Activation of pine kraft lignin by Fenton-type oxidation for cross-linking with oligo(oxyethylene) diglycidyl ether

Holzforschung ◽  
2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Lars Passauer ◽  
Klaus Fischer ◽  
Falk Liebner
Keyword(s):  
Ethylene Glycol ◽  
Water Sorption ◽  
Structural Changes ◽  
Kraft Lignin ◽  
Diglycidyl Ether ◽  
Fenton Oxidation ◽  
Cross Linking ◽  
Ferrous Chloride ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Abstract Mechanically stable hydrogels featuring water absorption capacities of up to 75 gH2O ggel -1 can be obtained by cross-linking of activated technical lignins with poly(ethylene) glycol diglycidyl ether under strong alkaline conditions. Fenton oxidation prior to cross-linking by hydrogen peroxide and catalytic amounts of ferrous chloride has been found to be superior to an alkaline H2O2 pre-treatment with respect to gel formation, water sorption, and rheological properties of the resulting oligo(oxyethylene) lignin gels. Purified pine kraft lignin undergoes in the course of Fenton oxidation hydroxylation of both aliphatic and aromatic moieties. This is the main reason for the enhanced cross-linking density obtained after treatment with poly(ethylene) glycol diglycidyl ether. The oxidative changes have been demonstrated by principal component analysis of Curie point pyrograms, wet chemical methods, FT-IR, and 31P NMR spectroscopy. Cleavage of side-chains, radical 5,5′-coupling of phenylpropane units, formation of carbonyl and carboxyl groups, and cleavage of aromatic rings were observed. These structural changes may increase or decrease the water sorption capability of the cross-linked products.

scholarly journals Synthesis of Network Polymers by Means of Addition Reactions of Multifunctional-Amine and Poly(ethylene glycol) Diglycidyl Ether or Diacrylate Compounds

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2047
Author(s):  
Naofumi Naga ◽  
Mitsusuke Sato ◽  
Kensuke Mori ◽  
Hassan Nageh ◽  
Tamaki Nakano
Keyword(s):  
Ethylene Glycol ◽  
Room Temperature ◽  
Addition Reaction ◽  
Monomer Concentration ◽  
Diglycidyl Ether ◽  
Porous Polymers ◽  
Addition Reactions ◽  
Poly Ethylene Glycol ◽  
Network Polymers ◽  
Poly Ethylene

Addition reactions of multi-functional amine, polyethylene imine (PEI) or diethylenetriamine (DETA), and poly(ethylene glycol) diglycidyl ether (PEGDE) or poly(ethylene glycol) diacrylate (PEGDA), have been investigated to obtain network polymers in H2O, dimethyl sulfoxide (DMSO), and ethanol (EtOH). Ring opening addition reaction of the multi-functional amine and PEGDE in H2O at room temperature or in DMSO at 90 °C using triphenylphosphine as a catalyst yielded gels. Aza-Michael addition reaction of the multi-functional amine and PEGDA in DMSO or EtOH at room temperature also yielded corresponding gels. Compression test of the gels obtained with PEI showed higher Young’s modulus than those with DETA. The reactions of the multi-functional amine and low molecular weight PEGDA in EtOH under the specific conditions yielded porous polymers induced by phase separation during the network formation. The morphology of the porous polymers could be controlled by the reaction conditions, especially monomer concentration and feed ratio of the multi-functional amine to PEGDA of the reaction system. The porous structure was formed by connected spheres or a co-continuous monolithic structure. The porous polymers were unbreakable by compression, and their Young’s modulus increased with the increase in the monomer concentration of the reaction systems. The porous polymers absorbed various solvents derived from high affinity between the polyethylene glycol units in the network structure and the solvents.

