Letter pubs.acs.org/macroletters
Nitroxide-Mediated Alternating Copolymerization of Vinyl Acetate with tert-Butyl-2-trifluoromethacrylate Using a SG1-Based Alkoxyamine Sanjib Banerjee,*,† Ilaria Domenichelli,‡,§ and Bruno Ameduri*,† †
Ingénierie et Architectures Macromoléculaires, Institut Charles Gerhardt, UMR 5253 CNRS, UM, ENSCM, Place Eugéne Bataillon, 34095 Montpellier Cedex 5, France ‡ Isituto di Chimica dei Composti Organometallici (ICCOM), Consiglio Nazionale delle Ricerche, SS Pisa, Via G. Moruzzi 1, 56124 Pisa, Italy § Scuola Normale Superiore, Piazzadei Cavalieri 7, 56126 Pisa, Italy S Supporting Information *
ABSTRACT: Unique alternating copolymers based on vinyl acetate (VAc) and tert-butyl-2-trifluoromethacrylate (MAFTBE, a nonhomopolymerizable monomer under radical conditions) have been synthesized by nitroxide-mediated polymerization (NMP) using a SG1-based BlocBuilder alkoxyamine (MAMA-SG1) at moderate temperature (at 40 °C) in dimethyl sulfoxide. First-order kinetics and linear evolutions of the molecular weight (up to 17100 g mol−1), maintaining low dispersity values (Đ ≤ 1.33), confirmed the controlled nature of the copolymerization. Interestingly, none of the starting monomers could undergo homopolymerization under the NMP condition initiated by MAMA-SG1. The resulting alternating copolymers were characterized by 1H, 13C, 19F, and 31P NMR spectroscopies and size exclusion chromatography (SEC). The poly(VAc-alt-MAF-TBE) copolymer is amorphous and exhibited a single glass transition temperature of 59 °C. This is the first report of nitroxide-mediated (co)polymerization of VAc leading to well-defined copolymers with satisfactory yields. The results presented in this study established a new route via NMP toward the synthesis of strictly 1:1 alternating fluorocopolymers that can display diverse functionalities.
D
signed monomers to prepare unprecedented sequence-regulated copolymers with perfect vinyl chloride−styrene−acrylate sequences. Recent attempts by Studer’s group17 and the Scherf’s team18 toward the synthesis of alternating copolymers composed of hexafluoroisopropyl acrylate/7-octenyl vinyl ether and N-dialkylated benzothiadiazolodithienopyrrole/a dibrominated terephthalophenone derivative, respectively, have failed to achieve exclusive alternating copolymerization. Thus, for new monomer pairs, highly ordered monomer sequence control has been very difficult to achieve. Poly(vinyl acetate) (PVAc) has applications in adhesive emulsions, as a protective coating. VAc is also used as a raw material to manufacture industrially important polymers such as poly(vinyl alcohol), poly(vinyl acetate phthalate), and ethylene−vinyl acetate (EVA).19 Predominantly alternating free radical copolymerization of VAc was only achieved with few monomers, namely, maleic anhydride,20 benzylidenemalononitrile,21 ethyl α-cyanocinnamate,22 acrylic acid,23 hexafluoroiso-
uring the last two decades, extensive research and development of different reversible deactivation radical polymerization (RDRP) techniques1−4 enabled facile synthesis of macromolecules with complex and controlled architecture. This development has led to the realization that synthetic polymers are fundamental to achieve the functions of natural macromolecules bearing fully well-defined “monomer” sequences (such as in proteins and nucleic acids). However, compared to the natural macromolecules, monomer sequence regulation in synthetic polymers has been a formidable challenge.5,6 Successful monomer sequence control in synthetic polymers may allow fine-tuning of their structures, properties, and functions, leading to promising new applications in catalysis, molecular recognition, or biodegradable materials.7 Alternating radical copolymerization leads to (A-B)n type copolymers suitable for application in photovoltaic devices.8 But, up to this date, exclusive alternating radical polymerization has been reported only for a few monomer pairs, such as styrene/maleic anhydride,9,10 styrene/maleimide derivatives,11 styrene/methacrylates,12 vinyl ethers/methacrylates,13 and chlorotrifluoroethylene/vinyl ethers.14,15 Kamigaito’s group16 has employed copper-catalyzed step-growth radical polymerization of de© XXXX American Chemical Society
