Use of telechelic fluorinated diiodides to obtain well-defined fluoropolymers

https://doi.org/10.1016/S0022-1139(99)00220-1Get rights and content

Abstract

Different methods of synthesis involved in the preparation of fluorinated telechelics (or α,ω-difunctional compounds) from α,ω-diiodoperfluoroalkanes for obtaining well-defined fluoropolymers are described. This review focuses on molecules in which fluorinated chains are located on the backbone and not in a lateral position. First, a bibliographical approach develops the syntheses of α,ω-diiodoperfluoroalkanes (1) either by chemical transformations of telechelic derivatives or by telomerisation of fluoroolefins with molecular iodine or diiodoperfluoroalkanes. Then, fluorotelechelics are synthesised by means of four different processes: (a) by the chemical change in the presence of metalic salts; (b) from the bismonoaddition of 1 to ω-functional unsaturated derivatives; (c) from the bis(monoethylenation) of 1 followed by difunctionalisation (e.g., nucleophilic substitution); (d) from the coupling reactions between 1 and α-iodo-ω-functional reactants. Finally, this review describes how several well-defined fluoropolymers can be produced from these fluorinated telechelics. Their specific chemical, physical and thermal properties are discussed with regard to modern industrial requirements.

Introduction

Fluorinated polymers exhibit a unique combination of high thermal stability, chemical inertness (to acids, bases, solvents and petroleum), low dielectric constants and dissipation factors, low water absorptivities, excellent weatherability and a good resistance to oxidation and ageing, low flammabilities and very interesting surface properties [1], [2], [3].

Therefore, such products are involved in many applications (aerospace, aeronautics, engineering, optics, textile finishing, microelectronics) in spite of their high price but are undergoing an increasing market.

Well-architectured polymers can be prepared either from controlled radical polymerisation [4], [5] or from polycondensation or polyaddition. In these two last processes, telechelic or α,ω-difunctional (i.e., the functional groups are located at both extremities of the chain) precursors are required to obtain high molecular weight materials with satisfactory properties [6]. In the case of fluorinated telechelics, the literature describing their synthesis is abundant and it was reviewed several years ago [7], [8].

Two kinds of fluorinated telechelics exhibiting different properties are suggested and hence the polymers prepared from them can be involved in different applications. On the one hand, those possessing the fluorinated group in a lateral position about the polymeric backbone are searched for their enhanced surface properties but can not be used as thermostable materials resistant to oxidation and to chemicals. On the other hand, those containing the fluorinated chain in the backbone exhibit much better thermal properties and are also resistant to aggressive media, to UV radiations and to ageing.

Various strategies have been proposed to prepare this second family of fluorinated telechelics. In 1969, Rice and Sandberg [9] used the dead end copolymerization of vinylidene fluoride and hexafluoropropene in the presence of telechelic peresters. More recently, such a process was successfully achieved from hydrogen peroxide [10].

Nowadays, among fluorinated telechelics prepared on an industrial scale only three commercially available polyethers have already been obtained as follows:

  • 1.

    the anionic polymerisation of perfluoroepoxides (especially hexafluoropropylene oxide) led to Krytox® produced from Du Pont de Nemours Company [11], [12] as follows;

  • 2.

    the photooxidation of perfluoroolefins (e.g., tetrafluoroethylene [13], hexafluoropropene (HFP) [14] and perfluorobutadiene [15]) was performed by the Ausimont Company yielding functional or nonfunctional Fomblin® oligomers ranging from 1000 to 2000 in molecular weights [16] (where

    represents a function;

  • 3.

    the Daikin Company commercialises Demnum® oligomers, which can be inert or functional, from the ring opening polymerisation of fluorinated oxetanes followed by a fluorination to obtain thermostable oils [17].

A part from fluorinated polyethers, original fluorotelechelic oligodiols as random copolymers containing vinylidene fluoride (VDF) and HFP base units, e.g. HOCH2CF2(CH2CF2)p[CF(CF3)CF2]qCF2CH2OH have been synthesised by Chan et al. [18].

In addition, the synthesis of telechelic fluorinated diols from direct fluorination [19] of hydrogenated diols, produced in pilot plants, has successfully been achieved [20].

In spite of the lack of industrial fluorotelechelics (different from polyethers) about fluorinated nonfunctional homo and copolymers, the nowadays tendency shows that a growing interest is still required, as evidenced by numerous investigations [7], [8]. It seems that many reactions involve α,ω-diiodoperfluoroalkanes as reactants, to prepare telechelic intermediates preserving the fluorinated chain in the backbone.

