A Survey of Some Recent Advances in Step-Growth Polymerization

Chapter 18

A Survey of Some Recent Advances in StepGrowth Polymerization 1

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Downloaded by STANFORD UNIV GREEN LIBR on October 14, 2012 | http://pubs.acs.org Publication Date: May 5, 1996 | doi: 10.1021/bk-1996-0624.ch018

Jeff W. Labadie , James L. Hedrick , and Mitsuru Ueda

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1

Argonaut Technologies, Inc., 887 Industrial Road, San Carlos, CA 94070 Research Division, IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120-6099 Department of Materials Science and Engineering, Yamegata University, 4-3-16 Jonan, Yonezawa, Yamagata 992, Japan 2

3

The field of step-growth polymers encompasses many polymer structures and polymerization reaction types. This chapter attempts to cover topics in step-growth polymerization outside of the areas reviewed in the other introductory chapters in this book, i.e., poly(aryl ethers), dendritic polymers, high-temperature polymers and transition-metal catalyzed polymerizations. Polyamides, polyesters, polycarbonates, poly(phenylene sulfides) and other important polymer systems are addressed. The chapter is not a comprehensive review but rather an overview of some of the more interesting recent research results reported for these step-growth polymers, including new polymerization chemistries and mechanistic studies. Aromatic Polyamides Aromatic polyamides (aramids) are important in the commercial fibers industry because of their high tensile strength and good flame resistance. The demand for these materials is increasing as new applications are found. One example is their use in composites where high-use temperatures, light weight, chemical resistance, and dimensional stability are crucial. The most widely employed synthetic route to aramids is based on the polycondensation of dicarboxylic acids with diamines in the presence of condensing agents. Good reviews on the synthesis of aramids have recently appeared (1-3). Recently, promising alternative synthetic routes to aramids have been reported and are described herein. These include the polycondensation of N-silylated diamines with diacid chlorides, the addition-elimination reaction of dicarboxylic acids with diisocyanates, and the palladium-catalyzed carbonylation polymerization of aromatic dibromides, aromatic diamines and carbon monoxide. The synthesis of aramids from N-silylated amines has been employed because N-silylated aromatic amines show higher reactivity relative to the parent diamines and the resulting trialkylsilyl halide does not lower the reactivity of unreacted amine functionality as is the case with amine protonation 0097-6156/96/0624-0294$12.00/0 © 1996 American Chemical Society In Step-Growth Polymers for High-Performance Materials; Hedrick, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1996.


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Recent Advances in Step-Growth Polymerization

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when HC1 is released (4). This method has been successfully applied in the preparation of fluorine-containing aramids which were unobtainable by a conventional method (5). Polycondensation of tetrafluoro-m-phenylene diamine with aromatic diacid chlorides gave low molecular weight polymers because of the poor nucleophilicity of the fluoro-diamine. However, polycondensations carried out with N-silylated tetrafluoro-m-phenylene diamine with aromatic diacid chlorides in N M P at 0 ° C afforded polymers with inherent viscosities up to 0.47 d L / g . This method has also been applied to the synthesis of N-phenylated aramids of high molecular weights from N,N'-bis(trimethylsilyl)-p-dianilinobenzene and aromatic diacid chlorides (6). Isocyanates have been shown to undergo a high yield reaction with carboxylic acids to afford amides. Polymerization of aromatic diisocyanates with aromatic dicarboxylic acids was carried out in the presence of 3-methyl-l-phenyl-2-phospholene 2-oxide to afford aramids (7). The polymerization was carried out in sulfolane at 200 °C. Polymers with inherent viscosities of up to 1.8 d L / g were obtained. Ring-opening polymerization of aromatic cyclic oligomers has been an area of great interest since they can offer unique advantages in the manufac ture of important products such as molding and composite resins. The syn thesis of aramids by ring-opening polymerization of macrocyclic oligoamides has been reported employing this approach (8). Polymerization occurred at 300 °C in the presence of l-methyl-3-n-butylimidazole-2-thione and phenylphophinic acid as the condensing agent. Polymers with inherent viscosities as high as 0.82 d L / g were obtained. Transition-metal catalyzed polymerizations are an attractive method for the synthesis of condensation polymers, many of which are inaccessible by other methods. The palladium-catalyzed reaction of aromatic bromides, amines and carbon monoxide yields aromatic amides in high yields (9). Imai extended this chemistry to polymer synthesis through the use of bifunctional monomer pairs (10). Carbonylative polymerization of aromatic dibromides and aromatic diamines is carried out under an atmosphere of carbon monoxide and in the presence of a palladium catalyst, l,8-diazabicyclo[5,4,0]-7-undecene ( D B U ) , and phosphine ligands. A dipolar aprotic solvent was used at a polymerization temperature of 115 °C. The polymers produced had inherent viscosities ranging from 0.2 to 0.8 d L / g . Higher molecular weight aramids were prepared using aromatic diiodides as substrates in place of aromatic dibromides under higher C O pressure (//). Transition metals have also been employed as complexing agents to increase the solubility of aramids. The low solubility of aramids often neces sitates extreme synthesis and processing conditions. Recently, a new method involving chromium carbonyl-arene complexation has been reported which affords improved solubility and processability (12). Polycondensation of (p-phenylenediamine)Cr(CO) with terephthaloyl chloride in Ν,Ν-dimethylacetamide proceeded as a homogeneous solution to yield high molecular weight poly(p-phenylene terephthalamide)Cr(CO) complex. Sol ution casting afforded a strong, air-stable polymer film. Decomplexation of the chromium from the aramid was effected by heating or oxidation with iodine. 3

