硝基苯透皮吸收规律及其防护研究

研究了硝基苯对完整小鼠腹皮的透过性和两种实验室常用手套对硝基苯的防护作用。采用Franz扩散池进行体外透皮试验和手套透过试验,以完整小鼠腹皮、手套为渗透屏障,HPLC法测定硝基苯的透过量。高、低浓度硝基苯透皮均为零级动力学过程,其24h累计透过率分别达48.94%和43.97%;两种手套都未能阻止硝基苯的透过,其24h累计透过率可达10%左右。高、低浓度硝基苯对皮肤的渗透能力都很强,且能穿透实验室常用的一次性手套和乳胶手套。     

Mechanism on the permeation of ethanol in nitrile gloves studied using positron annihilation lifetime spectroscopy

Positron annihilation lifetime spectroscopy (PALS) was applied to study the mechanism of ethanol diffusion through commercial nitrile rubber gloves. Even though the untreated raw samples were very different in their colors and area densities (g/cm²), the correlation between the ethanol diffusion coefficient from permeation test and the free volume from PALS measurement is well consistent with the Vrentas‐Duda model. Via combining the PALS technique and the Vrentas‐Duda theory, it is revealed that (a) the diffusion coefficient is correlated to the number of free volume holes rather than the average size of holes, (b) the diffusion process is not regulated by the size of ethanol molecule but by the size of critical volume for polymer segments to migrate, (c) nitrile group does not present in the free volume hole where the diffusion of ethanol molecule takes place, but is embedded in polymer matrix, and therefore, does not directly interact with ethanol molecule, and (d) nitrile group affects the average size, but not the number of free volume holes. The experiment demonstrates that the PALS technique, being mainly used in pure academic researches, might have application in the glove industry due to its ability in measuring terminal free volume quantities, which are directly related to the permeation of small organic molecules through protective gloves. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41282.     

Acrylonitrile content as a predictor of the captan permeation resistance for disposablenitrile rubber gloves

The aim of this study was to determine whether the acrylonitrile (ACN) content influences the permeation resistance of disposable nitrile rubber (NBR) gloves to aqueous solutions of the pesticide captan. Attenuated total reflectance/Fourier transform infrared (ATR–FTIR) spectrophotometry at 2237 ± 5 cm^?1 was used to measure the ACN contents of seven different NBR gloves. The ACN contents of the gloves ranged from 12.7 to 29.9%. Permeation was conducted according to American Society for Testing and Materials (ASTM) Method F 739‐99a with a gas chromatography/mass spectrometry analysis of captan in the hexane collection liquid. Significant correlations were found between (1) the ACN content and mass‐to‐area ratio and the logarithm of the steady‐state permeation rate (SSPR; Pearson correlation coefficient = 0.9227, p ≤ 0.05), and (2) the ACN content and mass‐to‐area ratio and the ASTM normalized breakthrough detection time (NBT) at 0.25 μg/cm² (Pearson correlation coefficient = 0.9471, p ≤ 0.05). On average, the NBT increased 120 min for every 5% increase in the ACN content. The average SSPR ranged from 0.002 to 0.40 μg/cm²/min, a 200‐fold difference. Increasing the ACN content resulted in decreased SSPR. ATR–FTIR was useful in determining the NBR polymer ACN content, surface homogeneity, and potential glove chemical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2057–2063, 2007     

Over‐expression of glycerol dehydrogenase and 1,3‐propanediol oxidoreductase in Klebsiella pneumoniae and their effects on conversion of glycerol into 1,3‐propanediol in resting cell system

