High performance UV-curable polymers and polymer-clay nanocomposite thin films for advance electronic packaging applications

Radiation curable coatings based on donor-acceptor crosslinking chemistry were explored for application as a laminating layer for flexible electronic devices. The effect of unsaturated polyester backbone composition on the properties of donor-acceptor UV-cured coatings was explored. In the formulations, triethyleneglycol divinyl ether as the donor component and unsaturated polyester as the acceptor component were present at stoichiometric levels. The formulations also included a photoinitiator. The resulting coatings had a broad range of properties, which were found to correlate with the properties and compositions of the polyester backbone polymers.; UV-curable nanocomposites based on donor-acceptor crosslinking chemistry were prepared using both organo-modified and unmodified montmorillonite. The coatings were characterized for thermal, mechanical, and morphological properties. Morphological studies showed that nanocomposites were formed in all samples. Improvements were observed in glass transition temperature and modulus with the incorporation of clay. Dramatic improvement in tensile modulus was observed in the case of the modified coating as compared to the unmodified coating. Real-time IR kinetic data showed that higher conversions were obtained at higher clay loadings.; An in-situ polymerization approach was taken in order to prepare nanocomposites with an exfoliated morphology. An unsaturated polyester was synthesized in the presence of an organomodified clay and used to prepare UV-curable nanocomposite based on donor-acceptor crosslinking chemistry. This approach was aimed at the incorporation of clay into the coating in an exfoliated form. The nanocomposite containing the polyester synthesized in the presence of clay (NC_insitu) exhibited an exfoliated morphology as observed by TEM. Improvement in conversion of functional groups, significantly higher hardness value and thermal stability were observed for NC_insitu. A similar in-situ polymerization approach was used to prepare UV-curable nanocomposites based on hyperbranched polymers. Significant improvements in properties were observed with the incorporation of clay, especially in case of the nanocomposite with an exfoliated morphology.; A series of novel organomodifiers was synthesized and used to prepare organomodified clays. Properties of UV-curable coatings containing these organomodified clays were studied. Although some periodicity across properties was observed, the overall trend was that of a reduction in nanocomposite properties with an increase in the alkyl chain length of the organomodifier.