Volltext-Downloads (blau) und Frontdoor-Views (grau)
The search result changed since you submitted your search request. Documents might be displayed in a different sort order.
  • search hit 57 of 1589
Back to Result List

Unmodified kraft lignin isolated at room temperature from aqueous solution for preparation of highly flexible transparent polyurethane coatings

  • Polyurethane (PU) coatings were successfully produced using unmodified kraft lignin (KL) as an environmentally benign component in contents of up to 80 wt%. Lignin samples were precipitated from industrial black liquor in aqueous solution working at room temperature and different pH levels (pH 2 to pH 5). Lignins were characterized by UV-Vis, FTIR, pyrolysis-GC/MS, SEC and 31P-NMR. Results show a correlation between pH level, OH number and molecular weight Mw of isolated lignins. Lignin-based polyurethane coatings were prepared in an efficient one step synthesis dissolving lignin in THF and PEG425 in an ultrasonic bath followed by addition of 4,4-diphenylmethanediisocyanate (MDI) and triethylamine (TEA). Crosslinking was achieved under very mild conditions (1 hour at room temperature followed by 3 hours at 35 °C). The resulting coatings were characterized regarding their physical properties including ATR-IR, TGA, optical contact angle, light microscopy, REM-EDX and AFM data. Transparent homogeneous films of high flexibility resulted from lignins isolated at pH 4, possessing a temperature resistance up to 160 °C. Swelling tests revealed a resistance against water. Swelling in DMSO depends on index, pH of precipitation and catalyst utilization for PU preparation. According to AFM studies, surface roughness is between 10 and 28 nm.

Download full text files

Export metadata

Additional Services

Search Google Scholar Check availability

Statistics

Show usage statistics
Metadaten
Document Type:Article
Language:English
Author:Stephanie Elisabeth Klein, Jessica Rumpf, Peter Kusch, Rolf Albach, Matthias Rehahn, Steffen Witzleben, Margit Schulze
Parent Title (English):RSC Advances
Volume:8
Issue:71
First Page:40765
Last Page:40777
ISSN:2046-2069
URN:urn:nbn:de:hbz:1044-opus-43290
DOI:https://doi.org/10.1039/C8RA08579J
PMID:https://pubmed.ncbi.nlm.nih.gov/35557904
Publisher:Royal Society of Chemistry (RSC)
Publishing Institution:Hochschule Bonn-Rhein-Sieg
Date of first publication:2018/12/10
Copyright:This journal is © The Royal Society of Chemistry 2018. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
Funding:This research was supported by the Federal Ministry of Education and Research (BMBF) program "IngenieurNachwuchs" project LignoBau (03FH013IX4).
Departments, institutes and facilities:Fachbereich Angewandte Naturwissenschaften
Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE)
Projects:LignoBau - IngenieurNachwuchs 2014: Lignin-basierte Polymere für bauchemische Anwendungen (DE/BMBF/03FH013IX4,13FH013IX4)
Dewey Decimal Classification (DDC):5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften
Entry in this database:2019/01/08
Licence (German):License LogoCreative Commons - CC BY - Namensnennung 3.0