Organic polymers are based on carbon atoms linked together in chains of varying length and structure. These materials are widely used, but their use is largely limited to low temperature applications. A great deal of effort has been expended in attempts to enhance their thermal resistance. However, these organic materials still tend to degrade, and ultimately be destroyed, at relatively low temperatures.
For higher temperature use, interest has centered in glasses and ceramics, or in inorganic polymers. Glasses and ceramics can be tailored to meet most high temperature applications. However, these materials require high melting, or sintering, temperatures, thus rendering them expensive to produce.
Known inorganic polymers are primarily based on silicon, and are referred to as silicones. These materials have been developed over the past half century, and are widely employed in intermediate temperature applications. They do not, however, provide the high temperature service available with glasses and ceramics.
The present invention provides a family of polymeric materials based on phosphorous. These polymers are basically inorganic in nature, but also have an associated organic group. They are of particular interest because they can be formed at room temperature, and then thermally converted to a glass or crystalline state. However, the conversion is at a temperature well below that normally required to melt a glass. Further, the phosphorous polymers may have additives that provide a wide range of glasses or crystalline phases.
USPTO Backgrounds
USPTO Backgrounds