TECHNOLOGY OVERVIEW
The KiON family of polymers, based on silazane chemistry, has been developed to provide cost effective solutions in a variety of applications where, to date, competitive materials have fallen short. In the past, polysilazanes have been available from a number of companies; however, these polymers were typically high-priced, difficult to use, and in short supply.
In its KiON polymers, KiON Specialty Polymers is now offering inexpensive, "user friendly" polysilazanes that have demonstrated utility in ceramic coatings, and ceramic composite applications, and Polysilazane clear coats.
What Are KiON Polymers?
KiON polymers are a condensed form of polysilazane, in which cyclosilazane rings are bonded in such a way as to give extended two dimensional character through a fused cyclic structure. This differs from prior art polysilazanes that, typically, have had linear or cyclolinear structure. While not compromising solubility or other desirable processing characteristics, the condensed structure of KiON provides very high char yield in applications where KiON is used as a pre-ceramic polymer.
KiON polymers are typically provided in liquid form. In liquid form, polymers having viscosities in the 50 centipoise range are typical.
Two basic classes of KiON polymers are available. The first type encompasses liquid compositions that can be thermoset (Ceraset® Polyureasilazane or Ceraset Polysilazane 20). These compositions contain sites of ethylenic unsaturation that can be activated to form a crosslinked network through the addition of heat (180-200° C). Commercially available free radical initiators such as dicumyl peroxide are typically used where a thermal cure at a temperature lower than 180-200° C is required. The second type of polymer is tailored to react with various organic resins to form inorganic / organic "hybrid" polymers. This occurs via an addition reaction of the silicon-nitrogen bond in the polysilazane with organic, electrophilic groups in the organic resin (NCO, oxirane, etc…)
Relative to competing polysilazanes, KiON polymers offer:- Lower cost
- Ease of processing
- Room temperature curing
- Excellent shelf stability