P-phenylenediamine Research Articles

Internal exposure of hairdressers to permanent hair dyes: a biomonitoring study using urinary aromatic diamines as biomarkers of exposure

To determine whether the occupational exposure of hairdressers to permanent hair dyes can be quantified by the use of biological monitoring of urinary aromatic diamines as one of the main constituents and to compare these levels to those recently determined in persons after personal application of hair dyes. Fifty-two hairdressers (40 female and 12 male) from 16 hairdresser salons in and around the city of Aachen took part in this field study. Subjects were asked to document all operations associated with possible exposure to permanent hair dyes like mixing colour, application of colour, washing after dyeing, and cutting of freshly coloured hair. Excretion of aromatic diamines 2,5-toluylene diamine (2,5-TDA) and p-phenylene diamine (p-PDA) as main constituents of commercially available hair dyes was measured in urine samples using a highly specific and accurate GC/MS-method. Urine samples were taken at 5 points of time during the work week: pre-shift before the start of the work week, pre- and post-shift on the third day of the work week and finally pre- and post-shift on the last day of a work week in order to meet different workloads and possible accumulative effects over the week. Nineteen persons matched for age served as a control group and gave spot urine samples. Although the levels were generally low, we could determine a significantly higher internal exposure to 2,5-TDA in hairdressers (medians ranged from <0.2 μg/g creatinine up to 1.7 μg/g creatinine at various sampling times, with a maximum of 155.8 μg/g creatinine) compared to the control group (median <0.2 μg/g creatinine, maximum 3.33 μg/g creatinine). At the same time, p-PDA was detectable only in selected cases in the group of hairdressers but not in the control group. Overall, there was neither an intra-shift effect seen nor an effect across the work week. There was also no significant difference in urinary excretion of participants who reported wearing protective gloves compared to those who reported not wearing protective gloves. The internal exposure to aromatic diamines in hairdressers using permanent hair dyes can be determined using biological monitoring. The extent of exposure is low compared to subjects after personal application of hair dyes, who excreted more than 200 times higher amounts of aromatic diamines. This slight work-related exposure might be reduced by the strict adherence to the use of suitable gloves as well as long-sleeved clothing.

Adsorption Properties of Thin Films Prepared by RF Sputtering with a Poly(biphenyltetracarboxylic dianhydride–paraphenylene diamine) Polyimide Target

Thin films were deposited onto a quartz crystal with a poly(biphenyltetracarboxylic dianhydride–paraphenylene diamine) (BPDA–PDA) polyimide target by RF sputtering, and the adsorption properties of these thin films for water, ethanol, acetone, acetaldehyde, toluene, and methyl salicylate were evaluated by the quartz crystal microbalance (QCM) method to characterize the surface properties of these thin films. Chemical structures, especially surface free energies of these thin films would affect the gas adsorption properties. In addition, the number of adsorbed gas molecules increased with decreasing molecular weight on each sputtered thin film. Furthermore, these gas molecules would be adsorbed inside the sputtered thin films as well as on the top surface. The number of adsorbed gas molecules increased with decreasing molecular size on each sputtered thin film.

Hair dye poisoning – an emerging problem in the tropics: an experience from a tertiary care hospital in South India

Super-Vasmol, a cheap, freely-available hair dye is emerging as a major cause of suicidal poisoning in India. It contains potential toxins including paraphenylene diamine, resorcinol, sodium ethylenediaminetetraacetic acid and propylene glycol which can result in multiorgan dysfunction. A retrospective study was conducted over 3.5 years (January 2006-July 2009) of 13 consecutive patients with Super-Vasmol poisoning admitted to a tertiary care, referral hospital in South India. A chart review including records of clinical presentations, laboratory findings and treatment details was carried out. Eleven of the patients were women and the mean age was 27.2 years. The predominant clinical features were cervico-facial oedema and pain, cola-coloured urine and oliguria. Laboratory investigations revealed elevated hepatic transaminases (100%), leucocytosis (92.3%), elevated creatinine phosphokinase (92.3%), metabolic acidosis (84.6%), hypocalcaemia (61.5%), hyperphosphataemia (46.2%) and renal failure (38.5%). Eight of the patients were discharged with complete recovery. Trends towards a poor outcome were evident among the following patients: late presentation at our centre; when no gastric lavage was done at the primary-care centre; those requiring tracheostomy/intubation at the primary centre; presentation with a low Glasgow Coma Score or seizures; established renal failure; and those who subsequently require dialysis, mechanical ventilation or intensive care. Hair dye poisoning classically presents with cervico-facial oedema, severe rhabdomyolysis and renal failure. Early therapy with tracheostomy and aggressive forced diuresis are essential in order to prevent the high mortality associated with this toxin. It is imperative to raise public awareness of the potential toxicity of the dye as well as to educate physicians about the need for aggressive and early treatment.