Received: September 16, 2016 Accepted: October 17, 2016
1232
DOI: 10.1021/acsmacrolett.6b00707 ACS Macro Lett. 2016, 5, 1232−1236
Letter
ACS Macro Letters butylene,24 and halogen ring-substituted methyl 2-cyano-3phenyl-2-propenoates.25 VAc has also been reported to undergo free radical copolymerization with few fluoromonomers, such as tetrafluoroethylene (TFE),26 chlorotrifluoroethylene (CTFE),27 and vinylidene fluoride (VDF).28 But, in all these reports, largely random copolymers were obtained with uncontrolled molecular weight, dispersity values, and undefined chain end functionalities. Fluorinated copolymers containing 2-(trifluoromethyl)acrylic acid (MAF) and alkyl 2-trifluoromethacrylates (MAF-esters) lead to extensive applications in molecularly imprinted polymers, microlithography, polymer gel electrolyte membranes for fuel cells, and polymer electrolytes in Li-ion batteries.29 MAF or MAF-esters do not undergo homopolymerization under radical conditions.29−31 In contrast, anionic homopolymerizations of MAF or MAF-esters were reported.32 Nevertheless, radical copolymerizations of electron-withdrawing MAF or MAF-esters have been successfully achieved with electron-donating α-olefins,33 norbornenes,34,35 and vinyl ethers.34,36 However, to the best of our knowledge, there is no report on the radical copolymerization of MAF or MAFesters with VAc. All the earlier attempts of radical copolymerization of VAc with acrylates led only to random copolymers.37−39 Zaremski et al.40 reported TEMPO-mediated copolymerization of VAc with styrene. However, the polymerization was noticeably slower and not well-controlled. Reversible-deactivation radical polymerization (RDRP) of VAc was achieved via RAFT/MADIX,41 iodine transfer polymerization,42 and cobalt-mediated radical polymerization (CMRP).43 Alternating radical copolymerization of VAc with tert-butyl-2-trifluoromethacrylate (MAF-TBE) via RDRP technique may produce interesting polymer materials comprised of two different monomers of opposed reactivities: an electron-donating monomer, VAc (D), and an electronwithdrawing (or accepting) monomer, MAF-TBE (A). Furthermore, the tunability of the resulting materials could be improved by the possibility to control the chain length, the dispersity values and the topology by using RDRP techniques. This could lead to lead to a large variety of conceivable new materials with interesting properties (e.g., enhanced hydrophobicity) and further cross-linking44 for high-tech applications (e.g., functional coatings or membranes). Nitroxide-mediated polymerization (NMP) has been a popular RDRP technique for a very broad range of monomer families including styrenics, acrylates, methacrylates, vinyl chloride, and so on.4,45,46 Recently, Ballard et al.47 reported the development of a new class of alkoxyamines for efficient controlled homopolymerization of methacrylates. However, homopolymerization of VAc has never been reported by NMP because the initially formed oligo(VAc) chains are irreversibly trapped by the nitroxide, and this C-ON bonded chain-ends cannot be cleaved at a reasonable temperature to allow the formation of macroradicals able to favor propagation.48 In this context, we report for the first time the effective use of a commercially available SG1-based alkoxyamine BlocBuilder (MAMA-SG1) to achieve nitroxide-mediated 1:1 alternating radical copolymerization of VAc (donor, D) and MAF-TBE (acceptor, A; Scheme 1). The homopolymerizations of VAc and MAF-TBE using MAMA-SG1 at 40 °C, as well as at 65 °C in DMSO failed, as expected from the earlier reports (entries 1−4, Table S1).29−31,48 However, MAF-TBE (A) is known to undergo alternating radical copolymerization with electron-donating α-
