Preparation of UV-curable intercalated/exfoliated epoxide/acrylateclays nanocomposite resins

Abstract

Preparation of UV-curable intercalated/exfoliated epoxide/acrylateclays nanocomposite resins with the addition of specific monomers and solvent via the consideration of solubility parameter and chemical reactivity was carried out in this work. Due to the good compatibility with surfactant in acrylateclays and the cationic oligomer in resin matrix, the two additive monomers dispersed uniformly in resin matrix with the swollen acrylateclays before UV curing. As revealed by conversion ratio and DTG analyses, chemical bonds between the two additive monomers, the cationic oligomers and surfactant in acrylateclays were formed during UV irradiation. This, in turn, generated a hybrid acrylate-based/epoxy network and effectively enlarged the lamellae spacing of inorganic clays in nanocomposite resins prepared in this work. The XRD and TEM characterizations revealed that the intercalated clay domains containing exfoliated lamellae about 1 nm in thickness uniformly disperse in polymeric matrix. The nanocomposite resin containing 5 wt.% inorganic filler possessed the physical properties as follows: Td-5% = 213 °C, CTE = 80.5 ppm/°C, moisture absorption = 6.12%, average optical transmittance = 83.17%, and adhesion strength on glass substrate = 43.8 kgf/cm2. The analyses above indicated that the formation of polymeric interpenetrating networks and nanometer-scale exfoliation of clay lamellae not only improve the thermal properties and resistance to moisture permeation, but also retain highly optical transmittance and satisfactory adhesion strength of nanocomposite resins prepared in this work. A better device lifetime property was hence achieved when the nanocomposite resins were applied to the packaging of OLEDs.