몇 개의 전이금속 이온과 고분자와 고분자 Complex의 합성과 특성연구

p-페닐렌 디아민과 maleic anhydride, 아세틸 아세톤과 커플된 O-아미노 페놀의 아조화합물으로 부터 폴리이미드가 만들어졌다. 합성된 폴리이미드(PA)는 DMF용매 속에 다른 몰비율로 녹아있는 <TEX>$Co^{+2},\;Cr^{+2},\;Ni^{+2},\;Cu^{+2},\;Zn^{+2},\;Cd^{+2}$</TEX> and <TEX>$Fe^{+3}$</TEX> 를 포함하는 전이금속이온들의 금속염들과 함께 환류되었다. 이 complex들은 원소분석과 열분석, IR, <TEX>$^1H$</TEX> NMR으로 구조분석, 특성 연구되었다. Polyamide derived from azo compound of o-amino phenol coupled with acetyl acetone, maleic anhydride acid and p-phenylene diamine were prepared. The prepared polyamide (PA) was refluxed with metal salts of transition metal ions include, <TEX>$Co^{+2},\;Cr^{+2},\;Ni^{+2},\;Cu^{+2},\;Zn^{+2},\;Cd^{+2}$</TEX> and <TEX>$Fe^{+3}$</TEX> in dimethyl formamide (DMF) in different molar ratios. These complexes were characterized and identified by elemental and thermal analysis, IR, 1H NMR spectra. The data showed that PA ligand coordinates with metal ions in abidentate manner through donating N=N and O-H groups. The metal ions are surrounded by coordinated water molecules and anions to establish the geometrical structure of the complexes. The thermal analysis degradation at different temperatures explained the weight loss of hydrated water and the decompositions of complexes until a constant weight loss of metal oxides is obtained.

Levels of plasma ceruloplasmin protein are markedly lower following dietary copper deficiency in rodents

Ceruloplasmin (Cp) is a multicopper oxidase and the most abundant copper binding protein in vertebrate plasma. Loss of function mutations in humans or experimental deletion in mice result in iron overload consistent with a putative ferroxidase function. Prior work suggested plasma may contain multiple ferroxidases. Studies were conducted in Holtzman rats ( Rattus norvegicus), albino mice ( Mus musculus), Cp−/− mice, and adult humans ( Homo sapiens) to investigate the copper–iron interaction. Dietary copper-deficient (CuD) rats and mice were produced using a modified AIN-76A diet. Results confirmed that o-dianisidine is a better substrate than paraphenylene diamine (PPD) for assessing diamine oxidase activity of Cp. Plasma from CuD rat dams and pups, and CuD and Cp−/− mice contained no detectable Cp diamine oxidase activity. Importantly, no ferroxidase activity was detectable for CuD rats, mice, or Cp−/− mice compared to robust activity for copper-adequate (CuA) rodent controls using western membrane assay. Immunoblot protocols detected major reductions (60–90%) in Cp protein in plasma of CuD rodents but no alteration in liver mRNA levels by qRT-PCR. Data are consistent with apo-Cp being less stable than holo-Cp. Further research is needed to explain normal plasma iron in CuD mice. Reduction in Cp is a sensitive biomarker for copper deficiency.