Scheme 1. Synthesis of Poly(VAc-alt-MAF-TBE) Alternating Copolymers by NMP Using MAMA-SG1
olefins,33 norbornenes,34,35 and vinyl ethers34,36 and VDF.29,49 Thus, we expected it to undergo copolymerization with VAc. To test this hypothesis, the nitroxide-mediated copolymerization of VAc with MAF-TBE was carried out using MAMA-SG1 (Scheme 1 and Table S1) in DMSO at 40 °C (entry 5, Table S1) and 65 °C (entry 6, Table S1). The progress of the reaction was monitored by 1H (equation S1, to determine VAc conversion) and 19F (equation S2, to measure MAF-TBE conversion) NMR spectroscopies, respectively. Figures S1 and S2 exhibit representative stack plots of such 1H and 19F NMR kinetic experiments. Equimolar conversions of VAc and MAFTBE were recorded (Figure 1A and Figure S3), suggesting highly alternating copolymerizations (entry 5, Table S1). The 1 H NMR spectra (Figure S1) display a multiplet centered at 5.10 ppm corresponding to the methyne group of VAc in the VAc-MAF-TBE alternating dyad. This is different from the methyne group of VAc in the PVAc homopolymer that appears at 4.80 ppm.50 The semilogarithmic kinetic plot of this copolymerization (Figure 1B) shows a linear tendency indicating that the copolymerization followed first order kinetics. However, when the polymerization was carried out at 65 °C, the reaction was very fast, nevertheless it maintained equimolar conversions of both monomers (compare Figures 1, S3, and S4 with Figures S5 and S6). The loss of linearity in the ln([M]0/[M]) versus time plot at 65 °C is probably due to the dramatic increase of the viscosity of the reaction medium. The SEC traces (Figure 2A) display a monomodal behavior throughout the copolymerization, exhibiting a linear increase of molar mass (Mn) with monomer conversion, maintaining low dispersity values (Đ ≤ 1.33; Figure 2B). Notably, the experimentally measured Mn values were close to the theoretical ones. These features are consistent with a RDRP process. As expected, Đ values of the polymers obtained by polymerization at 65 °C (Figure S7) was comparatively higher than those achieved at 40 °C (Figure 2A), due to very fast polymerization at 65 °C, as evidenced from the kinetic plots (Figure S6). Polymerizations performed in dichloromethane (entry 7, Table S1) led to very poor yield (9% in 36 h) and higher Đ values (≥1.53), in contrast to well-controlled NMP of vinyl chloride in dichloromethane.46 Confirmation of the alternating structure was supported by detailed 1H, 19F, 31P, 13C, and 2D NMR characterizations 1233
DOI: 10.1021/acsmacrolett.6b00707 ACS Macro Lett. 2016, 5, 1232−1236
Letter
ACS Macro Letters
Figure 2. Evolutions of SEC traces vs. time (A) and Mn and Đ as a function of the total monomer conversion (B) for the nitroxidemediated alternating copolymerization of VAc with MAF-TBE using MAMA-SG1 ([VAc]0/[MAF-TBE]0/[MAMA-SG1]0 = 90/90/1) at 40 °C in DMSO (entry 5, Table S1).
Figure 1. No. of mmol of monomers consumed vs time (A) and ln[M]0/[M] vs. time (B) plots for the nitroxide-mediated alternating copolymerization of VAc with MAF-TBE using MAMA-SG1 ([VAc]0/ [MAF-TBE]0/[MAMA-SG1]0 = 90/90/1) at 40 °C in DMSO (entry 5, Table S1).
