| 초록 |
The silanol groups of silica particle have been chemically modified for the covalent funtionalization. The nano-size silica particles were functionalized with vinyl isocyanate and subsequently UV cured to synthesize the polyurethane-silica nanocomposites which were tested for mechanical, dynamic mechanical, thermalmechanical cycle, and crosslink density. It was found that simple addition of silica particles disturb the cure kinetics of urethane acrylate, aside from the particle reinforcement, giving rise to the decreased tensile strength below the unfilled one, whereas modified silica provides the composites with crosslinks which are pinned at the silica surfaces and effectively reinforces the materials mechanically. With addition of silica particles to polymer chains, shape fixability was largely increased whereas recoverability was decreased. |
