Poly imide synthesis

Water offers environmental and eeonomie benefits. However, there emerges one disadvantage of this method, as the proeess is complete in one step. The aqueous poly(imide) synthesis route results in products that... 

Water offers environmental and economic benefits. However, there emerges one disadvantage of this method, as the process is complete in one step. The aqueous poly(imide) synthesis route results in products that are not processable, if the resulting PI is insoluble and infusible [35]. Alternatively, fluorinated monomers can be used to get processable and high-temperature stable products. Or else, low-molecular-weight intermediate thermoset products could be produced. 

Bolger JC. Polyimide die attach adhesives for LSI ceramic packages. In Mittal KL, ed. Poly-imides Synthesis, Characterization, and Applications, Vol 2. New York, NY Plenum Press 1984 871-887. 

These syntheses can be considered as heterocyclic analogue of the poly(ether imide) synthesis... 

Polyamide-6 (PA-6), synthesis of, 174-176. See also PA-6 entries Polyamide endgroups, 161 Poly amide-imide, synthesis of, 291 Polyamides (PAs), 135-193. See also Nylons PA entries acid chloride polymerization of, 155-157... 

McGrath, /. E, Dunson, A L., Hedrick,l L.i Synthesis and Characterization of Segmented Poly-imide-Polyorganosiloxane Copolymers. Vol. 140, pp. 61-106. 

Shobha et al. employed a novel sulfonated diamine containing a phosphine oxide moiety in the synthesis of a five—membered ring sulfonated poly-imide. The synthesis is shown in Figure 24. 

Postsulfonation of polymers to form PEMs can lead to undesirable side reactions and may be hard to control on a repeatable basis. Synthesis of sulfonated macromolecules for use in PEMs by the direct reaction of sulfonated comonomers has gained attention as a rigorous method of controlling the chemical structure, acid content, and even molecular weight of these materials. While more challenging synthetically than postsulfonation, the control of the chemical nature of the polymer afforded by direct copolymerization of sulfonated monomers and the repeatability of the reactions allows researchers to gain a more systematic understanding of these materials properties. Sulfonated poly(arylene ether)s, sulfonated poly-(imide)s, and sulfonated poly(styrene) derivatives have been the most prevalent of the directly copolymerized materials. 

A novel cure chemistry employed for addition poly(imides) has recently been published. The successful preparation of 4-aminobenzocyclobutene allowed the synthesis of benzocyclobutene-terminated imide oligomers and bisfbenzocylobutenes) (17). The benzocyclobutene group is a latent diene which isomerizes to o-guinodimethane at temperatures of about 200 °C and may homo- and/or co-polymerize for example with bismaleimide (83). Details on the benzocyclobutene chemistry are described in chapter I of this book. 

A great deal of literature attention has been devoted to polymers in this section as thermally stable polymers (B-80MI11101). While some very elegant syntheses have been conducted, the resulting polymers have been, for the most part, quite intractable materials not conducive to extensive screening for a variety of applications. Thus, aside from their bulk thermal performance, little else besides the conditions of synthesis is known about most of the polymers shown. Three notable exceptions about which considerable characterization and product information are available are poly(imides), poly(benzimidazoles) and poly(quinoxalines), and a short discussion is included concerning properties and applications of these polymers. 

Johnson BC, Yilgor I, McGrath JE (1984) Synthesis of poly(imide)-polysiloxane segmented copolymers. Polymer Preprints 25(2) 54... 

Bott RH, Summers JD, Arnold CA, Taylor LT,Ward TC, McGrath JE (1987) Synthesis and characteristics of novel poly(imide siloxane) segmented copolymers. J Adhes 23(2) 67... 

Moyer ES, Mohanty DK, Shaw J and McGrath JE (1989) Synthesis and characterization of soluble photoimageable polyimide and poly(imide siloxane) homo- and copolymers. 3rd International SAMPE Electronics Conference, p 894... 

Coordination carbonylation polycondensation has been extended from the synthesis of polyamides [scheme (15)] and polyarylates [scheme (16)] to reactions using other nucleophilic monomers that, with dihaloarenes and carbon monoxide, yield poly(imide-amide)s, poly(acylhydrazide)s, and poly(benzoxa-zole)s [165,170,171],... 

The synthesis and properties of poly(imide-siloxane) polymers and copolymers based on 5,5 bis(lyly3,3-tetramethyl-l,3-disiloxane-diyl)norbornane dicarboxylic anhydride are described. High-molec-ular-weight thermoplastics and elastoplastics were prepared readily in solution from aromatic diamines, organic dianhydrides, and this unique anhydride-terminated siloxane. The thermal and mechanical properties of a variety of copolymer compositions are described. Average siloxane block length and overall siloxane content had the greatest effect on these properties. 

The traditional approach used in poly(imide-siloxane) synthesis is the reaction of aminopropyl-terminated dimethylsiloxane oligomers with aromatic dianhydrides and additional diamines (9-13). Typically, subambient temperatures and dipolar aprotic solvents are used. The resulting high-molecular-weight polyamic acid solution can be heated to effect imidization and solvent evaporation. This procedure is analogous to the synthetic method used to prepare conventional polyimides for films and coatings. 