(Figures 3 and S8−S13). The 1H NMR spectrum of the pure poly(VAc-alt-MAF-TBE) alternating copolymers (Figure 3) shows four characteristic signals: (i) those corresponding to the α-end group (MAMA fragment) generated during the initiation process: signals h (1.13 ppm); (ii) those attributed to the ωend group (SG1 fragment) generated during the end-capping process: signals d (0.85 ppm), e (ca. 1.10 ppm), f (ca. 1.24 ppm), and g (ca. 4.10 ppm); (iii) signals assigned to the VAc units: signal a (ca. 5.10 ppm), attributed to −CHOAc in the VAc-MAF-TBE alternating dyad, as observed in the cases of other alternating copolymers containing VAc,21,25,51,52 and signal c (ca. 1.9 ppm), characteristic of the −OCOCH3, signal b (ca. 2.0 ppm), attributed to −CH2, and signal i (ca. 6.55 ppm), corresponding to −CHOAc in the VAc attached to the SG1 at the ω-end group; and (iv) signals assigned to the MAF-TBE units: signal a′ (ca. 1.40 ppm) characteristic of the −C(CH3)3 of MAF-TBE, signal b′ (ca. 2.21 ppm) corresponding to −CH2, which overlaps with −CH2 of VAc unit). Since a MAF-TBE radical can not react with a MAF-TBE monomer,30,31 every MAF-TBE unit must therefore have VAc units on each side (Scheme 1). Notably, that 1H NMR spectrum (Figure 3) shows
Figure 3. Representative 1H NMR spectrum of poly(VAc-alt-MAFTBE) alternating copolymer prepared by nitroxide-mediated alternating copolymerization of VAc with MAF-TBE using MAMA-SG1 at 40 °C in DMSO (entry 5, Table S1), recorded in CDCl3 at 20 °C. (*) Solvent (CHCl3) peak.
1234
DOI: 10.1021/acsmacrolett.6b00707 ACS Macro Lett. 2016, 5, 1232−1236
Letter
ACS Macro Letters
degradation of the alkoxyamine {bond between −CH(OAc) and SG1}, as reported by Marque et al.54 The alternating copolymer exhibited a single glass transition temperature (Tg) at 59 °C (Figure S19), which is different from Tg (35 °C) of PVAc homopolymer, as reported in the literature.55 Though synthesis of graft copolymers can be anticipated by the transesterification of the ester pendant groups, attempts to prepare block copolymers using poly(VAc-alt-MAF-TBE)-SG1 as the alkoxyamine macroinitiator and VAc (at 40 and 65 °C) and styrene (at 120 °C) as the monomers failed. This may arise from the C-ON bonded chain-ends of the poly(VAc-alt-MAFTBE)-SG1 as the alkoxyamine macroinitiator cannot be cleaved at a reasonable temperature to release macroradicals able to allow the propagation.48 In conclusion, a novel approach for the preparation of welldefined 1:1 alternating poly(VAc-alt-MAF-TBE) copolymer by NMP has been developed. Controlled behavior of the copolymerization was evidenced by linear semilogarithmic plot and linear Mn-conversion plot maintaining low Đ values. The alternating structure of the copolymer was confirmed by detailed microstructure analysis. The copolymer was amorphous and exhibited a single glass transition temperature of 59 °C. This work also reports the unprecedented alkoxyaminemediated alternating polymerization involving VAc. This unique and simple one-pot synthetic strategy should further contribute to the development of high-performance sequencespecific copolymers, a step toward advanced material properties, currently under progress.
