Fluorosulfonic acids, polymerization

THE can be polymerized by many strongly acidic catalysts, but not all of them produce the requked bitimctional polyether glycol with a minimum of by-products. Several large-scale commercial polymerization processes are based on fluorosulfonic acid, HESO, catalysis, which meets all these requkements. The catalyst is added to THE at low temperatures and an exothermic polymerization occurs readily. The polymerization products are poly(tetramethylene ether) chains with sulfate ester groups (8). 

Fluorosulfonic acid can be used in fluorination reactions, and it functions as a catalyst in reactions such as alkylation and polymerization. One of the most important uses of FS03H and C1S03H is as sulfonating agents to introduce the -S03H group into various organic materials. 

Reaction Scheme I. Polymerization of THE with esters of fluorosulfonic acids... 

Fluorosulfonic acid is a fluorinating agent, and it also functions as an acid catalyst for alkylation, polymerization, and other reactions. Finally, both HSO3F and HSO3CI are... 

It is prepared by passing HF and S03 in fluorosulfonic acid which acts as a solvent as well as heat transfer media. Over 20,000 metric tons of HSO3F are produced per year. It is mostly used as catalyst in the alkylation of branch chain paraffins [26-29], in the polymerization [30-31]. Fluorosulfonic acid is a very strong acid and when added to olefins, it remarkably increases the acidity of the system and enhances its catalytic activity similar to SbF5, TaFs and NbF5 [32-35], It is also used in a chemical process to produce SiF4 [36,37] and BF3 [38],... 

Several strong protonic acids are commercially available. Trifluoro-methanesulfonic (triflic) acid, fluorosulfonic acid, and perchloric acid may be obtained and stored in a pure state. The first two can be conveniently purified by distillation (b.p. 162° C and 165° C, respectively) [12], perchloric acid is less frequently used due to its oxidative properties and difficulties in handling (explosive). Complex acids HPF6 (HF + PF5) and HSbF6 (HF + SbF5) are available as complexes with ethers. Acids of H + BF30H- type are often the real initiators of polymerization initiated with Lewis acids (e.g., BF3) if water is not rigorously excluded from the system. 

Polymerization of THF initiated with fluorosulfonic acid (FSO3H) was studied by H-NMR in A singlet due to the acidic proton, exchangeable during poly-... 

There are various procedures for the preparation of polyethers. These procedures typically start with oxirane or oxirane derivatives (e.g. propylene oxide, etc.). Base catalyzed anionic polymerization, acid initiation, or complex coordination catalysis can be used for the reaction [1-3], Not only oxiranes can generate polyethers. Diols also can be used for polyether synthesis. Other source compounds include tetrahydrofuran, which can be polymerized to a polyether using fluorosulfonic acid (HSO3F) as a catalyst, oxetane (trimethylene oxide) or oxetane derivatives, which can be polymerized to generate polyethers with practical applications such as poly[bis(chloromethyl)oxetane], etc. 

Aliphatic polyamides are extensively studied by natural abundance 15NNMR spectroscopy in solution. However, characterization of polyamides in solution is limited by the insolubility of many (particularly aromatic) polyamides. On the other hand, chemical shifts of amide nitrogens are strongly dependent on the nature of a solvent, and for a particular polyamide, could cover approximately 20 ppm, as in the case of fluorosulfonic acid and trifluoroethanol (see Fig. 2). Since the important properties of solid polyamides such as crystalline structure and hydrogen bonding cannot be studied by solution spectra, the various solid state 15N NMR techniques have been used for structural and dynamical characterization of these polymeric materials. 