Kevlar Functionalized Carbon Nanotubes for Next-Generation Composites

We report a sequential functionalization methodology for the covalent modification of multiwalled carbon nanotubes (MWNTs) with one and a half repeat units of the polymer poly-p-phenyleneterephthalamide (PPTA), Kevlar. Covalent attachment of PPTA monomer units, p-phenylenediamine (PDA) and terephthaloyl chloride (TPC), to the surface of MWNTs results in PPTA oligomer units forming an organic sheath around the nanotubes, PPTA-functionalized-MWNTs (PPTA-MWNTs). PPTA-MWNTs possess chemical functionality identical to that of PPTA, and thus provide nanoscale scaffolds which may be readily dispersed within a monomer solution and participate in the polymerization reaction to form a PPTA-MWNT/PPTA composite. We show that formation of PPTA in the presence of PPTA-MWNTs leads to a uniform dispersion of MWNTs within the polymer matrix, in contrast to aggregated masses of MWNTs in the case of pristine-MWNTs. The covalent attachment of oligomeric PPTA units to the surface of MWNTs represents the formation of a functio...

Preparation and characterization of polysulfonamide statistical copolymers from three aromatic diamines

Various polysulfonamide (PSA) statistical copolymers were synthesized by polycondensation of three aromatic diamines and terephthaloyl chloride. The inherent viscosities of the resulting PSA copolymers range from 1.54 to 1.66 dL/g. The precipitated PSA copolymers with feed content of p-phenylene diamine (PPD) being less than 50% (mole fraction) can be redissolved in N-methyl-2-pryrrolidone (NMP) or N,N-dimethylacetamide (DMAc) with lithium chloride of wLiCl = 0.02. All of the PSA copolymers exhibit enhanced tensile strength in comparison with PSA and still maintain excellent thermal stability in either air or nitrogen atmosphere

Spontaneous molecular orientation of polyimides induced by thermal imidization (6). Mechanism of negative in-plane CTE generation in non-stretched polyimide films

The mechanism of negative coefficient of thermal expansion (CTE) generation for non-stretched polyimide (PI) films is proposed in this work. Negative CTE behavior was observed in some miscible binary blend films composed of a major fraction of a rod-like semi-crystalline PI derived from pyromellitic dianhydride (PMDA) with p-phenylenediamine (PDA) and flexible PIs based on 2,3,3′,4′-biphenyltetracarboxylic dianhydride (a-BPDA) whereas homo PMDA/PDA PI film shows a considerably low but a positive CTE value. The results suggest that the negative CTE generation is related to not only a considerably high extent of in-plane orientation of the PMDA/PDA chains but also to the crystallinity of the blends. The present work revealed that some other PIs, a poly(ester imide), and a polybenzoxazole system also display negative CTE and these systems also possess extremely high extents of in-plane chain orientation without exception. In addition to CTE, the morphologies were monitored as a function of imidization temperature for two PI systems, PMDA/2,2′-bis(trifluoromethyl)benzidine and PMDA/m-tolidine by wide-angle X-ray diffraction, FT-IR spectroscopy, birefringence, and film density measurements. The results suggested that the negative CTE phenomenon occurs when PI films possess very high extents of in-plane orientation and a less crystalline morphology simultaneously, thereby significant thermal expansion can be allowed to the thickness direction.

Electrophoretic deposition of graphene nanosheets on nickel foams for electrochemical capacitors

Graphene nanosheets are deposited on nickel foams with 3D porous structure by an electrophoretic deposition method using the colloids of graphene monolayers in ethanol as electrolytes. The high specific capacitance of 164 F g −1 is obtained from cyclic voltammetry measurement at a scan rate of 10 mV s −1. When the current densities are set as 3 and 6 A g −1, the specific capacitance values still reach 139 and 100 F g −1, respectively. The high capacitance is attributed to nitrogen atoms in oxidation product of p-phenylene diamine (OPPD) adsorbed on the surface of the graphene nanosheets. The comparable results suggest potential application to electrochemical capacitors based on the graphene nanosheets.

