle and then, an increase in the superficial tension measurements, when compared to the value of 37 ± 1 dynes · cm⁻¹(nonmodified), with values liying in the range of 42–46 ± 0.5 dynes · cm⁻¹. The data obtained by photoacoustic spectroscopy (PAS) for dyed PET films show a dye peak at 580 nm. The data analysis of the peak area show that PET films modified with N,N‐dimethylacrylamide for 15 min at 85°C, dyed for 6 h at 85°C with a dye concentration of 0.333 g/L, incorporate three times more dye than the nonmodified films dyed in the same conditions. By the data obtained from PAS, it was possible to calculate the depth profile of dyeing with values around 54 μm. Factorial analyses show that the dyeing time was the most important variable. The major amount of incorporated dye was obtained by the following combination of variables: temperature and time of modifier treatment were, respectively, 72.5°C and 15 min; time and temperature of dyeing were, respectively, 90°C and 195 min for a dye concentration of 0.133 g/L. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 269–282, 2000     

New aroyleneimidazoles as dyes for thermoplastic polymeric materials

New perinone dyes for bulk dyeing synthetic polymers were synthesized. The synthesized dyes are characterized by high thermal stability. The possibility of dyeing Macrolon 28/08 polycarbonate with some of the synthesized dyes was investigated. It was shown that the dyes were uniformly distributed in the bulk of the polymer. It was found that incorporation of a perinone dye containing a pyridine radical in the polycarbonate during formation increases the glass transition temperature, decreases thermooxidative degradation of the polymer, and yields films with elevated physicomechanical indexes. __________ Translated from Khimicheskie Volokna, No. 3, pp. 5–8, May–June, 2006.     

Sulfoalkylation of a polybenzimidazole with propanesultone

Poly-2,2′-(m-phenylene)-5,5′-bisbenzimidazole has been alkylated with propanesultone to yield polymers which are readily dyed with basic dyes. Propanesultone has been used to convert cellulose, starch, phenolformaldehyde resin, and various vinyl copolymers into hydrophilic materials which dye readily or act as ion exchange resins.^1–5 It seemed likely it would react with a polybenzimidazole to make the polymer more water absorptive and readily dyeable with basic dyes. Hence this work was undertaken.     

Poly(urea-urethane) polymers with multi-functional properties

Polyurea-urethanes with multifunctional properties were synthesized by reacting 4,4′-diphenylmethane disocyanate (MDI) with a two diol mixture of polytetramethylene glycol (PTMG (1000, 2000) and biocidal quaternary ammonium monomer ((N-benzyl-N-dodecyl-N-bis2-hydroxyethyl) ammonium chloride (BDAC)), and extended with N-(2-hydroxyethyl) ethylene diamine (HEDA) to form PU polymers. The PU polymer was then grafted with a disperse dye via a coupling agent of epichlorohydrin to form a dye grafted polyurethane with biocidal and covalent bond dyeing properties. In consideration of the mechanical properties, it is found that both the modulus and the strength of the dye grafted PU polymer films are lower than those of pure PU polymers due to the bulkiness of their dye molecules. For thermal properties, the dye grafted PU polymers exhibit higher T_gh than those without dye molecules. However,neither the T_gs nor the T_ms vary in the presence of BDAC or dye molecules, but they are changed with various chain lengths of the soft segment. For dyeing properties, the effective dyeing efficiency of dye grafted PU is over 85%. Moreover, the dye grafted PU polymers exhibit lower dye migration (M_p%) than those of simple mixtures of PU and dyestuff, and they show a higher grade of color fastness when exposed to light. In the shake method of antibacterial testing, the modified PU polymers exhibit a long lasting biocidal activity.     

Suppression of radiation‐induced oxidation of polymers by sputtered silicon oxide coating

Oxygen barrier coating on polymers was attempted to obtain polymeric composite materials with improved radiation resistance. Silicon oxide (SiO_1.6) films ranging from 120 to 240 nm thick were formed on polypropylene (PP) and polyethylene (PE) by radio frequency (RF) magnetron sputtering. Oxygen permeability after SiO_1.6 deposition was reduced significantly in all samples studied, indicating that silicon oxide is a useful gas barrier. The oxygen permeability coefficient of deposited films for PP was 1.7–2.2 × 10^?14 cm³‐cm/cm²/s/cmHg and that for PE was 2.8–4.8 × 10^?13 cm³‐cm/cm²/s/cmHg. We studied the effect of such films on the radiation resistance of polymers in the presence of oxygen by microscopic infrared (IR) absorption spectroscopy. Silicon oxide films 180 nm thick were deposited on the surfaces of PP and PE, and the formation of carbonyl groups after irradiation in air was measured as a function of depth from the surface. Results compared with those for uncoated PE and PP showed that the radiation‐induced polymer oxidation is dramatically suppressed by silicon oxide coating. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 186–190, 2002     