BACKGROUND: Glycerol dehydrogenase [EC.1.1.1.6] and 1,3‐propanediol oxidoreductase [EC.1.1.1.202] were proved to be two of the key enzymes for glycerol conversion to 1,3‐propanediol in Klebsiella pneumoniae under anaerobic conditions. For insight into their significance on 1,3‐propanediol production under micro‐aerobic conditions, these two enzymes were over‐expressed in K. pneumoniae individually, and their effects on conversion of glycerol into 1,3‐propanediol in a resting cell system under micro‐aerobic conditions were investigated. RESULTS: In the resting cell system, over‐expression of 1,3‐propanediol oxidoreductase led to faster glycerol conversion and 1,3‐propanediol production. After a 12 h conversion process, it improved the yield of 1,3‐propanediol by 20.4% (222.1 mmol L⁻¹ versus 184.4 mmol L⁻¹) and enhanced the conversion ratio of glycerol into 1,3‐propanediol from 50.8% to 59.8% (mol mol⁻¹). Over‐expression of glycerol dehydrogenase in K. pneumoniae had no significant influence both on 1,3‐propanediol yield and on the conversion ratio of glycerol into 1,3‐propanediol in the resting cell system. CONCLUSION: The results were important for an understanding of the significance of glycerol dehydrogenase and 1,3‐propanediol oxidoreductase in 1,3‐proanediol production under micro‐aerobic conditions, and for developing better strategies to improve 1,3‐propanediol yield. Copyright © 2008 Society of Chemical Industry     

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

At present, the most common used crosslinking process for carboxylated nitrile butadiene rubber (XNBR) latex is an accelerated sulfur curing system with zinc oxide. To avoid allergenic reactions related to residual accelerator levels in dipped XNBR latex articles such as medical gloves, a dual curing process has been developed combining thermal and photochemical crosslinking reactions. The two‐step procedure involves the formation of covalent and ionic bonds to ensure good mechanical properties of the final products. The photochemical thiol‐ene reaction is used to generate covalent crosslinks between the remaining C?C double bonds of the butadiene units whereas the carboxylic moieties are conventionally cured with divalent metal oxides (ZnO) under elevated temperature (formation of ionic crosslinks). The photochemical curing step is carried out both in the latex phase using a falling film photoreactor (prevulcanization) as well as in the solid phase by UV irradiation of dried XNBR films (postvulcanization). The mechanical properties and crosslink densities of the cured XNBR films are determined and the influence of selected curing parameters is assessed. The results give evidence that a combined approach of thermal prevulcanization and photochemical postvulcanization makes the production of latex articles (e.g., gloves) with tailored properties and good skin compatibility feasible. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Simultaneous refolding,purification, and immobilization of recombinant Fibrobacter succinogenes 1,3‐1,4‐β‐D‐glucanase on artificial oil bodies

BACKGROUND: 1,3‐1,4‐β‐D‐glucanase (1,3‐1,4‐β‐D‐glucan 4‐glucanohydrolase; EC 3.2.1.73) has been used in a range of industrial processes. As a biocatalyst, it is better to use immobilized enzymes than free enzymes, therefore, the immobilization of 1,3‐1,4‐β‐D‐glucanase was investigated. RESULTS: A 1,3‐1,4‐β‐D‐glucanase gene from Fibrobacter succinogenes was overexpressed in Escherichia coli as a recombinant protein fused to the N terminus of oleosin, a unique structural protein of seed oil bodies. With the reconstitution of the artificial oil bodies (AOBs), refolding, purification, and immobilization of active 1,3‐1,4‐β‐D‐glucanase was accomplished simultaneously. Response surface modeling (RSM), with central composite design (CCD), and regression analysis were successfully applied to determine the optimal temperature and pH conditions of the AOB‐immobilized 1,3‐1,4‐β‐D‐glucanase. The optimal conditions for the highest immobilized 1,3‐1,4‐β‐D‐glucanase activity (7.1 IU mg^?1 of total protein) were observed at 39 °C and pH 8.8. Furthermore, AOB‐immobilized 1,3‐1,4‐β‐D‐glucanase retained more than 70% of its initial activity after 120 min at 39 °C, and it was easily and simply recovered from the surface of the solution by brief centrifugation; it could be reused eight times while retaining more than 80% of its activity. CONCLUSIONS: These results indicate that the AOB‐based system is a comparatively simple and effective method for simultaneous refolding, purification, and immobilization of 1,3‐1,4‐β‐D‐glucanase. Copyright © 2009 Society of Chemical Industry     