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In Step-Growth Polymers for High-Performance Materials; Hedrick, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1996.

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STEP-GROWTH POLYMERS FOR HIGH-PERFORMANCE MATERIALS


Polyesters Aromatic polyesters have been prepared by condensation of aromatic diacid chlorides and silylated bisphenols in the presence of chloride ions as a catalyst (13). Lower temperatures were employed than those required for polymerization of acetylated diphenols and aromatic carboxylic acids, affording less side products and higher molecular weights in some cases (14J5). Similarly, trimethylsilyl 4-acetoxybenzoate can be polymerized at temperatures between 350-400 °C in Marlotherm-S to give poly(4-hydroxybenzoate) (Scheme II) (16). In this case, the silyl monomer is lower in reactivity than 4-acetoxybenzoic acid, which is normally used to prepare poly(4-hydroxybenzoate). Polymerization of the trimethylsilyl ester requires higher temperatures and gives lower polymer yields due to lower reactivity relative to the free acid monomer. However, the trimethylsilyl ester route affords highly crystalline poly(4-hydroxybenzoate) with a whisker-like morphology. This was attributed to the formation of fewer side-products than the polymerization of 4-acetoxybenzoic acid, which allows the generation of more perfect crystals than the poly(4-hydroxybenzoate) whiskers.

Polycarbonates Polycarbonates derived from bisphenol-A are important commercial thermoplastics. In order to expand the potential applications of aromatic polycarbonates, significant research has been devoted towards improving the heat resistance while maintaining the other desirable properties of bisphenol-A polycarbonate. One approach to increasing the dimensional stability of bisphenol-A polycarbonate ( T = 1 5 0 ° C ) is to introduce pendent methyl groups to the polymer backbone. Polycarbonates of tetramethyl bisphenol-A have been reported and display an increase in T to 203 °C, however, with a concomitant reduction in ductility and impact strength (17). Recently, Freitag reported the use of a new bisphenol derived from hydrogenated isophorone, 4,4 -trimethylcyclohexylidene)diphenol, T M C (18) (Scheme III). The T M C polycarbonate has a T of 239 °C, while ductility and melt processability are maintained. The T M C polycarbonate and copolymers with bisphenol-A are commercial polymers marketed by Bayer as Apec H T resins. A n important advancement in the synthesis of polycarbonates in recent years is the polymerization of cyclic oligocarbonates (19). The cyclic precursors are synthesized by a trialkylmine-catalyzed, pseudo-high dilution hydrolysis/condensation reaction of bisphenol-A chloroformate. The oligomers are formed in 85 - 9 0 % , with high polymer as the side product, and are comprised of between 2 and 20 bisphenol-A carbonate repeat units. The oligomers are polymerized to high polymer in the presence of an appropriate catalyst. This methodology has the advantage of allowing the processing of the low viscosity cyclic oligomers, which can be polymerized in a subsequent step without outgassing of volatile products of polymerization. Aliphatic polycarbonates have been investigated as potential ceramic binders, and in high resolution photoresist schemes. These applications rely on the clean thermal degradation of aliphatic polycarbonates, which is accelerated in the presence of photogenerated acids. The use of solid-liquid phase transfer catalysis in conjunction with bis(carbonylimidazolides) (20) or bis(pg

g

,

g


18.

