Counterion quaternary phosphonium

Effect of Counterion Structure on Ionomer Properties Quaternary Phosphonium Counterions in Sulfonated EPDM... 

A problem in interpreting the effect of different counterions on the mechanical properties of ionic polymers is the difficulty in evaluating how cation-anion interactions are changing from counterion to counterion. For example, metal counterions differ in ionicity as well as in size and valence, and they can have a partially covalent character. In contrast, quaternary phosphonium ions have a number of desirable characteristics that make them particularly attractive as model systems for the study of counterion effects. They have an essentially full positive charge on the heteroatom so partially covalent interactions, fractional charge transfer between the counterion and anion, and hydrogen bonding do not come into play. Furthermore, with quaternary ions there is no possibility of the tautomerism that can occur with nonquatemary ammonium or phosphonium counterions. 

Table III. Comparison of Divalent and Monovalent Quaternary Phosphonium Counterions in a Sulfonated EPDM°...

Sample 16 contains the other divalent quaternary phosphonium counterion in Table III, the tetradecamethylene bistriethylphosphonium... 

The structures of quaternary phosphonium counterions have a major impact on the physical properties of sulfonated EPDM elastomeric iono-... 

Ionic Liquids with different unsymmetrical cations. The most important classes are Ionic Liquids having as cation either imidazolium derivatives or quaternary ammonium ions pyrrolidimium-, piperidimium-, or morpholinium-based derivatives or quaternary phosphonium ions [23]. As counterions, simple halogenides are possible or more hydrophobic ions such as PFg or bis ((trifluoromethyl) sulfonyl) amide (N(S02CF3)2). ... 

Table II presents another group of quaternary tetralkyl phosphonium counterions that were used to neutralize a different batch of sulfonated EPDM. In this table melt-flow as well as tensile data are included. The...

Cationic antistats are generally long-chain alkyl quaternary ammonium, phosphonium, or sulfonium salts with, for example, chloride counterions. They perform best in polar substrates, such as rigid PVC and styrenics, but normally have an adverse effect on the resin s thermal stability. These antistat products are usually not approved for use in food-contact applications. Furthermore, antistatic effects comparable to those obtained from other internal antistats such as ethoxylated amines are only achieved with significantly higher levels, typically, five- to tenfold. 

S.6.2.2. Effect of the Nature of the counterion. Examples of polymerizations that can be carried out with nonmetallic counter-ions (quaternary ammonium, phosphonium ions, etc.) are scarce, the vast majority of them requiring the use of alkali or alkaline-earth cations. 

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