Lipid Oxidation and Degradation Products in Raw Materials: Low‐Fat Topical Skin‐Care Formulations

Topical skin formulations with a lipid content below 15% were stored for 6 months at 5, 20, or 40 °C or for 2 weeks at 50 °C in darkness or at 20 °C with exposure to light for 6 months. The volatile lipid‐oxidation compounds formed during this storage period were compared to those formed in the raw materials during 3 months of accelerated stability storage at 40 °C. The volatile compounds were collected by dynamic headspace and analyzed using gas chromatography–mass spectrometry. It was possible to link eight out of nine volatile compounds detected during storage of topical skin formulations to the raw materials. In addition, a possible link between the appearance of butane nitrile and the decomposition of an initiator used for polyacrylate crosspolymer‐6 production was observed. The polymer may originate from texture modifiers added to the topical skin formulation or from plastics used for packaging of topical skin formulations. Furthermore, six well‐known lipid‐oxidation and nonenzymatic browning products were suggested to originate from the two raw materials, tricaprylin/tricaprin and coconut oil.     

Tensile strength of handsheets from recovered fibers treated with N‐Methylol melamine and 1,3‐dimethylol‐4,5‐dihydroxyethyleneurea

The main objective of this study was to assess the effect of two amino resins, N‐methylol melamine (NMM) and 1,3‐dimethylol‐4,5‐dihydroxyethyleneurea (DMDHEU), on the intrafiber and interfiber strengths and water absorption of two types of waste paper categories, office paper (OP), and old corrugated containers (OCCs). The tensile strength of individual fibers measured at zero span was reduced by increases in the resin concentrations. The dry tensile strengths of the recovered handsheets measured at a finite span were enhanced with increases in the weight percentage gain of the resins. The increasing of the resin concentration also significantly improved the intrabonding of the OP and OCCs in moist measuring conditions. The water absorption of the handsheets considerably decreased at the higher concentration of the thermosetting resins, especially with NMM. The results are promising for the use of NMM‐ and DMDHEU‐treated recovered fibers as an alternative fiber resource for the production of laminated paper and also for the use of DMDHEU as a new N‐methylol compound for laminated paper. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41290.     

Highly Practical “Ligand‐Free‐Like” Copper‐Catalyzed N‐Arylation of Azoles in Lower Nitrile Solvents

In lower nitrile solvents, the N‐arylation of azoles with aryl halides was achieved efficiently in the presence of copper powder without any additional ligands. Thus, the first nitrile type of monodentate ligand‐mediated, “ligand‐free‐like” copper‐catalyzed N‐arylation procedure was established.     

Combined puncture and cutting of elastomer membranes: A fracture energy approach

Resistance to puncture or cutting by pointed blades is an important property of elastomer membranes and glove materials, making it necessary to define a fundamental criterion for measuring this resistance. However, the intrinsic properties controlling puncture/cutting crack propagation are still unidentified. This study has established a simple criterion describing the relationship between true fracture energy and the puncture/cutting process. Several samples of neoprene and nitrile rubber materials 1.6 mm and 3.2‐mm thick were tested using three pointed blades having tip angles of 22.5°, 35°, and 56°. It was found that both friction energy and true fracture energy contributed to global applied energy. True fracture energy, which is useful for in‐depth study of the puncture/cutting process, was independent of material thickness, blade geometry, and blade lubrication. Furthermore, friction energy was approximately twice as great as true fracture energy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44945.     