LABADIE ET AL.


nitrophenylcarbonates) (21) was developed by Frechet for the synthesis of novel tertiary copolycarbonates (Scheme IV). The instability of tertiary chloroformâtes renders tertiary polycarbonates inaccessible through conventional chloroformate monomers or intermediates. The bis(carbonylimidazolide) monomer was shown to polymerize with both tertiary and secondary alcohols, demonstrating the utility of the method in forming polycarbonates from less reactive sterically hindered monomers.


Poly(formal)s Polyformals of bisphenols and dichloromethane were prepared by polyetherification in dimethylsulfoxide at 80 °C (22). The poly(formal)s of bisphenol-A, tetramethylbisphenol-A ( T M B A ) , and their copolymers were generated by this method. High molecular weight polymers were obtained, except in the case of T M B A homopolymers where crystallization led to premature precipitation. Incorporation of 70% T M B A afforded an increase in T from 88 °C to 113 °C. The 1,4-dihydroxy-2-cyclohexenols were prepared under phase-transfer conditions with dibromomethane (23). These polymers were evaluated as self-developable resists. g

Poly(phenylene Sulfide)s Poly(phenylene sulfide) (PPS) is an important engineering thermoplastic which is produced by the polymerization of sodium sulfide-hydrate and ρ-dichlorobenzene at 2 0 0 - 2 8 0 °C in N M P (24) (Scheme V ) . The classical synthesis, characterization and properties of PPS has been reviewed (25). In recent years, research on the mechanism of PPS formation, and several new routes to PPS have been reported and will be surveyed here. Proposals for the mechanism of PPS formation include nucleophilic aromatic substitution ( S A r ) (26), radical-cation (27), and radical-anion processes (28,29). Some of the interesting features of the polymerization are that the initial reaction of the sodium sulfide-hydrate with N M P affords a soluble NaSH-sodium 4-(N-methylamino)butanoate mixture, and that polymers of higher molecular weight than predicted by the Caruthers equation are produced at low conversions. Mechanistic elucidation has been hampered by the harsh polymerization conditions and poor solubility of PPS in common organic solvents. A detailed mechanistic study of model com pounds by Fahey provided strong evidence that the ionic S A r mechanism predominates (30). Some of the evidence supporting the S A r mechanism was the selective formation of phenylthiobenzenes, absence of disulfide pro duction, kinetics behavior, the lack of influence of radical initiators and inhibitors, relative rate Hammet values, and activation parameters consistent with nucleophilic aromatic substitution. The radical-anion process was not completely discounted and may be a minor competing mechanism. A n alternative route to PPS involves polymerization of p-halothiophenols as A - B monomers (26). Copper 4-bromothiophenoxide polymerizes to PPS in quinoline or quinoline/pyridine mixtures at temperatures of 2 0 0 - 2 3 0 °C and atmospheric pressures (31). Mechanistic studies support that polymerization of the copper salt proceeds by an S I radical-anion mechanism at the early stages of the reaction and may contribute in the later stages of polymerization as well (32). Debromination has been observed as a molecular weight limN

N

N

R N


297


298

F MeoSiHNvJv-NHSiMeo _ J © C 3

3

-2Me SiCI 3

+ C I C ~ A r - C - CI n n

'


F

F ^ F

Scheme I.

Scheme II.

0 CH- CH, 0 II i I II X - C - 0 - C - R - C - O C - X I I CH C H PTC --0 + HO-R'-OH

3

A

3

X

3

Î" Î" A " O - CI - R - C I - 0 CH CH 3

X

0-R-

3

R= CH CH -,-©2

X

= -C

N

2

,-0^0>-N0

2

Scheme IV.


18.

LABADIE ET AL.