Electrochemical synthesis of belt-like polyaniline network on p-phenylenediamine functionalized glassy carbon electrode and its use for the direct electrochemistry of horse heart cytochrome c

Abstract Three-dimension (3D) belt-like polyaniline (PAN) network has been prepared via electrochemical polymerization of aniline on p-phenylenediamine (PDA) functionalized glassy carbon electrode (GCE) using a three-step electrochemical deposition procedure. PDA was covalently binded on GCE via the formation of carbon–nitrogen bond between amine cation radical and the aromatic moiety of GCE surface using electrochemical oxidation procedure. X-ray photo-electron spectroscopy (XPS) and cyclic voltammetry have been performed to characterize the attachment of PDA on GCE. The images of scanning electron microscope (SEM) show that the 3D belt-like PAN network is uniform. The width and thickness of the PAN belt varies in the range of 1.5–5.5 μm and 0.1–0.8 μm, respectively. The distance between the belt-contacts ranges from 2.5 to 15 μm. The 3D belt-like PAN network modified GCE (PAN–PDA/GCE) exhibits an improved electro-activity of PAN at an extended pH up to 7.0. The PAN–PDA/GCE not only immobilizes but also leads to a direct electrochemical behavior of cytochrome c (Cyt c). The immobilized Cyt c maintains its activity, showing a surface-controlled electrode process with the electron-transfer rate constant (ks) of 14.8 s−1 and electron-transfer coefficient (α) of 0.48, and could be used for the electrocatalytic reduction of hydrogen peroxide (H2O2).

Spontaneous molecular orientation of polyimides induced by thermal imidization (4): Casting- and melt-induced in-plane orientation

Driving forces of in-plane chain orientation of polyimides (PIs) and their precursors were discussed and the mechanisms were proposed. A polyimide precursor, poly(amic acid) (PAA) derived from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA) with p-phenylenediamine (PDA) showed a certain degree of in-plane orientation in its solution-casting process and clear molecular weight dependence. The results allowed us to propose the casting-induced in-plane orientation mechanism of the rigid PAA chains. The imidization-induced in-plane orientation mechanism was also discussed by investigating how residual solvent content influences the degree of in-plane orientation of resultant PI films. The results suggested that the magnitudes of the PI chain in-plane orientation are dominated by a combined effect of the initial PAA orientation, apparent stretching based on a great thickness decrease, and the molecular mobility during thermal imidization. In a system derived from s-BPDA with 2,2′-bis(trifluoromethyl)benzidine (TFMB), the effect of molecular mobility during thermal imidization was predominant when cured under usual thermal conditions owing to the presence of the trifluoromethyl groups contributing to weakened intermolecular interaction. In s-BPDA/TFMB and s-BPDA/m-TOL systems (m-TOL = m-tolidine), a melt-induced in-plane orientation phenomenon was observed at temperatures corresponding to their T g’s when the extents of in-plane chain orientation ( f values) were monitored as a function of temperature in the stepwise heating process. This behavior is very curious because there are no appreciable dimensional, morphological, and structural changes as some driving forces just above the T g of s-BPDA/TFMB.

Acute renal failure owing to paraphenylene diamine hair dye poisoning in Sudanese children

Paraphenylene diamine (PPD) has traditionally been used as a dark-coloured hair dye. In Sudan, it is used by women to colour their hair and as a body dye when added to henna (Lawasonia alba). Accidental or deliberate ingestion causes severe systemic toxicity. Although a wide variety of complications has been described, there are few reports in children. To describe the clinical features, management and outcome of PPD intoxication in Sudanese children. Data for a 3-year period (2006-2008) were extracted from the medical records of the Paediatric Nephrology Unit, Soba University Hospital. Information included the circumstances of poisoning, gender, age distribution, clinical presentation, biochemical findings and outcome. Over the 3-year period, 17 children (16 female) were admitted to the Paediatric Nephrology Unit with PPD intoxication. Mean age was 13.8 yrs (range 2-18). Thirteen (76.4%) had attempted suicide, three (17.6%) were poisoned as a result of attempted murder and one poisoning (5.8%) was accidental. Eight children (47%) required tracheostomy for severe angioneurotic oedema. Of 12 (71%) who developed acute renal failure (ARF), nine required dialysis and three were managed conservatively. Two children (12%) died and the other 15 recovered with normal renal function. PPD intoxication is a life-threatening condition with significant morbidity and mortality in children. Clinical manifestations and outcome are similar to those in adults. Mortality can be reduced by early recognition, prompt referral and aggressive supportive treatment.

