Thioether Synthesis for Aerospace Sealants

The patent extracts and eliminates the polythiol component from the synthesis pathway. Instead of using polythiols as starting materials, the invention employs a stepwise synthesis method that builds the polythioether structure from smaller, cheaper molecular building blocks (haloalkanes and thiols), thereby removing the source of high manufacturing costs while preserving the desired fuel resistance properties.

The patent replaces expensive polythiol raw materials with inexpensive small-molecule precursors (haloalkanes and simple thiols). These cheap, readily available starting materials are used in a multi-step synthesis to produce the same functional polythioether product, achieving cost reduction without sacrificing the reliability and fuel resistance of the final sealant composition.

The patent segments the synthesis process into distinct, manageable steps. Rather than relying on complex polythiol chemistry, the invention divides the synthesis into sequential reactions: first forming a halogenated intermediate, then reacting it with thiol groups to build the polythioether chain incrementally. This segmentation simplifies the overall manufacturing process by breaking down complex transformations into simpler, more controllable steps.

The patent introduces intermediate compounds as mediators in the synthesis pathway. The halogenated intermediate serves as a bridge between simple starting materials and the final polythioether product. This intermediary approach allows for better control over the polymerization process, simplifies reaction conditions, and avoids the complexity of direct polythiol-based synthesis while maintaining elevated-temperature resistance.