실리카 나노 입자를 이용한 아미드-이미드 공중합물의 합성과 성질에 관한 연구

Abstract

Silica nano-particles are widely used in various industries because they are readily and widely available. These qualities are highly dependent on particle size and size distribution. It is an inconvenience for silica nano-particles to dry again when using it in that they cohere each other through moisture in the air. Acrylamide groups were introduced to improve a cohesiveness and copolymerized with silica nano-particles. Polyacrylamide with siloxane group copolymerized again with poly(amic acid) in order to increase thermal characteristic and their solubility. In this study, the amide group was introduced at the end group rather than the main chain, and 3-mercaptopropyl modified silica nanoparticles, which are silica nano-particles containing amide groups, were copolymerized with acrylamide monomer. The thermal and physical properties of the polyamide-imide synthesized by copolymerization using an amine compound as a catalyst and a bromine derivative were examined. Covalent bonding of the self-assembled monolayer on the surface of the prepared ultra-fine silica paticle was confirmed by morphology analysis and showed that the amide group effectively prevented a cohesiveness. Synthesis and properties of prepared intermediates(yield 86∼93%) and polymers(yield 76.4∼83.5%) by DABCO and a bromine derivative was confirmed with EA, FT-IR, TGA, XPS, XRD, SEM and others. The copolymerization of amide groups was confirmed by surface analysis of the intermediates prepared with silica and acrylic amide monomers. X-ray analysis of poly(amic acid) and poly(amic acid) containing the bromine derivative to assist in the atom transfer radical polymerization showed that bromine was graft-polymerized. The polymerized materials using tertiary amines were identified and their properties were investigated by various analyzes. DSC analysis confirmed that siloxane-amide-imide block copolymers have three Tg values. It was also found that prepared copolymers have excellent thermal stabilities through TGA analysis and thermal stabilities were affected by synthesis using ATRP. In the solubility test for the solvent, it was confirmed that the strong imide group and the siloxane segment at the end group of the copolymer had an influence on the solubility, and the solvation in the polar solvent NMP showed strong hygroscopicity in the para-para imide copolymer. Moreover, as the contact angle was reduced by such solvation, it is expected that they can be used as a substrate for electronic materials.