Cross-linking of cellulose and poly(ethylene glycol) with citric acid

2015 ◽  
Vol 90 ◽  
pp. 21-24 ◽  
Author(s):  
Pamela de Cuadro ◽  
Tiina Belt ◽  
Katri S. Kontturi ◽  
Mehedi Reza ◽  
Eero Kontturi ◽  
...  
Keyword(s):  
Citric Acid ◽  
Ethylene Glycol ◽  
Cross Linking ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Preparation and Properties of a Hydrolytically Stable Cyclooctyne-Containing Polymer

Synlett ◽  
2018 ◽  
Vol 29 (19) ◽  
pp. 2535-2541
Author(s):  
Alex Adronov ◽  
Kelvin Li ◽  
Stuart McNelles
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Monomethyl Ether ◽  
Phenylene Vinylene ◽  
Cross Linking ◽  
Poly Ethylene Glycol ◽  
Ethylene Glycol Monomethyl Ether ◽  
Glycol Monomethyl Ether ◽  
Poly Ethylene

A poly[(phenylene vinylene)-co-dibenzocyclooctyne] polymer prepared by Wittig polymerization chemistry between dibenzocyclooctyne bisaldehyde [DIBO-(CHO)2] and bis(triethyleneglycol)phenylbis(tributylphosphonium) dibromide is reported. The resulting polymer exhibits moderate molecular weight (Mn: 10.5 kDa, Mw: 21.3 kDa, Ð: 2.02) and is fluorescent. It could be readily functionalized by strain-promoted alkyne-azide cycloadditon with different azides, and fluorescence of the polymer was preserved after functionalization. Grafting azide-terminated 5 kDa poly(ethylene glycol) monomethyl ether chains drastically affected the solubility of the polymer. Cross-linking the polymer with poly(ethylene glycol) that was terminated at both ends with azide groups gave access to a fluorescent organogel that could be dried and reswollen with water to form a hydrogel.

Synthesis of Sulfhydryl Cross-Linking Poly(Ethylene Glycol)-Peptides and Glycopeptides as Carriers for Gene Delivery†

2002 ◽  
Vol 13 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Youmie Park ◽  
Kai Y. Kwok ◽  
Chawki Boukarim ◽  
Kevin G. Rice
Keyword(s):  
Gene Delivery ◽  
Ethylene Glycol ◽  
Cross Linking ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Dual mode gelation behavior of silk fibroin microgel embedded poly(ethylene glycol) hydrogels

2016 ◽  
Vol 4 (26) ◽  
pp. 4574-4584 ◽  
Author(s):  
S. Ryu ◽  
H. H. Kim ◽  
Y. H. Park ◽  
C.-C. Lin ◽  
I. C. Um ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Silk Fibroin ◽  
Cross Linking ◽  
Poly Ethylene Glycol ◽  
Dual Mode ◽  
Hydrogel Formation ◽  
Gelation Behavior ◽  
Poly Ethylene

Hydrogel formation by more than two cross-linking mechanisms is preferred for the sophisticated manipulation of hydrogel properties.

Enhancement of Mechanical Properties Upon Hydration in Copolymers of PEG and Iodinated Tyrosine-derived Poycarbonates

2008 ◽  
Vol 1132 ◽  
Author(s):  
F. Bedoui ◽  
L. K. Widjaja ◽  
A. Luk ◽  
D. Bolikal ◽  
N. S. Murthy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Ethylene Glycol ◽  
Ethyl Ester ◽  
Opposite Effect ◽  
Polymeric Materials ◽  
Cross Linking ◽  
Poly Ethylene Glycol ◽  
Reinforcing Effect ◽  
Poly Ethylene

ABSTRACTIncrease in modulus upon hydration in copolymers of desaminotyrosyl-tyrosine ethyl ester (DTE) and poly(ethylene glycol) (PEG) with iodinated tyrosines, poly(I2DTE-co-PEG carbonate)s, was investigated by varying the fraction and the molecular weight of the hydrophilic PEG component. Water, as expected, acts as plasticizer in polymer with PEG content < 15 wt% and > 30 wt%. But, water has the opposite effect in iodinated polymers with moderate PEG contents, between 15 to 20 wt%: it enhances the Young's modulus. The strength and modulus of hydrated poly(I2DTE-co-15%PEG2K carbonate)s increased by as much as fifteen fold upon hydration. While the decrease in the mechanical properties in most polymeric materials with diluents such water is due to the solvent-induced swelling, the increase in strength and modulus that is observed is most likely due to the reinforcing effect of the increased cross-linking efficiency of the hydrated PEG domains in the iodinated polymer.

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