一种新颖的含黄酮结构可交联高分子染料的合成与染色性能研究(英文)

A yellow crosslinking polymeric dye was prepared by grafting the flavone moiety containing azo chromophore onto polyvinylamine backbone.The λ max of this polymeric dye in water is 382 nm.The polymeric dye is fixed to silk and cotton with a crosslinking agent,2-chloro-4,6-di(aminobenzene-4’-β-sulphatoethylsulphone)-1,3,5-s-triazine,which acts as a bridge between the fiber and dye molecules.The fixation of this polymeric dye reaches 99% and the dyed samples exhibit excellent rubbing and washing fastness.     

Radiationresistance and thermal stability of nylon 6, acrylonitrile copolymer and polyester fabrics

The thermal stability and radiation resistance of three polymers Nylon 6, acrylonitrile copolymer and polyester were investigated. The polymer samples were irradiated by low rate fission neutrons from a ²⁵²Cf source. The polyester showed a higher heat and radiation resistance than the two other polymers. It has to be recommended herein that polyester is the most suitable fiber for the manufacture of products in which heat buildup is produced during application, or products where radiation and heat resistance are required.     

Photodynamic inactivation of bacterial spores on the surface of a photoactive polymer

Novel photoactive polymers were prepared by covalently binding an anthraquinone (AQ) derivative through its 2-position to acid groups of a commercially available ethylene–acrylic acid copolymer, and the photodynamic action of films prepared using these polymers was evaluated. Inoculation of Bacillus cereus spores onto the surface of photoactive polymer films having an AQ content of 35% w/w, followed by exposure to low-power UV-A light, was found to significantly enhance the inactivation of the spores compared with their survival on the surface of inert polymer substrates. It was shown that this effect most likely originates from the photo-induced production of singlet oxygen by the photoactive polymer. These results provide compelling evidence that singlet oxygen produced exogenously by a polymeric substrate can successfully inactivate microbes located on the substrate’s surface.     

Near-infrared emissive BODIPY polymeric and copolymeric dyes

Novel near-Infrared emissive BODIPY polymeric dyes (polymers A and B) were prepared by Sonogashira cross-coupling reaction of 2,6-diiodo BODIPY dyes bearing one and two styryl groups at 3,5 positions (5, 6) with 2,6-diethynyl BODIPY dye, respectively. These polymeric dyes (A and B) display absorption maxima at 697 and 738 nm, and emission maxima at 715 and 760 nm, respectively. These polymeric dyes exhibit significant red shifts in absorption and emission maxima due to their extended π-conjugation systems compared with their BODIPY monomeric dyes. The thin films of polymers A and B display further red shift with emission maxima 764 and 810 nm, respectively. Near-infrared BODIPY copolymeric dye (C) was prepared by Sonogashira polymerization of 2,6-diiodo BODIPY dye bearing two styryl groups with 2,5-diethynyl-3-decylthiophene. For comparison in optical properties, deep-red and red emissive BODIPY copolymeric dyes (D and E) were prepared by Sonogashira polymerization of 2,6-diiodo BODIPY dye bearing monostyryl group and 2,6-diiodo BODIPY dye with 2,5-diethynyl-3-decylthiothene, respectively. These polymers display their absorption maxima at 649 nm and 634 nm, and emission maxima at 694 nm and 669 nm, respectively. All the polymers displayed good thermal stability and solubility in dichloromethane, and their lifetimes ranged from 0.7 to 3.4 ns.     

Physico-Chemical Problems in Estimation of Service Steadiness (SS) of Polymer Materials

Abstract

The polymers ageing process investigation encounts too much problems of physical-chemistry polymer science.

The question is to understand the nature of stresses localization in radiation oxidized polyethylene with the characteristic time equal to several decades, the non-correlation between theoretical ideas as for sol's consistence changing and swelling coefficient in the ageing process of latex films, the photoageing of lightstable materials exposed by the light of different polychromic spectra.