27 lines
29 KiB
JSON
27 lines
29 KiB
JSON
[
|
||
{
|
||
"id": 1,
|
||
"chunk": "# Thiol-Epoxy Polymerization via an AB Monomer: Synthetic Access to High Molecular Weight Poly( $\\beta$ -hydroxythio-ether)s \n\nSelmar Binder, Ikhlas Gadwal, Andreas Bielmann, Anzar Khan \n\nDepartment of Materials, ETH-Z€urich, 8093 Z€urich, Switzerland Correspondence to: A. Khan (E-mail: anzar.khan $@$ mat.ethz.ch) \n\nReceived 11 March 2014; accepted 8 April 2014; published online 00 Month 2014 \nDOI: 10.1002/pola.27212 \n\nABSTRACT: A synthetic route is developed for the preparation of an AB-type of monomer carrying an epoxy and a thiol group. Base-catalyzed thiol-epoxy polymerization of this monomer gave rise to poly $\\beta$ -hydroxythio-ether)s. A systematic variation in the reaction conditions suggested that tetrabutyl ammonium fluoride, lithium hydroxide, and 1,8-diazabicycloundecene (DBU) were good polymerization catalysts. Triethylamine, in contrast, required higher temperatures and excess amounts to yield polymers. THF and water could be used as polymerization mediums. However, the best results were obtained in bulk conditions. This required the use of a mechanical stirrer due to the high viscosity of the polymerization mixture. The polymers obtained from the AB monomer route exhibited significantly higher molecular weights $(M_{\\mathrm{w}}=47,700,$ $M_{\\mathrm{n}}=23,200~\\mathrm{g/mol})$ than the materials prepared from an AA/BB type of the monomer system $(M_{\\mathrm{w}}=10,000$ , $M_{\\mathrm{n}}{=}5400~\\mathrm{g/mol)}$ . The prepared reactive polymers could be transformed into a fluorescent or a cationic structure through postpolymerization modification of the reactive hydroxyl sites present along the polymer backbone. $\\circledcirc$ 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 00, 000–000 \n\nKEYWORDS: addition polymerization; functionalization of polymers; thiol-epoxy reaction; polyelectrolytes; click polymerization \n\nINTRODUCTION Robust, efficient, and orthogonal (REO) approaches to macromolecular synthesis have revolutionized the manner in which functional soft materials are being prepared.1–11 Inspired by this philosophy, recently, efficient, and robust coupling reaction between a thiol and an epoxy unit11–14 was demonstrated to give access to a new family of reactive polymers referred to as poly( $\\displaystyle{\\beta}$ -hydroxythioether)s.11(c) The polymerization process is shown to occur in the presence of moisture and air from commercially available and inexpensive monomers and the resulting polymers could be converted into functionalized structures in a single postpolymerization step. The synthetic ease, commercial availability of the building blocks, modular nature of the process, and avenue for functionalization suggested that this new family of polymers could find wide ranging applications. \n\nIn the previous design,11(c) however, synthesis of poly( $\\mathrm{\\Delta}\\cdot\\mathrm{\\Delta}\\beta$ - hydroxythio-ether)s was accomplished through a polyaddition reaction between AA and BB types of monomers. The advantage associated with this approach lies in the commercial availability of a variety of di-thiol and di-epoxide molecules. The disadvantage, however, is that the attainable degree of polymerization in an AA/BB system is highly sensitive to the functional group stoichiometry.15 A failure to meet the 1:1 functional group balance prevents the formation of high molecular weight polymers as the excess functionality can act as a chain terminator. To satisfy the stringent requirement of stoichiometric balance, the monomers utilized should be of very high purity and should be weighed, measured, and transferred into the reaction vessel with utmost precision. In contrast, utilization of an AB system for the polymerization reaction alleviates these issues due to an inherent balance of the two reactive groups in a single molecule. Placing two mutually reactive functionalities on the same molecule, however, may not be a straightforward affair. This requires careful development of a synthetic strategy that involves orthogonal organic transformations of the functional groups. Nonetheless, this task is worth undertaking as, in principal, high degrees of