the absence of −CHOAc signal in the PVAc homopolymer at 4.8 ppm.50 The 19F NMR spectrum (Figure S8) revealed the MAF-TBE −CF3 group signal at −69 ppm.49 In addition, the characteristic signal assigned to the phosphorus atom of the SG1 fragment in the ω-chain end of the copolymer was observed at 25 ppm in the 31P NMR spectrum (Figure S9). 13 C{1H}{19F} NMR (1H and 19F double decoupled) spectrum (Figure S10) enabled to assign the position of the carbon atoms of the poly(VAc-alt-MAF-TBE) alternating copolymer. The origin of two signals centered at 67.5 ppm, corresponding to the −CH of VAc in the VAc-MAF-TBE alternating dyad might be attributed to the fact that VAc-MAFTBE dyad displays two asymmetric carbons. Two distinct signals centered at 166.8 and 169.9 ppm were assigned to the carbonyl carbon in VAc and MAF-TBE, respectively. Comparison of 13C NMR spectra with or without 1H and 19F decoupling (Figure S11) allowed to attribute the number of H or F atoms attached to the carbon atoms the poly(VAc-altMAF-TBE) alternating copolymer. A DEPT-135 NMR experiment (Figure S12) further helped in identifying the resonance assignment to the C atom type of the alternating copolymer. The origin of two signals corresponding to the −CH of VAc in the VAc-MAF-TBE alternating dyad is attributed to the presence of stereocenters on every monomer unit. The 1 H−13C HSQC NMR spectrum (Figure S13) of the poly(VAc-alt-MAF-TBE) alternating copolymer revealed four correlations between protons and carbon atoms: (i) −C(CH3)3 protons of MAF-TBE (δH = 1.40 ppm) with carbon C(a′) at δC = 27.75 ppm, (ii) −OCOCH3 protons (δH = 1.90 ppm) with carbon C(c) at δC = 20.83 ppm, (iii) −CH2 protons of VAc and MAF-TBE (δH = 2.0 and 2.21, respectively) with carbons C(b, b′) at δC = 37.32 and 38.44 ppm, respectively, and (iv) the −CH 2 C(CF 3 )(COOt Bu)−CH 2 CH(OCOCH 3 )CH 2 C(CF 3 ) (COOtBu)-protons (δH = 5.10 ppm) with carbon at C(a) δC = 66.62 ppm. In situ NMR experiment revealed the presence of VAc adduct with MAMA-SG1. However, no such MAF-TBE/ MAMA-SG1 was formed. Hence, the polymerization starts with addition of VAc to the cleaved alkoxyamine (Figures S14 and S15). This is followed by addition of MAF-TBE and then of VAc and vice versa (Scheme 1), leading to alternating copolymerization. To gain more insight into the polymerization mechanism, we also determined the reactivity ratios of VAc and MAF-TBE (details are in SI, page S6). Whatever the monomer feed composition, the molar copolymer composition was always VAc/MAF-TBE = 1:1 (Figure S16), as revealed by the comonomer-copolymer composition curve (Figure S17). The data points of Figure S17 were fitted with the Mayo−Lewis copolymerization eq S3 to attain the following reactivity ratios: rVAc = 0.013 ± 0.011 and rMAF‑TBE = 0 at 40 °C. These near-zero values of reactivity ratios suggest exclusive cross-propagation leading to alternating copolymerization, independent of the comonomer feed. The thermal properties of the poly(VAc-alt-MAF-TBE) alternating copolymer was studied by thermogravimetric analysis and differential scanning calorimetry (DSC). A significant weight loss under air (23%) of the poly(VAc-altMAF-TBE) copolymer just above 150 °C (Figure S18) is probably due to the decomposition of the tert-butyl ester group of the copolymer into a carboxylic acid group with release of isobutene, followed by the subsequent decarboxylation of the carboxylic acid group (Scheme S1).53 There is also a
■
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsmacrolett.6b00707. Complete descriptions of experimental procedures including polymer synthesis; table of (co)polymerization results and additional analyses, including NMR spectra, SEC traces, kinetic plots, and in situ NMR experiment to assess reactivity ratios of the monomers (PDF).
■
AUTHOR INFORMATION
Corresponding Authors
*E-mail:
[email protected]. *E-mail:
[email protected]. Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS The authors thank Tosoh F-Tech Company (Shunan, Japan), Dr. Julien Nicolas and Arkema (Colombes, France) for providing MAF-TBE and MAMA-SG1, respectively. Financial support from the French national agency (ANR, ANR-14CE07-0012-02 Grant FLUPOL) is greatly appreciated. I.D. also thanks EU for providing a Mobility Grant for Higher Education Learning Agreement for traineeships, Erasmus + HE-2015.
■
REFERENCES
(1) Debuigne, A.; Poli, R.; Jerome, C.; Jerome, R.; Detrembleur, C. Prog. Polym. Sci. 2009, 34, 211−239. (2) Boyer, C.; Bulmus, V.; Davis, T. P.; Ladmiral, V.; Liu, J.; Perrier, S. Chem. Rev. 2009, 109, 5402−5436. (3) Matyjaszewski, K. Macromolecules 2012, 45, 4015−4039.
