Synthesis and characterization of N‐methyl‐2,6‐dinitrodiphenylamine‐4‐diazonium salt and its diazoresin

A new photosensitive agent, dinitro derivatives of diphenylamine diazonium salt (N‐methyl‐2,6‐dinitrodiphenylamine‐4‐diazonium salt, MDNDDS), and its diazoresin were synthesized. Their photoreactivities and thermostabilities were investigated. Our results revealed that MDNDDS and MDNDDS‐resin exhibited greatly improved thermostability both in solid state and in coating film comparing with the conventional unsubstituted and mononitro substituted diphenylamine diazonium salts (DDS and MNDDS, respectively) and their diazoresins. The photosensitivity of MDNDDS was found to be slightly lower than DDS but still comparable with MNDDS. As a result of its improved thermostability, both MDNDDS‐resin as a photosensitive agent and lithographic printing plate prepared by MDNDDS‐resin will have a long shelf‐life, which is very important to reduce waste and factory running‐cost. MDNDDS also has a maximum absorption wavelength (λ_max) at 425 nm, which means that an iodine gallium lamp (main emission wavelength λ_em = 420 nm), is better than conventional mercury lamp (λ_em = 360 nm), to be used as the irradiation source in the photoimaging process. Compared with the mercury lamp, iodine gallium lamp is cheaper and greener. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

二苯胺型重氮盐在乙醇中的光,热分解

芳基重氮盐在乙醇中的光热分解已有很多研究［１～７］,但分解产物及提出的分解机理不完全统一．就一般的观点,芳基重氮盐在光热的作用下可以采取异裂或均裂的分解方式,以苯基重氮盐为例,可表示如下：式中Ｘ－为Ｃｌ,ＨＳＯ４,ＢＦ４等负离子异裂产生芳基正离子中间...     

Synthesis and characterization of 2-sulphonic diphenylamine-4-diazonium salt and its diazoresin

2-Sulphonic diphenylamine-4-diazonium salt (SDDS) and its diazoresin were synthesized and their thermal stability and photosensitivity were investigated. The results show that the thermal stability of SDDS is better than that of diphenylamine-4-diazonium salt (DDS), and is close to that of 3-methoxy-diphenylamine-4-diazonium salt (MDDS). The SDDS and its diazoresin are highly susceptible to UV light. The photoimaging behaviour of SDDS-resin was subject to a preliminary study. © 1999 Society of Chemical Industry     

Synthesis of diazoresin and its photocrosslinking reaction

Diazoresins with different specific viscosities were prepared from diphenylamine-4-diazonium salt and paraformaldehyde in concentrated sulphuric acid with different ratios of CH₂O/−N₂⁺X^-. In order to obtain a diazoresin with a specific viscosity in a given time at 0–5°C, more than a stoichiometric ratio was necessary. The photocrosslinking reaction of the diazoresins with various binder resins in solid film was investigated. The results show that the photocrosslinking reaction took place only in a system composed of diazoresin and binder resin containing −OH side-chain groups. The photodecomposition of diphenylamine-4-diazonium salt and its diazoresin in alcohol was studied. It was demonstrated that the diphenylamine aryl cation formed on decomposition is the dominant intermediate. The photocrosslinking mechanism between diazoresin and binder resin is discussed in a preliminary way. © 1998 SCI.     

Effect of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide on liquid oxygen compatibility of bisphenol a epoxy resin

In this study, bisphenol A epoxy resin (DGEBA) was chemically modified by 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), and the molecular structure of the modified epoxy resin was characterized by Fourier transform infrared spectra. The effects of DOPO on liquid oxygen compatibility of DGEBA were calculated using mechanical impact method. The results indicated that epoxy resin (EP‐P1)/4,4‐diaminobisphenol sulfone (DDS) was compatible with liquid oxygen. When compared with EP/DDS, differential scanning calorimetry and thermogravimetry analyses showed that EP‐P1/DDS and EP‐P2/DDS had much higher glass transition temperatures and char yield. X‐ray photoelectron spectroscopic analysis suggested that phosphorus atoms on the surface of EP‐P1/DDS and EP‐P2/DDS could act in the solid phase to restrain the incompatible reaction, which was in accordance with the flame‐retardant mechanism of phosphorus‐containing compounds. The compatibility mechanism of EP‐P1/DDS was further proposed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40848.     