CO2/N2 separation ability and structural characteristics of poly(butadiene‐co‐acrylonitrile)‐based polyurethanes and hydrogenated nitrile rubbers

Two families of rubbery polymers, commercial hydrogenated nitrile rubbers and synthesized poly(acrylonitrile‐co‐butadiene)‐based polyurethanes with different amount of nitrile groups were studied as CO₂ selective membrane materials. The polymers were characterized by the techniques of FTIR, gel permeation chromatography, WAXD, and differential scanning calorimetry. The permeabilities of pure CO₂ and N₂ were measured using constant pressure/variable volume method at a feed pressure of 6 atm. With a higher amount of polar nitrile group within a given family of polymers, the permeability coefficient (P) was found to decrease, while the permselectivity (α) of these membranes was found to increase. The trade‐off between both transport parameters was less severe for the polyurethanes, which also showed much higher permeabilites. The results obtained were also discussed with respect to the polymer structure, and some relationships were found between P and T_g values. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Umpolung Synthesis of Diarylmethylamines via Palladium‐ Catalyzed Arylation of N‐Benzyl Aldimines

An umpolung synthesis of diarylmethylamine derivatives is presented. This reaction entails a palladium‐catalyzed arylation of 1,3‐diaryl‐2‐azaallyl anions, in situ generated from N‐benzyl aldimines. A Pd(NIXANTPHOS)‐based catalyst together with hindered silylamide bases enabled the coupling of aldimines with aryl bromides in good to excellent yields without product isomerization. Moreover, regioselectivity in the arylation of unsymmetrical 1,3‐diaryl‐2‐azaallyl anions was studied. This method is suitable for a gram scale synthesis of diarylmethylamine derivatives at room temperature without use of a glove box.

     

Fourier transform infrared and wide‐angle X‐ray diffraction studies of the thermal cyclization reactions of high‐molar‐mass poly(acrylonitrile‐co‐itaconic acid)

The stabilization reactions of a high‐molar‐mass poly(acrylonitrile‐co‐itaconic acid) precursor in air at 200, 220, and 240°C were studied with Fourier transform infrared. Principally, the cyclization of nitrile groups leading to the ladder structures of tetrahydropyridine occurred. Evidence for oxidative reactions causing the conversion of the C? C structure to C?C and generating groups such as ? OH and C?O was also obtained. As the temperature of stabilization was increased, the rate of the reaction increased without causing great changes in the Fourier transform infrared spectral patterns. The maximum nitrile conversion achievable was limited by the temperature of stabilization. Although the reaction stagnated at 40 and 80% at 200 and 220°C, it was practically complete in about an hour at 240°C. Higher temperatures also favored the formation of extended conjugated structures. Wide‐angle X‐ray diffraction studies of the polymer stabilized at 300 and 400°C in argon confirmed that the aromatization index value and the crystallinity of the polymer increased proportionally to the temperature of pyrolysis. An analysis of the wide‐angle X‐ray diffraction pattern and the elemental composition of the stabilized polymer implied the formation of the tetrahydropyridine structure at 400°C. The higher pyrolysis temperature favored the formation of the lattice constituted by this group. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3055–3062, 2006     

天然胶乳手套与合成胶乳手套的发展

介绍天然胶乳手套的起源和发展以及天然胶乳检查手套、外科手套、织物浸渍防护手套、家用手套、工业手套的用途、规格、特点和表面形式,指出因天然胶乳手套存在安全性能和使用性能的不足,促进了合成胶乳手套和人造胶乳手套的发展。丁腈胶乳检查手套因技术进步和成本降低成为天然胶乳检查手套的主要竞争者;低蛋白无粉天然胶乳外科手套、氯丁胶乳外科手套和聚异戊二烯胶乳外科手套成为对天然胶乳过敏症医护人员的选择;在非医疗领域,合成胶乳手套和人造胶乳手套适用于特殊领域的防护需求。     

Mechanical and thermal properties of thermoplastic random copolyesters made from lipid‐derived Medium and long chain poly(ω‐hydroxyfatty acid)s