Polycationic States of Oligoanilines Based on Wurster's Blue

AbstractPolycations of two oligoanilines based on Wurster's blue,N,N′,N″‐tris[4‐(dimethylamino)phenyl]‐N,N′,N″‐trimethyl‐1,3,5‐benzenetriamine (2) and N,N′‐bis(3‐{N‐[4‐(dimethylamino)phenyl]‐N‐methylamino}phenyl)‐N,N′‐dimethyl‐p‐phenylenediamine (3), have been generated efficiently by a stepwise oxidation procedure. Their redox behavior was characterized in terms of the embedded p‐phenylenediamine (PD) units and their intramolecular connectivity. EPR analysis of the oxidized 2 and 3 species revealed the existence of high‐spin species in solution. It was found that spin multiplicities of the dominant polycationic species of 2 and 3 formed by 3 equiv. of oxidant can be assigned to quartet and doublet states, respectively on the basis of pulsed EPR spectroscopy. These results demonstrate that the intramolecular connectivity between the spin‐containing units decisively influences the spin preference of the multispin systems based on oligoanilines.(© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2009)

Chemical Mechanisms for Skin Sensitization by Aromatic Compounds with Hydroxy and Amino Groups

It is well-known that aromatic diamino-, dihydroxy-, and amino-hydroxy compounds, with NH(2) and OH groups in ortho- or para-positions relative to each other, are strong skin sensitizers. In this paper, we analyze published potency and cross-reactivity data, whereby animals sensitized to one of these compounds are challenged with other compounds. The data are consistent with two parallel chemical reaction mechanisms: oxidation to electrophilic (protein reactive) quinones or quinone imines or formation of protein-reactive free radicals such as the Wurster salt, which can be formed by para-phenylene diamine. Compounds with NH(2) and OH groups meta to each other have also been found to be skin sensitizers, in some cases quite strong sensitizers. For these compounds, direct formation of quinones or quinone imines is not possible, and free radicals of the Wurster salt type are not favored. Here, we present a molecular mechanism to rationalize the sensitization potential of such compounds and, using the results of quantum mechanics calculations, show how this mechanism can explain observed structure-potency trends.

Hepatic Histopathological Abnormalities in Rats Treated Topically with Para-Phenylene Diamine (PPD)

Hepatic Histopathological Abnormalities in Rats Treated Topically with Para-Phenylene Diamine (PPD)

Kinetics of reductive alkylations of phenylenediamines: Influence of substrates isomeric structure

Reductive alkylation of ortho-, meta- and para-phenylenediamines (PDAs) with methyl ethyl ketone (MEK) has been studied in a semi-batch slurry reactor in the presence of a commercial 3% Pt/Al 2O 3 catalyst. It was observed that the PDA isomers differ remarkably from each other in their activity in reductive alkylation and product distribution. The activity was found to decrease in the following order: PPDA>OPDA>MPDA. To understand the substrate structure–activity correlation, the homogeneous equilibrium reactions involved in the alkylation step and the overall catalytic reactions were studied separately. Kinetics of reductive alkylation of PDAs with MEK as a solvent and alkylating agent with 3% Pt/Al 2O 3 catalyst was studied in a semi-batch slurry reactor over a temperature range of 373–453 K and pressure range of 2.07–6.21 MPa. Semi-batch slurry reactor models were developed and kinetic parameters were estimated by fitting the integral batch reactor data at different temperatures to understand the influence of different reaction steps on the activity and selectivity of different products.

Direct Synthesis of Wholly Aromatic Polyamides by Using Reaction-Induced Crystallization

Direct synthesis of rigid-rod aromatic polyamides was studied without condensation reagents by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of p-aminobenzoic acid were carried out in an aromatic solvent at a polymerization concentration of 20% at 350 °C. High molecular weight poly(p-benzamide) (PBA) was obtained in the form of plate-like crystals, and the highest molecular weight was 11.6 × 103. In this polymerization, the oligomers were formed in the solution by the condensation reaction with the elimination of water. When the molecular weight of oligomers exceeded the critical value, the oligomers were precipitated by crystallization via supersaturated state to form the plate-like crystals. The molecular weight increased by the polymerization between the oligomers on and in the crystals. Poly(p-phenylene isophthalamide) (PPIA) was also obtained in the form of plate-like crystals by the polymerization of p-phenylene diamine (PPDA) and isophthalic acid (IPA) under the same condition as that of PBA. These results exhibited the thermally direct synthesis of infusible aromatic polyamides. Sequential addition of monomers into this heterogeneous polymerization was examined to increase the molecular weight. In the step-growth polymerization, the addition of monomers into the homogeneous polymerization could not increase the molecular weight because it was determined by the extent of reaction and reshuffled by the transamidation reaction. However, the addition of PPDA and IPA during the polymerization resulted in the increase in the molecular weight of PPIA. This result gave possibly a novel procedure for the preparation of high molecular weight condensation-type polymers.