Synthesis and characterization of tetrakis‐ derivatives of bisphenol‐A with 4‐phenylazoaniline and 5‐(4‐aminophenylazo)‐25,26,27‐tribenzoyloxy‐ 28‐hydroxycalix[4]arene

The synthesis of tetrakis‐ derivatives of bisphenol‐A containing azo groups at their 2,2′,6,6′‐positions is reported. Novel examples of bisphenol‐A, coupled with diazonium salts and derived from 4‐phenylazoaniline and 5‐(4‐aminophenylazo)‐25,26,27‐tribenzoyloxy‐28‐hydroxycalix [4]arene, have been synthesized. It has been observed that the coupling reaction of diazonium salt obtained from 4‐phenylazoaniline with bisphenol‐A gives tetrakis‐ while those derived from 5‐(4‐aminophenylazo)‐25,26,27‐tribenzoyloxy‐28‐hydroxycalix [4]arene give partially substituted bisphenol‐A analogues. The newly prepared tetrakis‐azo substituted bisphenol‐A compounds ( 1 and 2 ) are characterized by using UV‐vis, FT‐IR, ¹H‐NMR spectroscopic methods as well as elemental analysis techniques. These azo compounds give rise to bathochromic shifts in the absorption spectra, which can even be detected by “naked eye.” © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis,characterization, and properties of low viscosity tetra‐functional epoxy resin N,N,N′,N′‐ tetraglycidyl‐3,3′‐diethyl‐4,4′‐diaminodiphenylmethane

Tetra‐functional epoxy resin N,N,N′,N′‐tetraglycidyl‐3,3′‐diethyl‐4,4′‐diaminodiphenylmethane (TGDEDDM) was synthesized and characterized. The viscosity of TGDEDDM at 25°C was 7.2 Pa·s, much lower than that of N,N,N′,N′‐tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM). DSC analysis revealed that the reactivity of TGDEDDM with curing agent 4,4′‐diamino diphenylsulfone (DDS) was significantly lower than that of TGDDM. Owing to its lower viscosity and reactivity, TGDEDDM/DDS exhibited a much wider processing temperature window compared to TGDDM/DDS. Trifluoroborane ethylamine complex (BF₃‐MEA) was used to promote the curing of TGDEDDM/DDS to achieve a full cure, and the thermal and mechanical properties of the cured TGDEDDM were investigated and compared with those of the cured TGDDM. It transpired that, due to the introduction of ethyl groups, the heat resistance and flexural strength were reduced, while the modulus was enhanced. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40009.     

Interaction of diazoresins and sulfonate containing polyelectrolytes

The interaction of the photosensitive strong polycations diphenylamine‐4‐diazonium‐formaldehyde resin (DR) or 2‐nitro‐N‐methyl‐4‐diazonium‐formadehyde resin (NDR) with the sulfonate‐containing polyelectrolytes (SPE) poly(sodium vinylsulfonate) (PSV), poly(sodium‐p‐styrenesulfonate) (PSS), poly(potassium salt, 3‐sulfopropyl acrylate) (PPSA) or poly(potassium salt, 3‐sulfopropyl methacrylate) (PPSMA) has been studied. It was found that water‐insoluble DR‐based polyelectrolyte complex (i‐DR‐PEC) was formed at molar ratios (chain units) of polyanions to diazoresins of less than 1:1, but the added excessive polyanion would dissolve the i‐DR‐PEC to form water‐soluble DR‐based polyelectrolyte complex (s‐DR‐PEC). This dissolution process of PECs is related to the structure of their components: the polyanion with flexible longer side‐chain or the DR with stronger hydrophobic group exhibits high ability to dissolve the PEC. It is believed that the hydrophobic interaction between the excessive polyanion molecules and DR‐PEC chains plays a key role in the dissolution of i‐DR‐PEC. The influences of molecular weight of polyanion and concentration of NaCl on the dissolution of i‐DR‐PEC and the thermal stability of s‐DR‐PEC in excessive polyanion aqueous solution have also been investigated. © 2000 Society of Chemical Industry     

Cure kinetics of multifunctional epoxies with 2,2′‐dichloro‐4,4′‐diaminodiphenylmethane as hardener

The curing behavior of the epoxy resin N,N,N′,N′‐tetraglycidyldiaminodiphenyl methane (TGDDM) with triglycidyl p‐aminophenol as a reactive diluent was investigated using 2,2′‐dichloro‐4,4′‐diaminodiphenylmethane (DCDDM) as the curing agent. The effect of the curing agent on the kinetics of curing, shelf‐life, and thermal stability in comparison with a TGDDM‐diaminodiphenylsulfone (DDS) system was studied. The results showed a lesser activation energy at the lower level of conversion with a broader cure exotherm for the epoxy‐DCDDM system in comparison with the epoxy‐DDS system, although the overall activation energy for the two systems was comparable. TGA studies showed more stability in the epoxy‐DCDDM system than in the epoxy‐DDS system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2097–2103, 2000     