Recent Advances in Step-Growth Polymerization299

iting side reaction which can be eliminated by carrying out the polymerization between 180-200 °C (33). A similar dechlorination process has been observed in poly(aryl ether) synthesis and has been attributed to an S I - t y p e mechanism (34). Melt polymerization of diiodobenzene with elemental sulfur in the pres ence of air, followed by further heating in the solid state affords high molec ular weight PPS with the extrusion of iodine (35) (Scheme VI). The resulting PPS is nearly equivalent to commercial PPS, with the exception that a low level of disulfide linkages are retained, and much lower levels of ionic impuri ties are present in the isolated polymer. The polymerization mechanism appears radical in nature, which was substantiated by an electron paramagnetic resonance spectroscopic study of the polymerization (36). A related route to high molecular weight PPS involves thermolysis of bis(4-iodophenyl disulfide) in diphenyl ether at 2 3 0 - 2 7 0 °C (37). The method was also applied to the synthesis of poly(naphtylene sulfides). This procedure was extended to bromide analogs through the addition of ΚI (37b,38). Diphenyl disulfides have been converted to oligo(phenylene sulfides) using either cationic (39) or oxidative polymerization conditions (40). The oxidative polymerizations have been reported in the presence of either hydroquinones (40a) or a oxovanadium/oxygen catalyst system (40b). The polymerizations are carried out in chlorinated solvents at room temperature, which limits the molecular weight obtainable to 1,000 daltons due to oligomer precipitation. The oligomers have phenyl disulfide end groups and can be functionalized with an iodophenoxyisophthalic acid end group and converted to polyamide-graft-oligophenylene sulfide copolymers (41). High molecular weight poly(phenylene sulfide) has been prepared by oxidative polymerization of methyl-4-(phenylthio)phenyl sulfoxide in trifluoromethane sulfonic acid to afford poly(sufonium cation) as a soluble precursor polymer (42) (Scheme VII). This material was subsequently demethylated in refluxing pyridine to afford PPS which precipitated as deprotection neared completion. This meth odology was extended to methyl phenyl sulfide, where the sulfide was oxidized to the sulfoxide in situ (43).


NR

Polyenaminonitriles Polyenaminonitriles are a unique class of step-growth polymers that rely on the condensation of bis(chlorovinylidene cyanide) monomers with aromatic (44) or aliphatic diamines (45) (Scheme VIII). The strong electronwithdrawing nature of the nitrile groups impart reactivity similar to a carbonyl group to the vinylidene cyanide moiety. The polyenaminotriles are soluble, processable materials which can be subsequently cyclized thermally to a poly(aminoquinoline). This situation is similar to that of polyimides, where poly(amic acid) precursor polymers are used, however, no volatile side products are released in the enaminonitrile to aminoquinoline transformation. The chemistry of the chlorovinylidene cyanide group has been extended to reactions with arylhydrazines and utilized in the synthesis of polypyrazoles (46). Poly(p-phenyl Vinylene). With the discovery that poly(p-phenylvinylene) (PPV) can be used in polymeric light emitting diodes (47), these materials



300


C I ^ C I

+

Na S-H 0 2

2

200-280Î

{^s}

n

"

Scheme V .

81-0-1

+ S

8

.

^0_j_ , s

+8 2

Scheme VI.

®-S-®-S-Me Me Pyridine, Δ

« κ , Scheme VII.



18.

LABADIE ET AL.


301

have recently attracted a great deal of interest. Classical step-growth polymerization methods for P P V synthesis, e.g., Wittig and Knoevenagel condensation, have been reviewed (48). A problem inherent with these syn thetic methods is the insoluble nature of P P V , which leads to premature pre cipitation. One approach used to overcome this problem is to incorporate alkoxy groups on the aromatic ring of P P V (49). Alternatively, benzylsubstituted poly(xylylene) precursor polymers have been shown to afford P P V after a thermal or chemical step. Xylylene chloride (50) and Xylylene sulfonium salts (51) have been used as monomers and are polymerized in the presence of base (Scheme I X ) . Transition-metal catalyzed coupling has also been utilized as a route to P P V systems and is reviewed in the chapter describing this polymerization method. Benzocyclobutene Polymers Polymers derived from monomers containing the benzocyclobutene moiety were reported independently by Kirchoff and Hahn at Dow (52) and Arnold (53). The Dow workers have focused on bisbenzocyclobutene monomers (BCBs) containing a,/?-alkenyl and bis(alkenylsiloxane) linkages between the benzocyclobutene moieties (Scheme X ) , whereas Arnold reported maleimideand phenylethynyl-benzocyclobutene copolymers. Dow has commercialized several B C B systems for microelectronics applications. The Dow B C B s are prepolymerized to processable oligomers, which are cured to the final network after film deposition without outgassing of volatiles. The polymerization chemistry is based on thermal opening of the cyclobutane ring to afford an o-quinodimethane reactive intermediate. The o-quinodimethane can undergo either Diels-Alder reactions with alkenes, alkynes or self-reaction to give cyclic dimers or linear polymer (Scheme X I ) . Mechanistic studies on arylvinylbenzocyclobutene (54) and B C B (55) demonstrated that Diels-Alder addition of the o-quindimethane to the alkene is the predominate reaction pathway. In cases where one double bond is present per two benzocyclobutene units, quinodimethane self-reaction ensues after consump tion of the double bonds by the Diels-Alder process. A high degree of DielsAlder reaction was also observed in the copolymerization of bismaleimide and BCBs (53c). Self-polymerization of an A - B benzocyclobutene-phenylethynyl phtthalimide monomer occurred with a mixture of cross- and selfcondensation of the reactive endgroups (53a). Perfluorocyclobutane Aromatic Polyethers Novel polymers containing alternating perfluorocyclobutane and aromatic ether subunits have been prepared by polymerization of aryl trifluorovinyl ether monomers via the thermal [in + 2 π ] cyclodimerization of the trifluorovinyl ether functionality (Scheme X I I ) (56). The dimerization of the trifluorovinyl ether moiety is not a concerted pericyclic reaction, rather pro ceeds through a diradical intermediate. Dimerization affords predominately 1,2-substituted perfluorocyclobutane rings with a mixture of cis and trans isomers. Both linear and crosslinked polymer systems were synthesized using bis- and tris(trifluorovinyoxy) monomers, respectively. These polymers display both a low dielectric constant ( < 2.5) and very low moisture absorp tion.