The physical properties of novel thermoplastic random copolyesters [‐(CH₂)_n‐COO‐/‐(CH₂)_n‐COO‐]_x made of long (n = 12) and medium (n = 8) chain length ω‐hydroxyfatty esters [HO‐(CH₂)_n‐COOCH₃] derived from bio‐based vegetable oil feedstock are described. Poly(ω‐hydroxy tridecanoate/ω‐hydroxy nonanoate) P(?Me13?/?Me9?) random copolyesters (M_n = 11,000–18,500 g/mol) with varying molar ratios were examined by TGA, DSC, DMA and tensile analysis, and WAXD. For the whole range of P(?Me13?/?Me9?) compositions, the WAXD data indicated an orthorhombic polyethylene‐like crystal packing. Their melting characteristics, determined by DSC, varied with composition suggesting an isomorphic cocrystallization behavior. TGA of the P(?Me13?/?Me9?)s indicated improved thermal stability determined by their molar compositions. The glass transition temperature, investigated by DMA, was also found to vary with composition. The crystallinities of P(?Me13?/?Me9?)s however, were unaffected by the composition. The stiffness (Young's modulus) of these materials was found to be related to their degrees of crystallinity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40492.     

Preparation and properties of a novel bio‐based and non‐crystalline engineering elastomer with high low‐temperature and oil resistance

A series of poly(succinic acid/sebacic acid/itaconic acid/butanediol/propanediol) bio‐based and non‐crystalline engineering elastomers (BEE) were obtained by changing the molar ratio of succinic acid (SA) to sebacic acid (SeA) from 5:5 (BEE‐5) to 8:2 (BEE‐8). We prepared bio‐based engineering elastomer composites (BEE/CB) by mixing BEE with carbon black N330. The low‐temperature and oil resistance properties of the BEE/CB composites were investigated in terms of low‐temperature brittleness, coefficient of cold resistance under compression, oil resistance test at different temperatures, and tensile properties. The results showed that the low‐temperature brittleness temperature of the BEE/CB composites ranged from ?50 to ?60°C and the coefficient of cold resistance under compression was 0.18 high at ?60°C for BEE‐7/CB and 0.23 high at ?40°C for BEE‐8/CB. The oil resistance properties of BEE‐7/CB were higher than those of nitrile‐butadiene rubber N240S (NBR N240S), and the oil resistance properties of BEE‐8/CB were even as high as those of nitrile‐butadiene rubber N220S (NBR N220S). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42855.     

Polyelectrolytes with tetrazole pendant groups useful in the stabilization of Au and Ag nanoparticles

Stabilization of metallic nanoparticles is a challenge of enormous dimensions because the nanosize nanoparticles are not stable by themselves and therefore they tend to coalesce, forming large agglomerates causing the loss of the properties of individual nanoparticles. In this work, we report the synthesis of polyelectrolytes with tetrazole groups useful as stabilizing agents of Au and Ag nanoparticles. The polyelectrolytes with tetrazole groups were synthetized from the appropriate starting materials with nitrile groups, which were successfully converted to the corresponding 1H‐tetrazole rings using 1,3‐dipolar cycloaddition with ammonium azide. These new materials were characterized by NMR and FT‐IR techniques and they were used for the stabilization of Au and Ag colloidal nanoparticles at room temperature, using sodium borohydride as reducing agent. Formation and stabilization processes of the nanoparticles were monitored by UV‐vis spectroscopy. Shape and size of nanoparticles were studied by TEM. The polyelectrolytes with tetrazole pendant group are suitable materials for synthesis and stabilization of gold nanoparticles, obtaining average sizes lower than 10 nm. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43773.     

Synthesis and properties of some fluorescent 1,8‐naphthalimide derivatives and their copolymers with methyl methacrylate