不同结构二苯胺重氮盐及重氮树脂的光，热分解

对二苯胺－4－重氮盐（DS），邻－甲氧基二苯胺－4－重氮盐（MDS）和N－甲基－间硝基二苯胺－4重氮盐（NDS）及它们的重氮树脂（DR，MDR，NDR）在水溶液中的光，热分解研究表明，这些重氮盐和树脂的光分解性质，即感光灵敏性差别不大，而热分解性质，即热稳定性差别很大，MDS的热稳定性最好，固相膜中3种树脂的光分解亦差别不大，但N－甲基－间硝基二苯胺－4－重氮树脂（NDR）固相膜的热稳定性出乎预料地好，从疏水性的角度对NDR固相膜突出的热稳定性作了初步解释。     

Influence of silica nanoparticles functionalized with poly(butyl acrylate‐co‐glycidyl methacrylate)‐g‐diaminodiphenyl sulfone on the mechanical and thermal properties of bismaleimide nanocomposites

The silica nanoparticles functionalized with poly(butyl acrylate‐co‐glycidyl methacrylate)‐g‐diaminodiphenyl sulfone (P(BA‐co‐GMA)‐g‐DDS)) were prepared via atom transfer radical polymerization and ring open reaction, and characterized by Fourier transform infrared and X‐ray photoelectron spectroscopy. Subsequently, the influence of SiO₂ content on the mechanical and thermal properties for the bismaleimide (BMI) resin nanocomposites modified with pristine SiO₂ and SiO₂‐P(BA‐co‐GMA)‐g‐DDS) was investigated. It was found that SiO₂‐P(BA‐co‐GMA)‐g‐DDS) was more effective as a modifier than pristine SiO₂. The most significant improvement of the impact strength (+108.7%) and flexural strength (+64.5%) was obtained with SiO₂‐P(BA‐co‐GMA)‐g‐DDS) at 0.5 wt% content. Moreover, the thermal properties of nanocomposites were distinctly improved with the addition of functionalized SiO₂. The reasons for these changes were discussed in this article. POLYM. COMPOS., 34:2154–2159, 2013. © 2013 Society of Plastics Engineers     

Phosphorus‐containing epoxy resin for an electronic application

A phosphorus‐containing epoxy resin, 6‐H‐dibenz[c,e][1,2] oxaphosphorin‐6‐[2,5‐bis(oxiranylmethoxy)phenyl]‐6‐oxide (DOPO epoxy resin), was synthesized and cured with phenolic novolac (Ph Nov), 4,4′‐diaminodiphenylsulfone (DDS), or dicyandiamide (DICY). The reactivity of these three curing agents toward DOPO epoxy resin was found in the order of DICY > DDS > Ph Nov. Thermal stability and the weight loss behavior of the cured polymers were studied by TGA. The phosphorus‐containing epoxy resin showed lower weight loss temperature and higher char yield than that of bisphenol‐A based epoxy resin. The high char yields and limiting oxygen index (LOI) values as well as excellent UL‐94 vertical burn test results of DOPO epoxy resin indicated the flame‐retardant effectiveness of phosphorus‐containing epoxy resins. The DOPO epoxy resin was investigated as a reactive flame‐retardant additive in an electronic encapsulation application. Owing to the rigid structure of DOPO and the pendant P group, the resulting phosphorus‐containing encapsulant exhibited better flame retardancy, higher glass transition temperature, and thermal stability than the regular encapsulant containing a brominated epoxy resin. High LOI value and UL‐94 V‐0 rating could be achieved with a phosphorus content of as low as 1.03% (comparable to bromine content of 7.24%) in the cured epoxy, and no fume and toxic gas emission were observed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 353–361, 1999     

Synthesis and properties of novel trifunctional epoxy triglycidyl of 4‐(4‐aminophenoxy)phenol with high toughness

A trifunctional epoxy containing oxyphenylene unit, triglycidyl of 4‐(4‐aminophenoxy)phenol (TGAPP) was synthesized and characterized. The chemical structure of TGAPP was confirmed with FTIR and ¹H‐NMR. DSC analysis revealed that the reactivity of TGAPP with curing agent 4, 4′‐diaminodiphenylsulfone (DDS) was significantly lower than that of triglycidyl para‐aminophenol (TGPAP). Rheological analysis showed that the processing window of TGAPP/DDS was 20°C wider compared with that of TGPAP/DDS. The thermal and mechanical properties of cured TGAPP/DDS were investigated and compared with those of the cured TGPAP/DDS. Experimental results showed that, due to the introduction of oxyphenylene unit, the heat resistance and flexural strength were slightly reduced, while the tensile strength and impact strength were enhanced. SEM also confirmed that the introduction of oxyphenylene unit could enhance the toughness of the TGAPP/DDS as evident from ridge formation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41878.     