302


Jn Scheme VIII.

1) NaOH

OMe 0

X CH -O-CH X® Cl 9

9

(;

OMe

OMe

-f^-CH CH^) Sodium toluenesulfonate π OMe 3) CH 0H 230 °C

2

2

v

n

3

x= s O

OMe

9 OMe Scheme IX.

I I R= ^

,— S i - O S i — CH

3

CH

·

—0—

3

Scheme X .


18. LABADIE ET AL.

Recent Advances in Step-Growth Polymerization R

303

R

^ OCX Scheme XI.


F

F

r^0-Ar-0^V F h

h

Ρ

F

—^—

F F 4 A r - 0 — C - C - 0 1

1

CF -CF 2

2

Scheme XII.

Literature Cited 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

Yang, H. H. Aromatic High Strength Fibers; Wiley: New York, 1989. Sekiguchi, H.; Coutin, B. In Handbook of Polymer Synthesis, Part A; Kricheldorf, H. R., Ed.; Dekker: New York, 1992; p. 807. Volbracht, L. Comprehensive Polymer Science; Allen, G., Bevington, J. C., Eds.; Pergamon: Oxford, 1989; Vol. 5, p. 375. Imai, Y. Makromol. Chem., Macromol. Symp. 1992, 54/55, 389. Oishi, Y.; Harada, S.; Kakimoto, M.; Imai, Y. J. Polym. Sci., Part A, Polym. Chem. 1992, 30, 1203. Oishi, Y.; Kakimoto, M.; Imai, Y. J. Polym. Sci., Part A, Polym. Chem. 1987, 25, 2493. Otsuki, T.; Kakimoto, M.; Imai, Y. J. Polym. Sci., Part A, Polym. Chem. 1989, 27, 1775. Memeger, W., Jr.; Lazar, J.; Ovenall, D.; Leach, R. A. Macromole cules 1993, 26, 3476. Heck, R. F. Palladium Reagents in Organic Syntheses; Academic: New York, 1985; p. 18. Yoneyama, M.; Kakimoto, M.; Imai, Y. Macromolecules 1988, 21, 1908. Perry, R.; Turner, S. R.; Blevins, B. W. Macromolecules 1993, 26, 1509. Dembek, Α. Α.; Burch, R. R.; Feiring, A. E. J. Am. Chem. Soc. 1993, 115, 2087. Kricheldorf, H. R. Makromol. Chem., Macromol. Symp. 1992, 54/55, 365. Kricheldorf, H. R.; Englehardt, J. J. Polym. Sci., Part A 1988, 26, 1621. Kricheldorf, H. R.; Weegen-Schulz, B.; Englehardt, J. Makromol. Chem. 1991, 192, 631. Kricheldorf, H. R.; Schwarz, G.; Ruhser, F. Macromolecules 1991, 24, 3485. Morbitzer, L.; Grigo, U. Angew. Makromol. Chem. 1988, 162, 87.


304 STEP-GROWTH POLYMERS FOR HIGH-PERFORMANCE MATERIALS

18. 19.