1235
DOI: 10.1021/acsmacrolett.6b00707 ACS Macro Lett. 2016, 5, 1232−1236
Letter
ACS Macro Letters
(40) Zaremski, M. Y.; Plutalova, A. V.; Lachinov, M. B.; Golubev, V. B. Macromolecules 2000, 33, 4365−4372. (41) Harrisson, S.; Liu, X.; Ollagnier, J.-N.; Coutelier, O.; Marty, J.D.; Destarac, M. Polymers 2014, 6, 1437−1488. (42) Iovu, M. C.; Matyjaszewski, K. Macromolecules 2003, 36, 9346− 9354. (43) Debuigne, A.; Caille, J.-R.; Jerome, R. Angew. Chem., Int. Ed. 2005, 44, 1101−1104. (44) Tillet, G.; Boutevin, B.; Ameduri, B. Prog. Polym. Sci. 2011, 36, 191−217. (45) Nitroxide Mediated Polymerization: From Fundamentals to Applications in Materials Science; Gigmes, D., Ed.; RSC: Oxford, 2015. (46) Abreu, C. M. R.; Mendonça, P. V.; Serra, A. C.; Noble, B. B.; Guliashvili, T.; Nicolas, J.; Coote, M. L.; Coelho, J. F. J. Macromolecules 2016, 49, 490−498. (47) Ballard, N.; Aguirre, M.; Simula, A.; Agirre, A.; Leiza, J. R.; Asua, J. M.; van Es, S. ACS Macro Lett. 2016, 5, 1019−1022. (48) Lutz, J.-F.; Lacroix-Desmazes, P.; Boutevin, B.; Le Mercier, C.; Gigmes, D.; Bertin, D.; Tordo, P. Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.) 2002, 43, 287−288. (49) Patil, Y.; Ameduri, B. Polym. Chem. 2013, 4, 2783−2799. (50) Debuigne, A.; Champouret, Y.; Jerome, R.; Poli, R.; Detrembleur, C. Chem. - Eur. J. 2008, 14, 4046−4059. (51) Kulkarni, N. G.; Krishnamurti, N.; Chatterjee, P. C.; Sivasamban, M. A. Makromol. Chem. 1970, 139, 165−170. (52) Kochi, T.; Nakamura, A.; Ida, H.; Nozaki, K. J. Am. Chem. Soc. 2007, 129, 7770−7771. (53) Wadekar, M. N.; Patil, Y. R.; Ameduri, B. Macromolecules 2014, 47, 13−25. (54) Marque, S.; Le Mercier, C.; Tordo, P.; Fischer, H. Macromolecules 2000, 33, 4403−4410. (55) Ahmad, J.; Hågg, M. B. J. Membr. Sci. 2013, 445, 200−210.
(4) Nicolas, J.; Guillaneuf, Y.; Lefay, C.; Bertin, D.; Gigmes, D.; Charleux, B. Prog. Polym. Sci. 2013, 38, 63−235. (5) Lutz, J.-F. Polym. Chem. 2010, 1, 55−62. (6) Lutz, J.-F. ACS Macro Lett. 2014, 3, 1020−1023. (7) Gratzer, W. Giant Molecules; Oxford University Press: Oxford, 2009. (8) Romulus, J.; Tan, L.; Weck, M.; Sampson, N. S. ACS Macro Lett. 2013, 2, 749−752. (9) Cloete, W. J.; Adriaanse, C.; Swart, P.; Klumperman, B. Polym. Chem. 2011, 2, 1479−1481. (10) Williams, E. G. L.; Fairbanks, B.; Moad, G.; Mulder, R. J.; Rizzardo, E.; Thang, S. H. Polym. Chem. 2015, 6, 228−232. (11) Oishi, A.; Matsuoka, H.; Yasuda, T.; Watanabe, M. J. Mater. Chem. 2009, 19, 514−521. (12) Kirci, B.; Lutz, J.-F.; Matyjaszewski, K. Macromolecules 2002, 35, 2448−2451. (13) Mishima, E.; Yamago, S. Macromol. Rapid Commun. 