Electrochemical homopolymerization of poly(aniline-N-alkylsulfonates) (alkyl = propyl, butyl and pentyl) in acetonitrile containing 0.1 M NaC104 and 5 % (v/v) 0.3 M HCIO4 was carried out by Rhee et al. [144]. The polymers were prepared on a platinum electrode by cyclic voltammetry (0.0 to 1.0 V vs Ag/AgCl) or potentiostatic techniques (1.0 V). These polymers were found to form liquid crystalline solutions in water. The conductivity of poly(aniline-N-propanesulfonic acid) and poly(aniline-N-butanesulfonic acid) was reportly 9 x 10 and 6 x 10 S/cm, respectively. Electrochemical polymerization of orthanilic acid, metanilic acid and sulfonic acid and their copolymerization with aniline in dimethyl sulfoxide containing tetrabutyl ammonium perchlorate were carried out by Sahin et al. [145]. These polymers and copolymers were found to be soluble in water, dimethyl sulfoxide and N-methylpyrrolidinone. The conductivity of orthanilic acid, metanilic acid and sulfonic acid was reportly 0.052,0.087 and 0.009 S/cm, respectively. The conductivity of copolymers for these three isomers of aminobenzene-sulfonic acid was reported as 0.094, 0.26 and 0.033 S/cm, respectively. Sahin et al. [146] have also prepared the copolymers of these three isomers with aniline in acetonitrile containing fluorosulfonic acid (FSO3H). The copolymers were found to be soluble in water, dimethyl sulfoxide and N-methylpyrrolidinone. 

Figure 7.5 Synthesis of hyperbranched glyco-conjugated polymer (Poly6a and Poly6b) by ringopening multibranching polymerization of 1,4-anhydroerythiitol (6a) and 1,4-anhydro-L-threitol (6b) using trifluoromethanesulfonic acid (CF3SO3H) or fluorosulfonic acid (FSO3H).

The protonic initiators that are the most used to polymerize heterocycles are triflu-oromethylsulfonic ( triflic ) and fluorosulfonic acids. 

Strong protonic acids such as trifluoroacetic, fluorosulfonic, and trifluoromethanesulfonic (triflic) acids initiate polymerization via the initial formation of a secondary oxonium ion... 

This type of initiation is limited hy the nucleophilicity of the anion A derived from the acid. For acids other than the very strong acids such as fluorosulfonic and triflic acids, the anion is sufficiently nucleophilic to compete with monomer for either the proton or secondary and tertiary oxonium ions. Only very-low-molecular-weight products are possible. The presence of water can also directly dismpt the polymerization since its nucleophilicity allows it to compete with monomer for the oxonium ions. 

Under certain conditions, irreversible chain-breaking reactions are absent and cationic ROPs of cyclic ethers proceed as living polymerizations. These conditions are found for polymerizations initiated with acylium and l,3-dioxolan-2-ylium salts containing very stable counterions such as AsFg, PFg, and SbClg or with very strong acids (fluorosulfonic and... 

In the polymerization of monocyclic ethers initiated with super adds such as methyl fluorosulfonate and methyl trifluoromethanesulfonate, two kinds of propagating species are observed in the reaction system and an extensive kinetic study has been done for the polymerization of THF, Eq. (6)185). However, the kinetic study of the polymerization of bicyclic ethers with super acid has not been reported. 

A variety of initiator systems of the types used in the cationic polymerization of alkenes (Chapter 8) can be used to generate the tertiary oxonium ion prpoagating species. Strong protonic acids such as sulfuric, trifiuoroacetic, fluorosulfonic, and trifluoromethanesulfonic (triflic) acids initiate polymerization via the initial formation of a secondary oxonium ion ... 

Protonic acids are efficient initiators for the polymerization of both sulfides and amines. The polymerization of thiiranes initiated with perchloric acid proceeds without induction periods. Induction periods are present, however, with methyl fluorosulfonate initiator 11). Secondary sulfonium salts are more reactive than tertiary ones (the opposite is true with oxonium ions)12) and induce rapid polymerization ... 

Iodosyl fluorosulfate, OIOSO2F and the triflate, OIOTf, can be prepared as thermally stable, hygroscopic yellow solids by the reaction of iodine with iodine pentoxide or iodic acid in fluorosulfonic or trifluoromethanesulfonic acids, respectively [5]. Raman and infrared spectra of these compounds indicate a polymeric structure analogous to iodosyl sulfate [5], Iodine tris(fluorosulfate), I(0S02F)3 and tris(triflate), I(OTf)3, are also known [6,26]. I(0S02F)3 can be prepared by the reaction of iodine with peroxydisulfuryl ditluoride [26]. Salts such as KI(0S02F)4 have also been prepared and investigated by Raman spectroscopy [26,27]. I(OTf)3 was prepared from iodine tris(trifluoroacetate) and trifluoromethanesulfonic acid [6]. 

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