Novel adamantane‐containing epoxy resin

A novel adamantane‐containing epoxy resin diglycidyl ether of bisphenol‐adamantane (DGEBAda) was successfully synthesized from 1,3‐bis(4‐hydroxyphenyl)adamantane by a one‐step method. The proposed structure of the epoxy resin was confirmed with Fourier transform infrared, ¹H‐NMR, gel permeation chromatography, and epoxy equivalent weight titration. The synthesized adamantane‐containing epoxy resin was cured with 4,4′‐diaminodiphenyl sulfone (DDS) and dicyandiamide (DICY). The thermal properties of the DDS‐cured epoxy were investigated with differential scanning calorimetry and thermogravimetric analysis (TGA). The dielectric properties of the DICY‐cured epoxy were determined from its dielectric spectrum. The obtained results were compared with those of commercially available diglycidyl ether of bisphenol A (DGEBA), a tetramethyl biphenol (TMBP)/epoxy system, and some other associated epoxy resins. According to the measured values, the glass‐transition temperature of the DGEBAda/DDS system (223°C) was higher than that of the DGEBA/DDS system and close to that of the TMBP/DDS system. TGA results showed that the DGEBAda/DDS system had a higher char yield (25.02%) and integral procedure decomposition temperature (850.7°C); however, the 5 wt % degradation temperature was lower than that of DDS‐cured DGEBA and TMBP. Moreover, DGEBAda/DDS had reduced moisture absorption and lower dielectric properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Thermal characterization of carbon‐nanofiber‐reinforced tetraglycidyl‐4,4′‐diaminodiphenylmethane/4,4′‐diaminodiphenylsulfone epoxy composites

The thermal properties of carbon nanofibers (CNF)/epoxy composites, composed of tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM) resin and 4,4′‐diaminodiphenylsulfone (DDS) as a curing agent, were investigated with differential scanning calorimetry (DSC), thermogravimetric analysis, and dynamic mechanical thermal analysis. DSC results showed that the presence of CNF had no pronounced influence on the heat of the cure reaction. However, the incorporation of CNF slightly improved the thermal stability of the epoxy. Furthermore, the storage modulus of the TGDDM/DDS epoxy was significantly enhanced, whereas the glass‐transition temperature was not significantly affected, upon the incorporation of CNFs. The storage modulus of 5 wt % CNF/epoxy composites at 25°C was increased by 35% in comparison with that of the pure epoxy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 295–298, 2006     

Studies on isotactic poly(phenyl glycidyl ether)‐modified epoxy resins. II. Toughening of epoxy resins

A semicrystalline polymer, isotactic poly(phenyl glycidyl ether) (i‐PPGE) was used as a modifier for epoxy resin; 1,8‐Diamino‐p‐methane (MNDA) and 4,4′‐Diamino diphenyl sulfone (DDS) were used as curing agents. In the MNDA‐cured resins, the dispersed phase were spherical particles with diameters in the range of 0.5–1.0 μm when the resin was blended with 5 phr i‐PPGE. In the DDS‐cured resins, the particle size distribution of the dispersed phase was much wider. The difference was traced back to the reactivity of the curing agent and the different regimes used for curing. Through dynamic mechanical analysis, it was found that in the MNDA‐cured systems, i‐PPGE had a lower crystallinity than in the DDS‐cured system. In spite of the remarkable difference in the morphology and microstructure of the modified resins cured with these two curing agents, the toughening effects of i‐PPGE were similar for these resins. The critical stress intensity factor (K_IC) was increased by 54% and 53%, respectively, for the resins cured by DDS and by MNDA, blending with 5 phr of the toughner. i‐PPGE was comparable with the classical toughners carboxyl‐terminated butadiene‐acrylonitrile copolymers in effectiveness of toughening the epoxy resin. An advantage of i‐PPGE was that the modulus and the glass‐transition temperature of the resin were less affected. However, this modifier caused the flexural strength to decrease somewhat. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1223–1232, 2002; DOI 10.1002/app.10445     

