Membrane Transport Behavior and the Lability of Chloride on Polyphosphazenes Bearing Bulky Substituents

Conference · Wed Aug 01 04:00:00 EDT 2007

OSTI ID:915525

Stewart, Frederick F; Klaehn, John R; Orme, Christopher J

Polyphosphazenes are an intriguing class of inorganic polymers where much of their functionality is derived from pendant groups attached to phosphorus. The backbone of the polymer consists of alternating phosphorus and nitrogen atoms where the bonding is conventionally drawn as alternating double and single bonds. Orbital nodes are located at each phosphorus atom resulting in electron delocalization between phosphorus atoms, but not through them. Thus, the polymer backbone has a high degree of flexibility where halogens or other leaving groups can be effectively displaced with nucleophiles. In this paper, the first known example of a polyphosphazene with large quantities of non-labile chloride substituents induced by neighboring group steric effects will be discussed. This example is the result of the substitution of poly[bis-chlorophosphazene] with the sodium salt of 3,5-di-tert-butylphenol where only 60% of the chlorines were displaced. This contrasts with the 100% substitution observed with other phenols (phenol, 4-tert-butylphenol, 3-methylphenol, etc.).

• Research Organization: Idaho National Laboratory (INL)
• Sponsoring Organization: DOE - EE
• DOE Contract Number: AC07-99ID13727
• OSTI ID: 915525
• Report Number(s): INL/CON-07-12459
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMS
BEARINGS
BONDING
CHLORIDES
ELECTRONS
FLEXIBILITY
HALOGENS
INORGANIC POLYMERS
MEMBRANE TRANSPORT
NITROGEN
PHENOL
PHENOLS
PHOSPHORUS
POLYMERS
Polyphosphazene
SODIUM
gas transport
membranes