Robust and Operationally Simple Synthesis of Poly(bis(2,2,2-trifluoroethoxy) phosphazene) with Controlled Molecular Weight, Low PDI, and High Conversion

Abstract

Synthetically straightforward conditions have been developed for the preparation of poly(bis 2,2,2-trifluoroethoxy)phosphazene with low PDI (<1.15) at high conversion (75−99%) and on a multigram scale. A combination of 31 P NMR and GPC analyses demonstrate that molecular weight increases linearly as a function of monomer consumption, exhibiting first order kinetics with respect to monomer concentration up to high monomer conversion. Thus, the molecular weight can be controlled by varying the initiator (H 2 O) to monomer ratio.

Main-Chain Phosphorus-Containing Polymers for Therapeutic Applications

“…Controlled polymerization of the relatively accessible monomer trifluoroethoxyphosphoranimine is also possible, resulting in polymers with narrow Ð values of approximately 1.15 for an M n of 25 KDa (Figure 4) [24]. It is thought that rapid initiation by traces of H 2 O produces a phosphazene anion that propagates monodirectional growth at the TMS (trimethylslilyl) end of the polymer.…”

A strategy for the synthesis of cyclomatrix-polyphosphazene nanoparticles from non-aromatic monomers

“…A small quantity of reaction solutions was removed and placed in NMR tubes, which contained a sealed capillary tube with benzene-d 6 . 31…”

“…We used 31 P NMR with PPZ-CysM as an example to illustrate qualitatively the substitution rate of CysM on HCCP. 31 oligomers, when their molar feed ratio is higher than 1 : 5 or higher than 1 : 4, respectively, it is failed to trigger the formation of any precipitation by water. This is because the higher hydrophilicity makes the oligomer soluble in water, then we name Phase IV water non-triggerable oligomer area.…”

“…On one hand, the "living" cationic polymerization method was developed to achieve polyphosphazene with narrow molecular weight distribution and complex architectures. [28][29][30][31] On the other hand, a new alternative class of polyphosphazenes, i.e., cyclomatrix polyphosphazenes (C-PPZs), has emerged in the last decade as nanomaterials. 32 C-PPZs can be obtained easily and in large quantities by precipitation polycondensation from HCCP and organic monomers or polymers (diols/di-amines) as nanoparticles under ambient conditions.…”

Controlled Synthesis of Polyphosphazenes with Chain-Capping Agents

“…Polyphosphazene random and block copolymers with mixed alkoxy/alkoxyether substituents were subsequently prepared by the fluoride/anionic method and characterized [ 37 ]. Other examples include polyphosphazenes with alkyl or aryl substituents [ 38 ], polyphosphazenes with electronegative nitropropoxy groups bound to the phosphorus atom of the N -silylated phosphoranimine [ 39 ], polymerization of N -silyl- P -diethyl phosphoranimine with fluoride and phenoxide initiators [ 40 ], and P -tris(trifluoroethoxy)- N -trimethylsilyl phosphoranimine polymerized with water in the presence of N -methylimidazole initiator in diglyme solution polymerization [ 41 ].…”