2011, 32, 893−898. (14) Valade, D.; Boschet, F.; Ameduri, B. Macromolecules 2009, 42, 7689−7700. (15) Boschet, F.; Ameduri, B. Chem. Rev. 2014, 114, 927−980. (16) Satoh, K.; Ozawa, S.; Mizutani, M.; Nagai, K.; Kamigaito, M. Nat. Commun. 2010, 1, 1−6. (17) Tesch, M.; Hepperle, J. A. M.; Klaasen, H.; Letzel, M.; Studer, A. Angew. Chem. Int. Ed. 2015, 54, 5054−5059. (18) Kass, K.-J.; Forster, M.; Scherf, U. Angew. Chem. Int. Ed. 2016, 55, 7816−7820. (19) Espi, E.; Salmeron, A.; Fontecha, A.; Garcia, Y.; Real, A. I. J. Plast. Film Sheeting 2006, 22, 85−102. (20) Caze, C.; Loucheux, C. J. Macromol. Sci. Chem. 1975, 9, 29−43. (21) Kharas, G.; Kohn, D. H. J. Polym. Sci., Polym. Chem. Ed. 1984, 22, 583−588. (22) Kharas, G.; Kohn, D. H. J. Polym. Sci., Polym. Chem. Ed. 1984, 22, 577−582. (23) Xu, G. J.; Meng, Y.-Z.; Song, H.; Lin, Q.-S. J. Polym. Sci., Part A: Polym. Chem. 1989, 27, 1817−1829. (24) Wu, C.; Brambilla, R.; Yardley, J. T. Macromolecules 1990, 23, 997−1004. (25) Kharas, G. B.; Barbarawi, H. A.; Crawford, A. L.; DotsonNewman, O. I.; Dukarevich, I. J.; Ekram, A.; Galzin, N. A.; Ghattas, R. M.; Hoang, J. M.; Hyland, L. A.; Isic, B.; Gutierrez, J.; Watson, K. Des. Monomers Polym. 2005, 8, 309−317. (26) Modena, M.; Borsini, G.; Ragazzini, M. Eur. Polym. J. 1967, 3, 5−12. (27) Baradie, B.; Shoichet, M. S. Macromolecules 2002, 35, 3569− 3575. (28) Panchalingam, V.; Reynolds, J. R. J. Polym. Sci., Part C: Polym. Lett. 1989, 27, 201−208. (29) Patil, Y.; Ameduri, B. Prog. Polym. Sci. 2013, 38, 703−739. (30) Ito, H.; Giese, B.; Engelbrecht, R. Macromolecules 1984, 17, 2204−2205. (31) McElroy, K. T.; Purrington, S. T.; Bumgardner, C. L.; Burgess, J. P. J. Fluorine Chem. 1999, 95, 117−120. (32) Narita, T. Prog. Polym. Sci. 1999, 24, 1095−1148. (33) Aglietto, M.; Passaglia, E.; di Mirabello, L. M.; Botteghi, C.; Paganelli, S.; Matteoli, U.; Menchi, G. Macromol. Chem. Phys. 1995, 196, 2843−2853. (34) Ito, H.; Miller, D. C. J. Polym. Sci., Part A: Polym. Chem. 2004, 42, 1468−1477. (35) Ito, H.; Okazaki, M.; Miller, D. C. J. Polym. Sci., Part A: Polym. Chem. 2004, 42, 1478−1477. (36) Cracowski, J.-M.; Montembault, V.; Odobel, F.; Ameduri, B.; Fontaine, L. J. Polym. Sci., Part A: Polym. Chem 2009, 47, 6116−6123. (37) Meng, Y.; Xu, G.; Song, H.; Xu, Y. Polym. Int. 1998, 45, 389− 394. (38) Hurtgen, M.; Debuigne, A.; Jerome, C.; Detrembleur, C. Macromolecules 2010, 43, 886−894. (39) Hurtgen, M.; Debuigne, A.; Fustin, C.-A.; Jerome, C.; Detrembleur, C. Macromolecules 2011, 44, 4623−4631. 1236
DOI: 10.1021/acsmacrolett.6b00707 ACS Macro Lett. 2016, 5, 1232−1236
