Abstract:
A multi-stage process for forming a liquid crystalline polymer is provided. More particularly, the process includes acetylating one or more precursor monomers and melt-polymerizing the acetylated monomers to form a prepolymer in the form of a solid particulate material. Thereafter, the prepolymer is solid-state polymerized in a fluidized bed reactor that contains a porous surface (e.g., bed, plate, grate, etc.) on which the prepolymer is supported. While supported by this porous surface, the prepolymer can become “fluidized” with a heated stream of a gas (e.g., nitrogen). In this manner, a sufficient degree of turbulence is created to distribute heat evenly around the prepolymer and cause it to rapidly reach the target reaction temperature.
Abstract:
A polymer composition that contains a polyaryletherketone and thermotropic liquid crystalline polymer, which are melt processed in the presence of a flow modifier. The flow modifier is a functional compound that contains one or more hydroxyl functional groups.
Abstract:
Polymer compositions are described that are well suited for producing reflectors for light-emitting devices, such as light-emitting diodes. In one embodiment, the polymer composition contains a polymer resin and a stabilizer comprising a phosphonate compound and/or a phosphate compound and optionally a white pigment. The polymer resin may comprise, for instance, a poly(1,4-cyclohexanedimethanol terephthalate). The phosphate stabilizer has been found to significantly improve the stability of the polymer composition without interfering with the ability of the composition to bond to other polymer materials, such as silicone resins. Silicone resins, for instance, are typically used as an encapsulant for light-emitting diode assemblies.
Abstract:
A multi-stage process for forming a liquid crystalline polymer is provided. More particularly, the process includes acetylating one or more precursor monomers and melt-polymerizing the acetylated monomers to form a prepolymer in the form of a solid particulate material. Thereafter, the prepolymer is solid-state polymerized in a fluidized bed reactor that contains a porous surface (e.g., bed, plate, grate, etc.) on which the prepolymer is supported. While supported by this porous surface, the prepolymer can become “fluidized” with a heated stream of a gas (e.g., nitrogen). In this manner, a sufficient degree of turbulence is created to distribute heat evenly around the prepolymer and cause it to rapidly reach the target reaction temperature.