Fluorinated aldehyde polymers

FARNHAM AND ZANE Fluorinated Aldehydes and Their Polymers... 

The literature on fluorinated aldehydes and their polymers, although relatively sparse, has been reviewed (5). A reading of this review and the original literature citations reveals that much remains to be learned about this area most of the polymerization studies were carried out with CF3CHO which offers difficult handling problems along with rather intractable polymer. Some mechanistic speculation has been advanced but critical evaluation appears minimal. Longer chain or substituted fluorinated aldehydes have received less attention. 

Chemical Properties. A combination of excellent chemical and mechanical properties at elevated temperatures result in high performance service in the chemical processing industry. Teflon PEA resins have been exposed to a variety of organic and inorganic compounds commonly encountered in chemical service (26). They are not attacked by inorganic acids, bases, halogens, metal salt solutions, organic acids, and anhydrides. Aromatic and ahphatic hydrocarbons, alcohols, aldehydes, ketones, ethers, amines, esters, chlorinated compounds, and other polymer solvents have Httle effect. However, like other perfluorinated polymers,they react with alkah metals and elemental fluorine. 

Torlon-type polymers are unaffected by aliphatic, aromatic, chlorinated and fluorinated hydrocarbons, dilute acids, aldehydes, ketones, ethers and esters. Resistance to alkalis is poor. They have excellent resistance to radiation. If a total of 10 Mrad is absorbed at a radiation dosage of 1 Mrad/h the tensile strength decreases by only 5%. 

The functionalization of polymers is another useful feature of the hydrosilation reaction. The introduction of highly fluorinated alkyl chains by the hydrosilation of Si-H groups of the polymer with fluorinated aUcenes is a typical example. Poly(phenylsilanes) obtained by the dehydrocouphng polymerization of phenylsilane undergo AIBN initiated free radical hydrosilation with aUcenes, ketones and aldehydes. Cross-linking and branching of polymers can also be easily accomplished using hydrosilation. 

NaHCOs, and methanesulfonic anhydride.Dimethyl sulfoxide in 48% HBr oxidizes benzylic alcohols the aryl aldehydes.Note that Swern oxidation of molecules having alcohol moieties, as well as a disulfide, leads to the ketone without oxidation of the sulfur. Sulfoxides other than DMSO can be used in conjunction with oxalyl chloride for the oxidation of alcohols,including fluorinated sulfoxides and a polymer-bound sulfoxide. ... 

The Torlon materials produced by Amoco Chemicals are polyamide-imides of the type shown in Figure 4.20a. Torlon has high strength, stiflEness, and creep resistance, shows good performance at moderately high temperatures, and has excellent resistance to radiation. The polymers are unaffected by all types of hydrocarbons (including chlorinated and fluorinated products), aldehydes, ketones, ethers, esters, and dilute acids, but resistance to alkalis is poor. 

Prakash, Olah, and coworkers developed an efficient strategy using Nafion -H (perfluoroalkanesutfonic acid polymer) and Nafion" SAC-13 (10-20% Nafion -H polymer on amorphous silica, porous nanocomposite) as heterogeneous catalysts for one-pot Strecker reaction using aldehydes, ketones, and fluorinated ketones, affording final a-aminonitriles in high yields [64]. 

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