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Title: | Curing of urea- formaldehyde adhesives with collagen type hydrolsates under acid condition |
Author: | Langmaier, Ferdinand; Šívarová, Jarmila; Mládek, Milan; Kolomazník, Karel |
Document type: | Peer-reviewed article (English) |
Source document: | Journal of Thermal Analysis and Calorimetry. 2004, vol. 76, issue 3, p. 1015-1023 |
ISSN: | 1418-2874 (Sherpa/RoMEO, JCR) |
DOI: | https://doi.org/10.1023/B:JTAN.0000032286.85251.66 |
Abstract: | Condensation of dimethylol urea and its mixtures with urea or hydrolysate of chrome- tanned leather waste ( mass fraction in mixture 0.05) in presence of variable quantity of phtalic acid, as acid curing agent ( with mass fraction limits 0.01 - 0.1) was studied through TG technique. During condensation of sole dimethylol urea or its mixtures with urea, oxymethylene as well as methylene cross- links are produced at a ratio of approx. 1:1, presence of leather waste hydrolysate reduces this ratio to approx. 2:1 in favour of more stable methylene bridges. Higher concentration of phtalic acid ( above mass fraction 0.05) leads to formation of a new TG mass decrement wave in the 150 -180 oC temperature interval, which probably relates to transition of more unstable oxy-methylene bridges to more stable methylene bridges, with splitting off formadehyde. Oxy-methylene bridges may be regarded as a potential source of formaldehyde emissions by cured urea-formaldehyde adhesive films. Hydrolysates of chrome- tanned leather waste and suitable concentration of acid curing agent distinctly reduces formaldehyde emission from cured urea formaldehyde adhesive films |
Full text: | http://www.springerlink.com/content/gn845573821h22m6/ |
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