Hence, it was worth summarising the usefulness of these diiodides as precursors of well-defined fluoropolymers. The objective of that review is to reshuffle surveys in this field of research. It is composed of three parts, each of them being dependent of both others in the chain of the preparation of these special fluoropolymers. The first one describes the various routes leading to α,ω-diiodofluoroalkanes while the second one overviews the syntheses of fluorotelechelics from them. Then, how can one use these original telechelics to prepare well-defined polymers? This last part also details the properties and applications of these latters.

Section snippets

Synthesis of α,ω-diiodo(per)fluoroalkanes

Although perfluoroalkyl iodides are widely used as reactants for the synthesis of fluorinated derivatives [21], [22], this is not the case for α,ω-diiodoperfluoroalkanes, because of the difficulty of synthesis, and their corresponding price.

However, a large variety of preparations of α,ω-diiodoperfluoroalkanes has been investigated and can be gathered in two different ways: from organic synthesis (mainly by chemical change of fluorotelechelics) and from telomerisation reactions of fluoroolefins

Functionalisation of α,ω-diiodo(per)fluoroalkanes for the obtaining of fluorinated telechelics

Several ways are possible to enable the diiodides to be functionalized. Basically, these routes can be gathered into four families:

  • 1.

    Direct transformation of both iodine atoms into functions, as follows (Met designates a metal):IRFI+2MetRF+2MetI

  • 2.

    Functionalisation from the bis(monoaddition) of the diiodides to ω-functional-α-ethylenic derivatives (

    and R designate a functional and a spacer groups, respectively):IRFI+2H2CCHRRCHICH2RFCH2CHIR55+H2orHRC2H4RFC2H4R5

    The first

Synthesis of well-architectured fluoropolymers from fluorinated telechelics

Telechelic diols, diacids, diisocyanates, diamines, dienes are among the most promising starting materials for the synthesis of well-architectured fluoropolymers via condensation polymerisations or polyaddition polymerisations.

Several examples of preparation of such various fluoropolymers are presented in the following sections.

Conclusion and perspectives

Although perfluoroalkyl iodides are quite versatile compounds involved in many investigations to introduce a perfluorinated group on a molecule thanks to its low CF2–I bond dissociation energy, α,ω-diiodofluoroalkanes have not got same fate since less researches have been performed from them. This is mainly due to their difficult synthesis and their price. However, it can be assumed that these drawbacks may be overcome by the improvement of the synthesis which should make them readily

References (188)

  • P. Tarrant

    J. Fluorine Chem.

    (1984)
  • B. Boutevin et al.

    Tetrahedron Lett.

    (1973)
  • M.O. Riley et al.

    J. Fluorine Chem.

    (1977)
  • H. Fukaya et al.

    J. Fluorine Chem.

    (1997)
  • J.A. Renn et al.

    J. Fluorine Chem.

    (1997)
  • V. Tortelli et al.

    J. Fluorine Chem.

    (1990)
  • S.V. Kotov et al.

    J. Fluorine Chem.

    (1988)
  • B. Améduri et al.

    J. Fluorine Chem.

    (1995)
  • B. Améduri et al.

    J. Fluorine Chem.

    (1999)
  • D.S. Ashton et al.

    J. Chromatography

    (1974)
  • A. Manséri et al.

    J. Fluorine Chem.

    (1995)
  • J. Balagué et al.

    J. Fluorine Chem.

    (1995)
  • A. Manséri et al.

    J. Fluorine Chem.

    (1996)
  • J. Balagué et al.

    J. Fluorine Chem.

    (1995)
  • D. Boulahia et al.

    J. Fluorine Chem.

    (1999)
  • V. Cirkva et al.

    J. Fluorine Chem.

    (1995)
  • A.E. Mera et al.

    J. Fluorine Chem.

    (1994)
  • T. Takakura et al.

    J. Fluorine Chem.

    (1988)
  • S. Nadji et al.

    J. Fluorine Chem.

    (1991)
  • B.E. Smart, Properties of fluorinated compounds, physical and physicochemical properties, in: M. Hudlicky, S.E. Pavlath...
  • J. Scheirs, Modern Fluoropolymers, Wiley, New York,...
  • G. Hougham, K. Johns, P.E. Cassidy, Fluoropolymers: Synthesis and Properties, Plenum Press, New York,...
  • K. Matyjaszewski, Controlled Radical Polymerization, ACS Symp. Series 685, American Chemical Society, Washington, DC,...
  • M. Oka et al.

