scholarly journals Hyperbranched urethane-acrylates

2004 ◽  
Vol 58 (11) ◽  
pp. 505-513 ◽  
Author(s):  
Srba Tasic ◽  
Branislav Bozic ◽  
Branko Dunjic
Keyword(s):  
Uv Curing ◽  
Uv Curable ◽  
Oxygen Inhibition ◽  
Alkyl Acrylates ◽  
Alkyl Acrylate ◽  
End Groups ◽  
Cross Links ◽  
Poly Ethylene Oxide ◽  
The Cross ◽  
Poly Ethylene

The synthesis, characterization and UV-curing of hyperbranched urethaneacrylates (HB-UA) were investigated in this study. They were evaluated as oli-gomers in model UV curable coatings. HB-UAs were synthesized by reaction of an aliphatic hyperbranched polyester of the second generation (HBRG2) and an isocyanate adduct, obtained by the reaction of isophoronediisocyana-te and different hydroxy alkyl acrylates. Their thermal properties and viscosities depend on the degree of modification of HBRG2 and the type of hydroxy alkyl acrylate used. The introduction of a flexible alkoxylated spacer between the HBP core and acrylate end groups reduces steric hindrance by moving the cross linkable acrylate groups away from the HBP core and increase its reactivity. Due to the presence of abstractable H-atoms in the ?-position to the ether links, HB-UAs based on poly(ethylene oxide) monoacrylate are very reactive and do not show oxygen inhibition. The obtained coatings combine a high cross linking density with flexible segments between the cross links, which results in a good compromise between hardness and flexibility and have the potential to be used in different UV-curing applications.

Synthesis of Poly(ethylene oxide)s with 1,2,4-Triazol-4-yl End Groups– Macroligands for Bistable Metal-Polymer Complexes

2004 ◽  
Vol 25 (9) ◽  
pp. 911-915 ◽  
Author(s):  
Robert Saf ◽  
Gerald Schwarzenbacher ◽  
Christian Mirtl ◽  
Gertraud Hayn ◽  
Josefine Hobisch ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Polymer Complexes ◽  
End Groups ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Metal Polymer

Characterization of Hyaluronic Acid-Poly(Ethylene Oxide) Hydrogel Dependent upon Poly(Ethylene Oxide)

2007 ◽  
Vol 342-343 ◽  
pp. 749-752
Author(s):  
Mi Sook Kim ◽  
Yoon Jeong Choi ◽  
Gun Woo Kim ◽  
In Sup Noh ◽  
Yong Doo Park ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Ethylene Oxide ◽  
Thiol Groups ◽  
Molecular Weights ◽  
Hydrogel Network ◽  
End Groups ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Surface Morphologies

Characterization of an hyaluronic acid (HA)-poly(ethylene oxide) (PEO) hydrogel was performed by changing the number of side arms in a PEO molecule. Verification of grafting chemistry and mechanical strength, as well as swelling behaviors and surface morphologies of the HA-PEO hydrogels were analyzed by employing different x-linking molecular weights (MW) of PEO ranging from 1.7 to 5.0 kDa at a fixed low MW HA in the hydrogel network. Methacrylation to the HA successfully obtained via Michael type reaction between the methacrylate arm groups in HA and the thiol end groups in PEO was observed by XPS. Hydrogel formation was markedly dependent upon the numbers of thiol groups in the PEO molecule. Furthermore the lower MW PEO-based HA hydrogel demonstrated stronger mechanical properties but lower water absorption and the smaller pore sizes on its surface and cross section.

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