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Kristiina Aaltokorte - One of the best experts on this subject based on the ideXlab platform.
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occupational contact dermatitis caused by 1 3 benzenedimethanamine n 2 phenylethyl derivatives in Hardeners for epoxy paints and coatings
Contact Dermatitis, 2016Co-Authors: Maria Pesonen, Outi Kuuliala, Sari Suomela, Kristiina AaltokorteAbstract:SummaryBackground Amines in epoxy Hardeners are significant causes of occupational allergic contact dermatitis among workers who use epoxy resin systems. Objectives To describe a novel group of contact allergens: N-(2-phenylethyl) derivatives of the reactive amine 1,3-benzenedimethanamine (1,3-BDMA). Methods We describe the clinical examinations and exposure of 6 patients with occupational contact allergy to derivatives of 1,3-BDMA. Results Of the 6 patients, 4 were spray painters who used epoxy paints, 1 was a floor layer who handled a variety of epoxy coatings, and 1 was a worker in epoxy hardener manufacture. We were able to confirm exposure to epoxy Hardeners that contained derivatives of 1,3-BDMA in 5 of the 6 sensitized patients. Despite the close structural resemblance between derivatives of 1,3-BDMA and m-xylylenediamine (MXDA), only 3 patients reacted positively to MXDA. Concomitant contact allergy to diglycidyl ether of bisphenol A resin was seen in 2 of the 6 patients. Conclusions Because of the lack of a commercially available patch test substance, the diagnosis of contact allergy to derivatives of 1,3-BDMA requires patch testing with either the epoxy hardener product or a hardener ingredient that contains the derivatives of 1,3-BDMA.
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contact allergy to epoxy Hardeners
Contact Dermatitis, 2014Co-Authors: Kristiina Aaltokorte, Outi Kuuliala, Katri Suuronen, Majlen Henrikseckerman, Riitta JolankiAbstract:Summary Background Diglycidylether of bisphenol A resin is the most important sensitizer in epoxy systems, but a minority of patients develop concomitant or solitary contact allergy to epoxy Hardeners. At the Finnish Institute of Occupational Health, several in-house test substances of epoxy Hardeners have been tested in a special epoxy compound patch test series. Objectives To analyse the frequency and clinical relevance of allergic reactions to different epoxy Hardeners. Methods Test files (January 1991 to March 2013) were screened for contact allergy to different epoxy Hardeners, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. Results The most commonly positive epoxy Hardeners were m-xylylenediamine (n = 24), 2,4,6-tris-(dimethylaminomethyl)phenol (tris-DMP; n = 14), isophorone-diamine (n = 12), and diethylenetriamine (n = 9). Trimethylhexamethylenediamine (n = 7), tetraethylenepentamine (n = 4), and triethylenetetramine (n = 2) elicited some reactions, although most patients were found to have no specific exposure. Allergic reactions to hexamethylenetetramine, dimethylaminopropylamine and ethylenediamine dihydrochloride were not related to epoxy products. Conclusions Tris-DMP is an important sensitizer in epoxy Hardeners, and should be included in the patch test series of epoxy chemicals.
Yixian Gong - One of the best experts on this subject based on the ideXlab platform.
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quantification of anhydride groups in anhydride based epoxy Hardeners by reaction headspace gas chromatography
IEEE Journal of Solid-state Circuits, 2017Co-Authors: Weiqi Xie, Yixian GongAbstract:We demonstrate a reaction headspace gas chromatographic method for quantifying anhydride groups in anhydride-based epoxy Hardeners. In this method, the conversion process of anhydride groups can be realized by two steps. In the first step, anhydride groups in anhydride-based epoxy Hardeners completely reacted with water to form carboxyl groups. In the second step, the carboxyl groups reacted with sodium bicarbonate solution in a closed sample vial. After the complete reaction between the carboxyl groups and sodium bicarbonate, the CO2 formed from this reaction was then measured by headspace gas chromatography. The data showed that the reaction in the closed headspace vial can be completed in 15 min at 55°C, the relative standard deviation of the reaction headspace gas chromatography method in the precision test was less than 3.94%, the relative differences between the new method and a reference method were no more than 9.38%. The present reaction method is automated, efficient and can be a reliable tool for quantifying the anhydride groups in anhydride-based epoxy Hardeners and related research.
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quantification of the amine value in aliphatic amine epoxy Hardeners by using a reaction based headspace gas chromatographic technique
Analytical Methods, 2017Co-Authors: Weiqi Xie, Yixian GongAbstract:This paper reports an automated method for quantifying the amine value in aliphatic amine epoxy Hardeners by reaction-based headspace gas chromatography. After aliphatic amine epoxy Hardeners reacted with hydrochloric acid solution, the remaining hydrochloric acid was transferred to the headspace vial that contains sodium bicarbonate solution. After the complete reaction between the remaining hydrochloric acid and sodium bicarbonate, the carbon dioxide generated from the reaction was then detected by using headspace gas chromatography. The data showed that the reaction in the closed headspace vial can be completed in 10 min at 65 °C. The relative standard deviation of the reaction-based HS-GC method in the precision test was less than 2.78%, and the relative differences between the present method and the reference back-titration method were no more than 6.96%. The present reaction-based method is automated and efficient and can be a reliable tool for quantifying the amine value in aliphatic amine epoxy Hardeners and related research.
Riitta Jolanki - One of the best experts on this subject based on the ideXlab platform.