Six new fluorescent derivatives of 1,8‐naphthalimide were synthesized. Three were dyes, and three were fluorescent whitening agents (FWAs) containing a tetramethylpiperidine (TMP) stabilizer fragment. The FWAs were obtained under phase‐transfer catalysis conditions. Five of the compounds were copolymerized with methyl methacrylate, so copolymers with an intense color and/or fluorescence stable against solvents were obtained. The chemical bonding of the synthesized monomers in the polymers was confirmed spectrophotometrically. The participation of the monomer compounds did not significantly affect the process of copolymerization or the molecular masses of the obtained copolymers. The quantity of chemically bonded naphthalimide monomer in the copolymers was determined to be over 60%. The spectral properties of the compounds and their photostability in solution and in the copolymers were studied. The influence of the compounds on the photostability of the copolymers was determined. The compounds, especially those containing a stabilizer (TMP) fragment in their molecules, showed a positive stabilizing effect on the photodegradation of poly(methyl methacrylate). Polyamide fabrics with 2‐allyl‐6‐hydrazino‐benzo[de]isoquinoline‐1,3‐dione, 2‐allyl‐6‐(2‐amino‐ethylamino)‐benzo[de]isoquinoline‐1,3‐dione, and 2‐chloro‐N′‐(2‐methyl)‐1,3‐dioxo‐2,3‐dihydro‐1H‐benzo[de] isoquinoline‐6‐yl) acetohydrazide were dyed, and materials with an intense yellow color and fluorescence were obtained. Cotton fabrics were whitened with 2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐6‐methoxy‐benzo[de]isoquinoline‐1,3‐dione, 2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐6‐allyloxybenzo[de]isoquinoline‐1, 3‐dione, and 2‐[2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐1,3‐dioxo‐2,3‐dihidro‐1H benzo [de]isoquinoline‐6‐oxy]ethyl‐2‐methacrylate, and materials with bright whiteness and intense bluish fluorescence were obtained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Combustion behavior and application of polyolefin‐based floor sheet laminated with Nylon‐6/clay nanocomposites film

Nanocomposites are potential materials that can be used to improve the flame resistance of polymers without the need for halogen‐based flame retardants. However, the nanocomposites cannot be used as the only raw material to produce final products as they are too expensive compared with low‐cost commodity plastics. Therefore, some types of polyolefin‐based floor sheet laminated with nanocomposites film were prepared for the cone calorimetric study to determine the suitable nanocomposites laminated structure for flame resistance. This study found that the polyolefin‐based floor sheet laminated with 200 µm Nylon‐6/montmorillonite nanocomposites film on the surface can reduce the HRR _max and the S significantly; other types of nanocomposites film‐laminated floor sheet were not able to reduce their flame resistance in comparison with the normal Nylon‐6 film‐laminated floor sheet. Meanwhile, based on the gas barrier performance, the higher aspect ratio of clay is assumed to contribute to the higher flame resistance of nanocomposites. Thus, the polyolefin‐based floor sheet laminated with Nylon‐6/sericite nanocomposites film on the surface was also prepared and examined in the cone calorimetric study. However, the Nylon‐6/sericite nanocomposites film surface‐laminated floor sheet did not cause a significant reduction in the HRR _max and S compared with the Nylon‐6/montmorillonite nanocomposites film surface‐laminated floor sheet. The grade determined according to the standard fire test and the mechanical properties of the Nylon‐6/montmorillonite nanocomposites film surface‐laminated floor sheet satisfied the requirements for floor sheets for Japanese railway vehicles. Copyright © 2010 John Wiley & Sons, Ltd.     

Comparison of the antibacterial activity of modified‐cotton with magainin I and LL‐37 with potential as wound‐dressings

Wounds are the ideal setting for the development of micro‐organisms, so it is often necessary to apply a dressing to control bacterial colonization. Cotton is commonly used in dressings, as it exhibits important hydrophilic characteristics such as high moisture and fluid retention properties, but it may provide a sustainable media for the development of micro‐organisms. In this way, the development of new strategies to provide cotton materials with lasting and effective antimicrobial properties is of the utmost importance. Consequently, here we described two processes to develop cotton‐dressings functionalized with antimicrobial peptides (AMPs) magainin I (MagI) and LL‐37, in order to give cotton‐dressings an antibacterial effect. The AMPs showed no cytotoxic effect against human fibroblasts so they are safe to contact with skin. In addition, the functionalized materials with either LL‐37 or MagI present an antimicrobial effect exhibiting inhibition ratios of 89% against Klebsiella pneumoniae and 58% against Staphylococcus aureus, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40997.