20. 21.


22. 23.

24. 25. 26. 27.

28.

29. 30. 31. 32. 33. 34.

35.

36. 37.

38.

Freitag, D.; Westeppe, U. Makromol. Chem., Rapid Commun. 1991, 12, 95. (a) Brunelle, D. J.; Boden, E. P.; Shannon, T. G. J. Am. Chem. Soc. 1990, 112, 2399; (b) Brunelle, D. J.; Boden, E. P. Makromol Chem., Makromol Symp. 1992, 54/55, 397. Houlihan, F. M.; Bouchard, F.; Frechet, J. M. J.; Willson, C. G. Macromolecules 1986, 19, 13. Frechet, J. M. J.; Bouchard, F.; Houlihan, F. M.; Eichler, B.; Kryczka, B.; Willson, C. G. Macromol. Chem. Rapid. Commun. 1986, 7, 121. Andolino Brandt, P.J.; Senger, E.; Patel, N.; York, G.; McGrath, J. E. Polymer 1990, 31, 180. Frechet, J.M. J.; Willson, C. G.; Iizawa, T.; Nishikubo, T.; Igarashi, K.; Fahey, J. ACS Symposium Series 412, Polymers in Microelec tronics, Materials and Processes; Reichmanis, E., MacDonald, S. Α., Iwayagami, T., Eds.; American Chemical Society: Washington, D.C., 1989; Chap. 7, p. 100. Edmonds, J. T.; Hill, H. W. U.S. Patent 3,354,129. Lopez, L. C.; Wilkes, G. L. J.M.S.-Rev. Macromol. Chem. Phys. 1989, C29, 83. Lenz, R. W.; Handlovits, C. E.; Smith, H. A. J. Polym. Sci. 1962, 58, 351. (a) Koch, W.; Heitz, W. Makromol. Chem. 1983, 184, 779; (b) Koch, W.; risse, W.; Heitz, W. Makromol. Chem. Suppl. 1985, 12, 105. (a) Annenkova, V. Z.; Antonik, L. M.; Vakulshaya, T. I.; Voronkov, M. G. Dohl. Akad. Navk. SSR 1986, 286, 1400; (b) Annenkova, V. Z.; Antonik, L. M.; Shafeeva, I. V.; Vakulskaya, T. I.; Vitkovskii, V. Y.; Voronkov, M. G. Vysokomol. Soed., Ser. Β 1986, 28, 137. Burnett, J. F. ACC Chem. Res. 1978,11,413. Fahey, D. R.; Ash, C. E. Macromolecules 1991, 24, 4242. (a) Port, A. B.; Still, R. H. J. Appl. Polym. Sci. 1979, 24, 1145; (b) Lovell, P. Α.; Still, R. M. Makromol. Chem. 1987, 188, 1561. Lovell, P. Α.; Archer, A. C. Makromol. Chem., Macromol. Symp. 1992, 54/55, 257. Archer, A. C.; Lovell, P. A. Polymer International 1994, 33, 19. (a) Percec, V.; Clough, R. S.; Rinaldi, P. L.; Litman, V. E. Macro molecules 1991, 24, 5889; (b) Percec,V.; Clough, R. S.; Grigoras, M.; Rinaldi, P. L.; Litman, V. E. Macromolecules 1993, 26, 3650; (c) Mani, R. S.; Zimmerman, B.; Bhatnager, Α.; Mohanty, D. K. Polymer 1993, 34, 171. (a) Rule, M.; Fagerburg, D. R.; Watkins, J. J.; Lawrence, P. B. Makromol. Chem., Rapid Commun. 1991, 12, 221; (b) Rule, M.; Fagerburg, D. R.; Watkins, J. J.; Lawrence, P. B.; Zimmerman, R. L.; Cloyd, J. D. Makromol. Chem., Macromol. Symp. 1992, 54/55, 233. Lowman, D. W.; Fagerburg, D. R. Macromolecules 1993, 26, 4606. (a) Wang, Ζ. Y.; Hay, A. S. Macromolecules 1991, 24, 333; (b) Wang, Ζ. Y.; Hay, A. S. Makromol. Chem., Macromol. Symp. 1992, 54, 247. Tsuchida, E.; Yamamoto, K.; Jikei, M.; Miyatake, K. Macromole cules 1993, 26, 4113. In Step-Growth Polymers for High-Performance Materials; Hedrick, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1996.