    Contemp. Topics Polym. Sci.

    (1984)
  • E.J. Goetals, Telechelic Polymers and their Applications, CRC Press, Boca Raton, FL,...
  • B. Boutevin et al.

    Advances Polym. Sci.

    (1992)
  • B. Améduri et al.

    Advances Polym. Sci.

    (1992)
  • D.E. Rice, US Patent 3461155 (to 3M) (1969); R.E. Rice, C.K. Sandberg, Polym. Preprint. Amer. Chem. Soc. Div. Polym....
  • R. Saint-Loup, A. Manséri, B. Améduri, B. Boutevin, B. Lebret, P. Vignane, Presented at the 4th French Conference in...
  • E.P. Moore, US Patent 3322826 (to DuPont de Nemours),...
  • H.S. Eleuterio

    J. Macromol. Sci. Chem.

    (1972)
  • G. Caporiccio, G. Viola, C. Corti, Eur. Patent 89820 (to Montedison),...
  • D. Tanesi, A. Pasetti, C. Corti, US Patent 3442942 (to Montedison),...
  • D. Sianesi, A. Pasetti, G. Belardinelu, US Patent, 4451646 (to Montefluos),...
  • G. Caporiccio

    J. Fluorine Chem.

    (1986)
  • O. Yohnosuke, T. Takashi, T. Shogi, Eur. Patent Appl. 0148482 (to Daikin 26-12-1983) [Chem. Abstr. 104 (1986)...
  • M.L. Chan, R. Reed Jr., H.G. Gollmar, C. Gotzmer, R.C. Gill, US Patent 5049213 (to US Navy...
  • R.J. Lagow, H.C. Wei, Direct fluorination of polymers, in: G. Hougham, K. Johns, P.E. Cassidy (Eds.), Fluoropolymers:...
  • H. Kawa, Synthesis of unique fluorinated diols, Proceedings of Fluorine in Coatings III Conference, Orlando, FL, 25–27...
  • R.N. Haszeldine

    J. Fluorine Chem.

    (1986)
  • W. Mahler

    Inorg. Chem.

    (1963)
  • R.A. Mitsch

    J. Heterocycl. Chem.

    (1964)
  • H.S. Kesling, D.J. Burton, Tetrahedron Lett. 3358 (1975); G.A. Wheaton, D.J. Burton, J. Org. Chem. 43 (1978)...
  • Q.Y. Chen et al.

    Sci. Sinica, Ser. B

    (1987)
  • S. Elsheimer et al.

    J. Org. Chem.

    (1984)
  • R.E. McArthur, J.H. Simons, in: L.F. Audrieth (Ed.), Inorganic Synthesis, vol. 3, McGraw-Hill, New York, 1950, p....
  • H. Soroos et al.

    J. Am. Chem. Soc.

    (1945)
  • D.B. Su, J.X. Duan, Q.Y. Chen, J. Chem. Soc. Chem. Comm. (1992)...
  • A.R. Li, Q.Y. Chen, Synthesis (1997) 1481; J. Fluorine Chem. 82 (1997)...
  • B.E. Smart, Private...
  • Cited by (53)

    • A Critical Assessment of the Kinetics and Mechanism of Initiation of Radical Polymerization with Commercially Available Dialkyldiazene Initiators

      2019, Progress in Polymer Science
      Citation Excerpt :

      ITP involves conducting a polymerization with a conventional initiator (often a dialkyldiazene) in the presence of an activated alkyl iodide (R–X in Scheme 17). In a RDRP context, the method was originally applied to mediate polymerization of styrene [367–369], acrylates [367], VAc [370,371] and various fluoro-olefins [372,373]. The mechanism for ITP involves degenerative chain-transfer as shown in Scheme 17 with X = iodine.

    • 3.06 - Degenerative Transfer with Alkyl Iodide

      2012, Polymer Science: a Comprehensive Reference: Volume 1-10
    • Telechelic polymers by living and controlled/living polymerization methods

      2011, Progress in Polymer Science (Oxford)
      Citation Excerpt :

      These are (i) direct functionalization, (ii) functionalization by substitution after ethylenation and (iii) radical coupling (Scheme 37) [696]. Telechelic fluoropolymers having diol, diacid, diisocyanate, diamine, diene functionalities are very promising starting materials for the production of commercial polymers via condensation polymerizations or polyaddition polymerizations [697]. Although, cobalt mediated radical polymerization is the first example of C/LRP [686–688], the method had not been established well, because it is limited to only acrylates.

    View all citing articles on Scopus
    View full text