Hyperbranched urethane-acrylates

Abstract

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 α-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

A novel UV‐curable epoxy acrylate resin containing arylene ether sulfone linkages: Preparation, characterization, and properties

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Colour and gloss properties of pigment‐printed synthetic leather using an ultraviolet‐curable water‐borne polyurethane acrylate binder and two photoinitiators at different ratios

“…The decrease in the final C=C double bond after exposure to UV irradiation determines the properties of UV‐crosslinked films. The increase in the polymerisation during curing leads to an increase in the strength of the crosslinked film structure .…”

Modifications and applications of hyperbranched aliphatic polyesters based on dimethylolpropionic acid

“…UV‐curable hyperbranched urethane‐acrylate coatings prepared from HBPE and poly(ethylene glycol) acrylate showed excellent mechanical properties (hardness and flexibility) and solvent resistance 70. Through the combination of HBPE modified with unsaturated fatty acids (or saturated fatty acids) and an acrylate‐isocyanate adduct, hyperbranched urethane‐acrylate resins were obtained with very low viscosity 71, 72.…”