Functionalization of Soluble Guayule Resins using Functional Dithiophosphoric Acids

Functionalized polymers of a reaction product of a polymer including one or more olefins and a dithiophosphoric acid compound can provide a wide range of olefinic polymers in bulk-neat conditions or in solution via eletrophilic addition processes. Such new compositions provide a wide range of new functional polymers via an inexpensive polymer production process and as a route to low cost, specialty optical and flame retardant polymers. Suitable olefins include polybutadienes, polyisoprenes, natural soluble or gum rubber, guayule resins, polydienes, and cyclic olefins.  

Background:
Dithiophosphoric acids (DTPAs) can be readily made by the reaction of phosphorus pentasulfide (P2S5), or the dimeric form (P4S10) with alcohols (ROH) to form a mono-functional dithiophosphoric acid. While dithiophosphoric acids have long been known in organic synthesis, the application and utility of these molecules for polymer functionalization have not been developed.

Applications:

• Production of natural rubber, soluble polydienes, synthetic SBR
• Polynorbornene derivatives and other polymers derived from ring-opening metathesis
• Any polymer containing an unsaturation
• Optical polymers with high refractive index
• Flame retardant polymers

Advantages:

• Low cost raw materials
• Neat/bulk or solution processing
• New composition space for tuneability