New Highly Functionalized Primary Allyl, Hydroxyl, and Tosyl Poly(propylene glycol)s (PPG) from Available PPG Derivatization

Abstract

The more stringent reaction conditions used to optimize the synthesis of α,ω-di-O-(4-toluenesulfonyl)poly(propylene glycol) from commercial poly(propylene glycol) (PPG) of 2000 g/mol molar mass, compared to those applied for allowing the same modification on PEG, showed that the secondary hydroxyl end groups were less reactive than the primary ones. Thus, chemical end group transformations were successfully done on this polymer by introducing various groups, such as oxopropyl, carboxymethyl, allyl, 3-hydroxy-n-propyl, and 3-(4-toluenesulfonate)-n-propyl, on its terminal monomer units in order to enhance their reactivity. These reactions were optimized by adjustment of the reaction conditions to obtain fully α,ω-functionalized poly(propylene glycol)s. Particularly, the more reactive primary diallyl, dihydroxyl, and ditosyl poly(propylene glycol)s were obtained with very high functionality within experimental accuracy in a range ±0.1.