Furan polymers polyamides

Furan, Furfural, Hydroxymethylfurfural, Furan polymers. Chain polymerizations. Step-growth polymerizations, Furan polyesters, Furan polyamides, Furan polyurethanes, Furan-containing conjugated oligomers, Diels-Alder reaction, Dendrimers, Reversible crosslinking... 

It must be emphasized that the presence of carbonyl groups attached to furan rings represents on the contrary an element of stabilization in furan polymers. Thus, for example, furan polyesters and polyamides are white and do not suffer any stmctural modification over very long periods of time. 

Recent work on the synthesis, structure and some properties of macromolecules bearing furan rings is discussed. Two basic sources of monomers are considered, viz. furfural for monomers apt to undergo chain polymerization and hydroxymethylfurfural for monomers suitable for step polymerization.Within the first context, free radical, catiomc and anionic systems are reviewed and the peculiarities arising from the presence of furan moieties in the monomer and/or the polymer examined in detail. As for the second context, the polymers considered are polyesters, polyethers, polyamides and polyurethanes. Finally, the chemical modification of aU these oligomers, polymers and copolymers is envisaged on the basis of the unique reactivity of the furan heterocycle. 

The most extensive research on furanic polyamides is recent (33) and deals essentially with furanic-aromatic structures, although an important effort was also devoted to all-fiiranic compositions. The reaction of the diacid 11a with various aromatic diamines leads to high-molecular weight polymers with good thermal stability and ciystallinity. Structure 23, obtained with p-phenylenediamine, exhibited features resembling closely those of polyaramides ... 

Functionalization of polymer chains with the chemical groups (furan and maleimide) is a convenient approach to prepare DA-adduct based crosslinked networks. Furan- (PA-F) and maleimide- (PA-Ml) modified polyamides have been prepared for the constmction of crosslinked polyamides (Fig. 12)... 

Chem. Descrip. N-P-(Aminoelhyl)-Y-aminopropylmethyldimethoxysilane CAS 3069-29-2 EINECS/ELINCS 221-336-6 Uses Coupling agent in acrylic, epoxy, polyamide, polyether, silicone, vinyl polymers, cellulosics, furan, melamine, nitrocellulose, PU, polyvinyl butyral, and urea-formaldehyde, for adhesives, coatings, filler Ireat-menL foundry, inks, rubber, sealants, and textile applies. 

Furan derivatives, mainly based on furfural or furfuryl alcohol, have been applied in thermosetting resins for almost a century. In contrast, academic and industrial research into furan based polyesters and polyamides took off in the 1950s. Farly papers (up until the 1970s) are usually rather qualitative, generally just describing the polymer synthesis, combined with rudimentary property analysis. Since the 1980s, more quantitative scientific papers have been... 

Moore, J.A. and Bunting, W.W. (1985) Polyesters and polyamides containing isomeric furan dicarboxylic acids. Polymer Scienceand Technology, Advanced Polymer Synthesis, 31, 51-91. 

A peculiar route to a unique furan polyamide was applied to A-hydroxymethylfuramide prepared in situ from 2-furamide and an excess of formaldehyde, which gave rise to polymer 21 by an acid-catalyzed polycondensation mechanism involving the C5 electrophilic substitution of the heterocycle [4e]. 

A considerable amount of work has been done using furan, J[, derivatives to synthesize polyesters, polyamides, and various other polymeric mater-ials. Much of this work has been completed in the last thirty years, with the majority of it dealing with 2,5-furan dicarboxylic acid and its derivatives. 2,4-Furan dicarboxylic acid, and 3,4-furan dicarboxylic acid, and their derivatives have been less used as starting materials. Little or no polymer synthesis has been reported employing 2,3-furan dicarboxylic... 

Linear, high molecular weight polyamides were obtained when aliphatic, aromatic, and heterocyclic diamines were reacted with aromatic and heterocyclic ortho-dicarboxylic acid dichlorides. Interfacial polymerization of an aqueous, alkaline solution of trans-2,5-dimethyIpiperazine with 3,4-furan dicarbonyl chloride in methylene chloride produced a polyamide in 97% yield with inherent viscosity of 3.71 in H SO. The polymer exhibited good stability to heat and hydrolysis and a glass transition temperature... 

Considering these differences, it is the purpose of this work to synthesize representative polyesters and polyamides which incorporate derivatives of the four isomeric furan dicarboxylic acids, and to determine if these polymers bear any relationship in properties to similar polymers derived from benzene. Similarity in basic position and distance between carboxyl groups may permit examination and ordering of poljnners containing the isomeric benzene diacids. Some comparisons are shown below. 

Interfacial and solution polymerization techniques were used to prepare the polymers. Each of the isomeric furan diacids was pol5nnerized with 2,2-bis(4-hydroxyphenyl)propane (BPA), 4,4 -thiodiphenol (TDP), and 4,4 -sulfonyl diphenol (BPS), to prepare the corresponding polyesters, and with 2,2-bis(4-aminocyclohexyl)propane (BACP) and bis(4-aminocyclohexyl) methane (BACM) to make the polyamides. 

For completeness, after discussing the histories of carbon fibers derived from cellulose, PAN, and pitch, the category of "other precursors" should be covered. The tremendous activity in carbon fiber research and development is reflected in the large number of precursors which have been converted into carbon fibers. Besides the "big three", the list [34] includes phenolic polymers, phenol formaldehyde resin, furan resins [35], polyacenaphthalene, polyacrylether, polyamide, polyphenylene, polyacetylene, polyimide, polybenzimidazole, polybenzimidazonium salt, polytriazoles, modified... 

As initial synthetic targets, polyester and polyamide (Fig. 16) were chosen, as representatives of a series of tetrahydro-furan-containing polymers, because of their structural simplicity... 

---