Wet-end additives: dielectric properties of cyanoethylated polyvinyl alcohol.

APPLICATION: Cyanoethylation is an effective method for improving the dielectric properties of PVA, which can be used as a surface size for electrical insulating paper.

Electrical insulating paper is used for making electrical products like condensers, circuits, batteries, transformers, and cables. High standards have to be met in the production of this grade, with attention to the dielectric characteristics, the electrical resistance, and the breakdown strength.

In working to improve the dielectric properties of these specialty papers, we focused on the use of a surface size based on polyvinyl alcohol. The PVA was cyanoethylated to increase its dielectric properties. Acrylonitrile was used to carry out the cyanoethylation reaction with sodium hydroxide as the catalyst. The extent of the reaction was proportional to the acrylonitrile concentration and the reaction time, as was the dielectric constant.

The cyanoethylated PVA was structurally stable, showing good physical properties and good thermal stability. Cyanoethylated PVA could be used in developing highly specialized papers for electrical insulation. View this paper online at http://www.tappi.org/index.asp?pid=32228&ch=1

Man Seok Seo is a graduate student and Hak Lae Lee is a professor with the Program in Environmental Materials Sciences, Dept. of Forest Sciences, College of Agriculture and Life Sciences, at Seoul National University, Seoul, Korea. Email Lee at [e-mail].