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Water-dispersible urethane acrylate anionomers (UAAs) were prepared using anionic dimethylol propionic acid and silica emulsion was prepared by a sol-gel process using poly(vinyl pyrrolidone) and tetraethoxysilane. The above two emulsions were mixed, and UAA/silica composite gels were prepared. FTIR, X-ray diffraction, SEM, and AFM were used to verify the structure and the inclusion of silica in the composite gels. To investigate the influence of silica in UAA gels on the physical properties, the tensile strength and elongation at break were measured, and the annealing effect was evaluated by the physical properties. As the silica content increased, the tensile strength of the composite gels increased; however, up to a certain amount of silica, phase separation was induced and physical properties were reduced.

Polyurethane acrylate anionomer (PUAA)/silica composite gels were prepared by the sol-gel reaction of tetraethoxysilane (TEOS) and methacryloxypropyl trimethoxysilane (MPTS) incorporated to PUAA gels by using a swelling method. The formation and structure of composites were confirmed by FTIR, X-ray diffraction, and SEM. As a result, we found that silica components in composites are located within the ionic domains of their gels and interacted with PUAA via hydrogen bonding. This drastically enhanced the mechanical properties of the composites. Mechanical properties are also improved by MPTS, because MPTS improves the dispersibility and adhesion of silica components in PUAA/silica composite gels.

Polymer‐dispersed liquid crystal (PDLC) films were synthesized by the copolymerization of liquid crystalline polymer (LCP) precursor, urethane acrylate (UA), and mesogenic monomer (AI) at different conditions. The morphology of polymer matrix changed with the weight ratio of polymer/liquid crystal (LC) ratio and curing temperature, resulting in a large change in the droplet size of LC domains in the PDLC film. The components used in the synthesis of polymer matrix, that is, the weight ratio of LCP, AI, and UA, also strongly influenced the morphology of PDLC films. A small amount of LCP was copolymerized with UA and AI in the preparation of polymer matrix to improve the electrooptical properties such as the viewing angle. Added LCP also affected the morphology and the properties of PDLC. The hydrophobicity of LCP caused changes in the droplet size of LC domain in PDLC films and the anchoring energy between matrix polymer and LC droplets. As the hydrophobicity of the matrix increases, the droplet size of LC domain also increases; on the contrary, anchoring energy decreased, leading to the decrease of driving voltage. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3178–3188, 2000