18. LABADIE ET AL. Recent Advances in Step-Growth Polymerization 305 39.

40.

41.


42. 43. 44.

45. 46. 47.

48. 49.

50.

51.

52.

53.

54. 55. 56.

(a) Tsuchida, E.; Yamamoto, Κ.; Nishide, Η.; Yoshida, S. Macro molecules 1987, 20, 2031; (b) Tsuchida, E.; Yamamoto, K.; Nishide, H.; Yoshida, S.; Jikei, M. Macromolecules 1990, 23, 2101. (a) Tsuchida, E.; Jikei, M. Macromolecules 1990, 23, 930; (b) Yamamoto, K.; Tsuchida, E.; NIshide, H.; Jikei, M.; Oyaizu, K. Macromolecules 1993, 26, 3432. Tsudida, E.; Yamamoto, K.; Oyaizu, K.; Suzuki, F.; Hay, A. S.; Wang, Z. Y. Macromolecules 1995, 28, 409. Tsuchida, E.; Shouji, E.; Yamamoto, K. Macromolecules 1993, 26, 7144. Tsuchida, E.; Suzuki, F.; Shouji, E.; Yamamoto, K. Macromole cules1994,27, 1057. (a) Moore, J. Α.; Robello, D. R. Macromolecules 1989, 22, 1084; (b) Moore, J. Α.; Kim, S. Y. Makromol Chem.,Macromol.Symp. 1992, 54/55, 423; (c) Moore, J. Α.; Mehta, P. G. Macromolecules 1995, 28, 854. Moore, J. Α.; Mehta, P. G.; Kim, S. Y. Macromolecules 1993, 26, 3504. Moore, J. Α.; Mehta, P. G. Macromolecules 1995, 28, 444. Burroughs, J. M.; Bradley, D. D. C.; Brown, A. R.; Marks, R. N.; Mackay, K.; Friend, R. H.; Burns, P. L.; Holmes, A. B. Nature 1990, 347, 539. Hörhold, H.-H.; Helbig, M. Makromol. Chem.,Macromol.Symp. 1987, 12, 229 (a) Lenz, R. W.; Han, C. C.; Lux, M. Polymer 1989, 30, 1041; (b) Askari, S. H.; Rughooputh, S. D.; Wadl, F.; Megen, A. J. Polymer Preprints 1989, 30, 157. (a) Gilch, H. G.; Wheelwright, W. L. J. Polym. Sci., Part A-l 1966, 4, 1337; (b) Swatos, W. J.; Gordon, B. Polymer Preprints 1990, 31(1), 505; (c) Sarnecki, G. J.; Burn, P. L.; Kraft, Α.; Friend, R. H.; Holmes, A. B. Synthetic Metals 1993, 55, 914. (a) Lahti, P. M.; Modarelli, D. Α.; Denton, F. R.; Lenz, R. W.; Karasz, F. E. J. Am. Chem. Soc. 1988, 110, 7258; (b) Tokito, S.; Smith, P.; Heeger, A. J. Polymer 1991, 32, 464. (a) Kirchoff, R. Α.; Carriere, C. J.; Bruza, K. J.; Rondon, N. G.; Sammler, R. L. J. Macromol. Sci.-Chem. 1991, A28, 1079; (b) Hahn, S. F.; Townsend, P. H.; Burdeaux, D. C.; Gilpin, J. A. Polymeric Materials for Electronics and Interconnections; Lupinski, J. H., Moore, R. S., Eds.; ACS Symposium Series 407; American Chemical Society: Washington, D. C., 1989. (a) Tan, L. S.; Arnold, F. E. J. Polym. Sci., Polym. Chem. Ed. 1987, 25, 3159; (b) Tan, L. S.; Arnold, F. E. J. Polym. Sci., Polym. Chem. Ed. 1988, 26, 1819; (c) Tan, L. S.; Arnold, F. E. J. Polym. Sci., Polym. Chem. Ed. 1988, 26, 3103. Hahn, S. F.; Martin, S. J.; McKelvy, M. L. Macromolecules 1992, 25, 1539. Hahn, S. F.; Martin, S. J.; McKelvy, M. L.; Patrick, D. W. Macro molecules 1993, 26, 3870. Babb, D. Α.; Ezzell, B. R.; Clement, K. S.; Richey, W. F.; Kennedy, A. P. J. Polym. Sci., Polym. Chem. Ed. 1993, 31, 3465.

RECEIVED January 25, 1996


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