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contact allergy to epoxy Hardeners
Contact Dermatitis, 2014Co-Authors: Kristiina Aaltokorte, Outi Kuuliala, Katri Suuronen, Majlen Henrikseckerman, Riitta JolankiAbstract:Summary Background Diglycidylether of bisphenol A resin is the most important sensitizer in epoxy systems, but a minority of patients develop concomitant or solitary contact allergy to epoxy Hardeners. At the Finnish Institute of Occupational Health, several in-house test substances of epoxy Hardeners have been tested in a special epoxy compound patch test series. Objectives To analyse the frequency and clinical relevance of allergic reactions to different epoxy Hardeners. Methods Test files (January 1991 to March 2013) were screened for contact allergy to different epoxy Hardeners, and the clinical records of patients with allergic reactions were analysed for occupation, concomitant allergic reactions, and exposure. Results The most commonly positive epoxy Hardeners were m-xylylenediamine (n = 24), 2,4,6-tris-(dimethylaminomethyl)phenol (tris-DMP; n = 14), isophorone-diamine (n = 12), and diethylenetriamine (n = 9). Trimethylhexamethylenediamine (n = 7), tetraethylenepentamine (n = 4), and triethylenetetramine (n = 2) elicited some reactions, although most patients were found to have no specific exposure. Allergic reactions to hexamethylenetetramine, dimethylaminopropylamine and ethylenediamine dihydrochloride were not related to epoxy products. Conclusions Tris-DMP is an important sensitizer in epoxy Hardeners, and should be included in the patch test series of epoxy chemicals.
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occupational allergic contact dermatitis caused by 2 4 6 tris dimethylaminomethyl phenol and review of sensitizing epoxy resin Hardeners
International Journal of Dermatology, 1996Co-Authors: Lasse Kanerva, Tuula Estlander, Riitta JolankiAbstract:Background. Epoxy resin compounds (ERG) include a large number of sensitizing chemicals such as epoxy resins (ER), Hardeners (curing agents), and reactive diluents. Allergic contact dermatitis (ACD) caused by ERCS is often occupational. Materials and Methods. We report a patient, sensitized to a hardener of a two-component epoxy paint. Three conventional patch test sessions were performed to diagnose the causative chemical. We also review the literature on sensitizing epoxy-resin Hardeners. Results. A 47-year-old nonatopic woman developed dermatitis from a two-component epoxy paint. Patch testing with epoxy resin was negative, but 2,4,6–tris(dimethylaminomethyl)phenol (tris-DMP), used in the paint hardener, induced an allergic patch test reaction. We also review briefly other epoxy Hardeners that have caused allergic dermatitis, including: (1) aliphatic polyamines, e.g., ethylenediamine, diethylenetriamine, triethylenetetramine, 3-dimethylaminopropylamine, and trimethylhexamethylenediamine; (2) cycloaliphatic polyamines, e.g., isophoronediamine and 3,3′-dimethyl-4,4-diaminodicyclohexylmethane; (3) aromatic amines, such as 4,4′-diaminodiphenylmethane, m-phenylene diamine, and 1,3-xylylene diamine; (4) dicyanodiamide; (5) triglycidyl isocyanurate, an epoxy compound that may be used as an epoxy-resin hardener; and (6) additives in epoxy accelerators, such as hexavalent chromate. Conclusions. No one chemical can be used to screen for sensitization to the many different epoxy Hardeners. Extensive patch testing may be required to reveal the hardener that has caused the allergy. The hardener, 2,4,6-tris-dimethylaminomethyDphenol (tris-DMP), is a new sensitizer. To verify ACD caused by tris-DMP, patch-testing at 1% in petrolatum is suggested.
David Koh - One of the best experts on this subject based on the ideXlab platform.
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allergic contact dermatitis from resin Hardeners during the manufacture of thermosetting coating paints
Contact Dermatitis, 1992Co-Authors: I Foulds S And, David KohAbstract:5 production operators from 2 factories manufacturing thermosetting coating paint developed work-related skin disorders within 12 months of the introduction of a new powdered paint product. All 5 workers were found to have allergic contact dermatitis from 2 epoxy resin Hardeners, both of which were commercial preparations of triglycidyl isocyanurate (TGIC). 2 of the workers had concomitant sensitization to epoxy resin in the standard series and several of the epoxy resin preparations at the workplace. TGIC has been reported as a contact sensitizer both in persons producing the chemical and among end-users of TGIC-containing products. These 5 reported cases document allergic contact dermatitis from commercial TGIC among exposed workers during an intermediate process of powdered paint manufacture. The possibility of substituting this epoxy resin hardener with less sensitizing alternatives should be explored.
Ana C Fonseca - One of the best experts on this subject based on the ideXlab platform.
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preparation of fully biobased epoxy resins from soybean oil based amine Hardeners
Industrial Crops and Products, 2017Co-Authors: Celia F Frias, Armenio C Serra, A Ramalho, Jorge F J Coelho, Ana C FonsecaAbstract:Abstract This work reports a straigthforward method for the preparation of soybean oil based amine derivatives to be used as green Hardeners for epoxy resins. The Hardeners were synthesized by the Michael-addition reaction of acrylated soybean oil (AESO) with different diamines, viz . 1,6-hexamethylene diamine (HMDA), trans -1,4-cyclohexylamine (TCHMDA) and L -lysine methyl ester hydrochloride (LYS). The reaction proceeded under mild conditions and the products were obtained with high yields. The amine biobased Hardeners were successfully crosslinked with ESO, affording soybean oil based thermosets (SOTs). The SOTs were characterized in terms of thermomechanical properties, swelling capacity, in vitro hydrolytic degradation. The results allowed to establish important structure/properties relationships between the materials and methods used and the performance of the SOTs. This work could be used as proof-of-concept to enlarge the vast range of applications that employ amine curing.
