Preparation and properties of exfoliated nanocomposites through intercalated a photoinitiator into LDH interlayer used for UV curing coatings

The exfoliated polymer/layered double hydroxide (LDH) nanocomposites based on MgAl were prepared through intercalating a photoinitiator into LDH interlayer, following by UV irradiation induced polymerization. The fragmental photoinitiator, 2-hydroxy-2-methyl-1-phenylpropane-1-one (1173) firstly reacted with isophorone diisocyanate (IPDI) to obtain the semiadduct, 1173-IPDI, and then reacted with the LDH modified by aminoundecanoic acid, obtaining LDH-1173 with an intercalated microstructure, which was characterized by FTIR, XRD, and TGA measurements. The obtained LDH-1173 was mixed with the multifunctional acrylate oligomer and monomer, and then exposed to a UV lamp to prepare a polymer/LDH nanocomposite. From the XRD, TEM and HR-TEM analysis, as well the photopolymerization kinetics investigation, it was found that the LDH-1173 effectively initiated the photopolymerization of acrylates, and formed exfoliated polymer/LDH nanocomposites. However, the mostly intercalated polymer/LDH nanocomposites were obtained for the systems with additional 1173 except for LDH-1173 addition. Compared with the pure polymer material, both the exfoliated and intercalated polymer/LDH nanocomposites exhibited the enhancements in mechanical and thermal properties, as well as hardness.