Curing kinetics and reaction‐induced homogeneity in networks of poly(4‐vinyl phenol) and diglycidylether epoxide cured with amine

Mixtures of diglycidyl ether of bisphenol‐A (DGEBA) epoxy resin with poly(4‐vinyl phenol) (PVPh) of various compositions were examined with a differential scanning calorimeter (DSC), using the curing agent 4,4′‐diaminodiphenylsulfone (DDS). The phase morphology of the cured epoxy blends and their curing mechanisms depended on the reactive additive, PVPh. Cured epoxy/PVPh blends exhibited network homogeneity based on a single glass transition temperature (T_g) over the whole composition range. Additionally, the morphology of these cured PVPh/epoxy blends exhibited a homogeneous network when observed by optical microscopy. Furthermore, the DDS‐cure of the epoxy blends with PVPh exhibited an autocatalytic mechanism. This was similar to the neat epoxy system, but the reaction rate of the epoxy/polymer blends exceeded that of neat epoxy. These results are mainly attributable to the chemical reactions between the epoxy and PVPh, and the regular reactions between DDS and epoxy. Polym. Eng. Sci. 45:1–10, 2005. © 2004 Society of Plastics Engineers.     

Synthesis of novel polyimides containing side‐chain azo‐2‐naphthol moieties

An amine‐ester derivative of isoeugenol was prepared in three steps. This amine‐ester was converted to diazonium salt and subsequently was reacted with 2‐naphthol and a novel isoeugenol ester‐azo derivative as a new monomer was obtained in quantitative yield. This monomer was characterized by high‐field ¹H‐NMR, IR, and elemental analysis and then was used for the preparation of model compound and polymerization reactions. 4‐Phenyl‐1,2,4‐triazoline‐3,5‐dione was allowed to react with this new monomer. The reaction was very fast and gave only one double adduct by Diels–Alder and ene pathways in excellent yield. The polymerization reactions of novel monomer with bistriazolinediones [bis(p‐3,5‐dioxo‐1,2,4‐triazolin‐4‐ylphenyl)methane and 1,6‐bis(3,5‐dioxo‐1,2,4‐triazolin‐4‐yl)hexane] were carried out in N,N‐dimethylacetamide at room temperature. The reactions were exothermic, fast, and gave novel heterocyclic polyimides by repetitive Diels–Alder‐ene polyaddition reactions. Some structural characterization and physical properties of these novel heterocyclic polyimides are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1942–1951, 2003     

Electropolymerisation and characterisation of nanosize conducting poly[(o‐chloroaniline)‐co‐(4,4′‐diaminodiphenylsulfone)] on a polyaniline‐modified electrode

An exciting methodology for the electrosynthesis of poly(o‐chloroaniline) is proposed, based on the electrochemical polymerisation of o‐chloroaniline (OCA) on a polyaniline‐modified electrode and copolymerisation of OCA with different compositions of biologically important 4,4′‐diaminodiphenylsulfone (DDS) on the same electrode. The copolymer electrosynthesised from an equimolar feed composition of OCA and DDS behaved the best among the other compositions employed for polymerisation. The UV‐visible and Fourier transform infrared spectral data obtained for this copolymer suggest the incorporation of DDS in the polymer chain. The X‐ray diffraction profile of the copolymer indicates a substantial amorphous nature of the as‐synthesised copolymer. Scanning electron micrographs recorded for the homo‐ and copolymer reveal distinctly different morphologies. The average grain size of the prepared copolymer as approximated from the micrographs is 80 nm. The procedure reported is found to be a very efficient method for electrochemically polymerising pristine OCA and poly(OCA‐co‐DDS) and the adopted strategy is the best so far reported for the electrochemical polymerisation of OCA on any electrode surface. Copyright © 2009 Society of Chemical Industry     

Synthesis and characterization of 3-methoxydiphenylamine-4-diazonium salt and its diazoresin

3-Methoxydiphenylamine-4-diazonium salt (MDDS) and its diazoresin were synthesized. The photo- and thermal decomposition of salt and the resins were investigated. The results show that MDDS exhibits excellent thermostability as well as high photosensitivity. A series of diazoresins with different organic counteranions, which dissolve in common solvents and usually were chosen to manufacture the negative presensitized plate, were also synthesized The kinetics of the photo- and thermal decomposition of MDDS in ethanol is reported. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1975–1982, 1998