Poly(imide)s first became commercially important with the development of the condensation poly(imide) Kapton [4, 5] in 1965. The two-step reaction of a dianhydride (pyromellitic dianhydride) with a diamine (p-phenylene diamine) to initially form a poly(amic acid), and subsequent thermal cycliz-ation to form the poly(imide), is a common route to the formation of poly-(imide)s, as well as being exploited for the synthesis of oligomeric precursors for addition poly(imide)s. Usually, such condensation polymers are insoluble... 

Work on improving the thermal resistance and particularly the resistance to carbonization (short circuiting of layers of enameled wires under the influence of temperature) via special glycols led to diphenols [29,30]. Diphenols are not reactive under the conditions of a normal poly(ester-imide) synthesis. In synthesis the lower aliphatic diesters of diphenols were used [29-32]. The use of acid chlorides in the polyester reaction with aromatic OH-groups was also protected by patents [33-35] but it seems unlikely that this reaction was performed on the production scale. 

Kricheldorf has reported the synthesis of lyotropic poly(amide-imide)s and poly(benzoxazole-amide)s. These were prepared by the polycondensation of N,N-bis(trimethylsilyl)-p-phenylenediamine or N,AT -bis(trimethylsilyl)-3,3 -dim-ethylbenzidine with the diacyl chloride of trimellitimide of p-aminobenzoic acid, or the imide formed from p-amino benzoic acid and terephthalic acid. Lyotropic behaviour was observed in cone, sulphuric acid solution [38]. A series of thermotropic poly(imide-amide)s was prepared based on trimellitimides formed from trimellitic anhydride and an a, -bis(4-aminophenoxy) alkane with carbon chain lengths 9-12. Melting points were in the range 250-300 °C. They formed smectic A phases and tended to degrade around the isotropisation temperatures (around 350 °C). Pendant methyl groups or occupied meta- groups tended to prevent mesophase formation [39]. Novel LC poly(imide-amides) have also been synthesised from new diamine spacers derived from linear diaminoalkanes and 4-nitrophthalic anhydride. A smectic and nematic phase were observed when 4,4 -biphenyl dicarboxylic acid was used as co-monomer [40]. 

Classification by Decomposition Behavior. The decomposition mechanism is a reasonable way to classify polymers. They can either depolymerize upon irradiation, for example, poly(methylmethacrylate), or decompose into fragments such as poly-imides or polycarbonates. This method of classification is closely related to the synthesis of polymers. Polymers that are produced by radical polymerization from monomers, which contain double bonds, are likely to depolymerize into monomers, while polymers that have been formed by reactions like polycondensation will not depolymerize into monomers upon irradiation, but will be decomposed into different fragments. The second group cannot be used to produce films with the same structure or molecular weight as the original material with methods such as PLD. 

Through the synthesis of poly(urethane-imide) films and their carbonization, carbon films were obtained whose macropore structure could be controlled by changing the molecular structure of polyurethane prepolymer [164-166]. Poly(urethane-imide) films were prepared by blending poly(amide acid), which was synthesized from pyromellitic dianhydride (PMDA) and 4,4 -oxydianiline (ODA), and phenol-terminated polyurethane pjrejwlymers, which were synthesized through the reaction of polyester polyol with either hexamethylene diisocyanate (HDI), tolylene-2,4-diisocyanate (TDI) or 4,4 -diphenyknethane-diisocyanate (MDI). The reaction schemes of two components, poly(imide) (PI) and poly(urethane) (PU), are shown in Fig. 46a). 

Sulfonated monomers were also used for the synthesis of sulfonated poly-imides [123,124]. hi particular, sodium salt of the sulfonated bis-4-[(3-aminophenoxy)phenyl]phenylphosphine oxide was used for the preparation of sulfonated polyimides [123]. 

Ghosh A, Sen SK, DasguptaB, Banerjee S, Voit B. Synthesis, characterization and gas transport properties of new poly(imide siloxane) copolymers from 4,4 -(4,4 -isopropylidenedi-phenoxy)bis(phthalic anhydride). J Membr Sci2010 364(l-2) 211-8. 

Toiserkani H. Organosoluble and thermally stable of benzazole-contaiiung poly(imide-urea)s one-pot synthesis and characterization. Open J Polym Chem 2011 01(01) l-9. 

Pei X, Chen G, Fang X. Synthesis and properties of poly(imide siloxane) block copolymers with different block lengths. J Appl Polym Sci 2013 129(6) 3718-27. 

Ghosh A, Banerjee S, Voit B. Synthesis and characterization of fluorinated poly (imide siloxane) copolymers containing anthracene moieties in the main chain. High Perform Polym 2010 22(1) 28 1. 

Govindaraj B, Sarojadevi M. Synthesis and characterization of poly (imide-benzimidazole) hybrid nanocomposites using nano-cluster of octa-amino functionalized polyhedral oligomeric silsesquioxane. Polym Compos 2013 34(6) 825-33. 

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