A variety of oxidation products of antioxidants based on N, N′-substituted p-phenylenediamines

Electrochemical and spectroscopic (EPR, UV–Vis, IR) studies of the aromatic secondary amines N, N′-diphenyl-1,4-phenylenediamine (DPPD), N-phenyl- N′-isopropyl- p-phenylene diamine (IPPD), N-phenyl- N′-(α-methylbenzyl)- p-phenylenediamine (SPPD) and N-phenyl- N′-(1,3-dimethyl-butyl)- p-phenylenediamine (6PPD), which represent the most important group of antioxidants used in the rubber industry, are presented. During oxidation, all the compounds show reversible redox couples in acetonitrile/0.1 M TBABF 4. The first oxidation potential depends substantially on the R substituent at the –N′H– moiety. Very similar UV–VIS spectra of monocation radicals and dications for all the compounds were observed by applying anodic oxidation as well as oxidation by tert-butyl hydroperoxide both in air and in inert atmosphere. The samples with N′-bonded aliphatic carbon in the molecule (e.g. IPPD) heated in air undergo consecutive chemical reactions leading to the formation of –N′ C– group. By the use of RO 2 radicals only very low concentration of nitroxide radicals was obtained. Very high concentration of nitroxide radicals was achieved using 3-chloroperbenzoic acid. In the oxidation of investigated aromatic secondary amines with powder PbO 2 no EPR spectra were observed and UV–Vis and IR studies indicate the rapid formation of the final dehydrogenated oxidation product.

Advances in mechanism of hair dye dermatitis

Pare-phenylenediamine is the main functional component of hair dyes,and also a most potent contact allergen in hair dye dermatitis.Studies have shown that the activation of human dendritic ceils,production of some cytokines,and γδT cells are involved in P-phenylenediamine allergy.The genetic polymorphism of N-acetyltransferase,angiotensin-converting enzyme and manganese superoxide dismutase is reported to be associated with the development of hair dye dermatitis.This article gives an update on hair dye dermatitis-related immune factors and genetic susceptibilities. Key words: Dermatitis,contact; Hair dyes; Immunity

Copper proteins and ferroxidases in human plasma and that of wild-type and ceruloplasmin knockout mice

In the blood plasma of humans and rats, ceruloplasmin is the major copper-binding protein and ferroxidase, accounting for 70% of the copper present in the plasma, with the rest binding primarily to albumin and a macroglobulin. Systematic studies with fresh plasma were carried out to compare what occurs in the mouse. C57BL6 mice had half as much copper and pPD (p-phenylene diamine) oxidase activity as humans and rats, 20-40% as much ferroxidase activity as humans (determined using three different assays) and less inhibition by azide. Plasma from ceruloplasmin knockout mice had no pPD oxidase activity, but retained >50% ferroxidase activity (which was not as affected by azide). Modelling of mouse ceruloplasmin against the known X-ray structure of human ceruloplasmin indicated subtle but potentially significant changes in the pPD- and azide-binding sites. Purification and in-gel assays after native PAGE confirmed that mouse ceruloplasmin had ferroxidase activity but revealed an additional ferroxidase in ceruloplasmin knockout mouse plasma, which is also seen in size-exclusion chromatography. In the wild-type mouse, the 'ceruloplasmin' peak contained approximately 55% of the total copper, but ceruloplasmin knockout plasma exposed a major additional peak (180 kDa) which co-eluted with ferroxidase activity. Two other ferroxidases (700 and 2000 Da) were also detected in mouse and human plasma. Mammalian blood thus contains copper components and ferroxidases not reported previously.