polymerization could be achieved using an AB monomer system. Therefore, in this work, we discuss the synthesis of an AB type of monomer for the synthesis of relatively high molecular weight poly( $\\beta$ -hydroxythio-ether)s through the thiolepoxy polyaddition reaction (Scheme 1). Furthermore, we demonstrate that these polymers represent a general reactive scaffold that can be transformed into a desired functionalized structure. \n\n \nSCHEME 1 Synthesis and functionalization of poly $\\boldsymbol{{\\mathrm{\\cdot}}}\\beta$ -hydroxythio-ether)s through an AB monomer. \n\n \nFIGURE 1 ${}^{1}\\mathsf{H N M R}$ of compounds 1 (bottom), 2 (middle), and AB monomer 3 (top) in $\\mathsf{C D C l}_{3}$ . Tetramethylsilane (TMS) was used as an internal standard. \n\n \nFIGURE 2 Crude GPC traces showing evolution of molecular weight in the thiol-epoxy polyaddition reaction as a function of polymerization time.",
|
||
"category": " Abstract"
|
||
},
|
||
{
|
||
"id": 2,
|
||
"chunk": "# RESULTS AND DISCUSSION \n\nIn the present context, an AB monomer is comprised of a molecule carrying a free thiol and an epoxide unit (Scheme 1). Thiols are excellent nucleophiles under basic conditions and epoxides are sensitive to an acidic environment. Therefore, synthesis of an AB monomer suitable for the thiol-epoxy polymerization may be problematic to prepare under acidic or basic conditions. Hence, we referred to free radical chemistry (chemically neutral conditions) for the synthesis of such a bifunctional monomer. For this, a thiol group of bis-mercaptoethyl ether, 1, was allowed to react with an alkene functionality of allyl glycidyl ether, 2, under ambient light and aerobic conditions at room temperature (Scheme 1). It is known that exposure of alkenes to air results in the formation of peroxides that can catalyze the addition of thiols to the alkene functionality.16 This process is self-catalytic in nature, and known to be accelerated by light. This furnished the AB monomer 3 carrying the necessary thiol and epoxide functionalities. To confirm the free radical nature of the coupling reaction between precursors 1 and 2, a free radical inhibitor, 2,6-ditert-butyl-4-methylphenol (BHT) was added to the reaction mixture. In this case, no coupling product was observed even after 2 days of reaction time. This suggested that the coupling reaction in between molecules 1 and 2 was free radical in nature. Monomer 3 was purified through a flash column chromatography technique as some degradation of the monomer, presumably due to sensitivity of the epoxide unit, was observed upon its prolonged stay on the silica gel column. Once purified, the monomer could be stored for a few weeks under inert conditions and at low temperatures. The reaction between molecules 1 and 2 to generate monomer 3 could be followed with the help of $^1\\mathrm{H}$ NMR spectroscopy, as olefin resonances at 4.1, 5.2, and 5.9 ppm could no longer be observed upon free radical coupling reaction. Moreover, a new signal could be observed at $1.8~\\mathrm{ppm}$ due to the newly formed methylene group in 3 (designated with $\\mathbf{\\dot{e}}^{\\prime}$ in Fig. 1). The purity of monomer 3 could be verified with the help of elemental analysis, which showed that the theoretical ratio of elements (C, H, O, and S) were in excellent agreement to the experimentally determined values (Supporting Information Fig. S1). \n\nTo establish optimum polymerization conditions, a series of test reactions using freshly prepared monomer was carried out in tetrahydrofuran (THF) (Fig. 2) and the resulting polymerization mixture was precipitated into either diethyl ether or an ethyl acetate/hexane (1:3) mixture (Table 1). It was observed that the polymerization yield was low in diethyl ether and high in ethyl acetate/hexane mixture. The low polymerization yield and relatively high molecular weights observed upon precipitation into diethyl ether indicate polymer fractionation. Therefore, only the results obtained through precipitation into ethyl acetate/hexane mixture are compared. \n\nTABLE 1 Thiol-Epoxy Polymerization of Monomer 3 \n\n\n<html><body><table><tr><td>Entry</td><td>Catalyst</td><td>T (C)</td><td>Time (h)</td><td>Solvent</td><td>Conc. (mM)</td><td>Mn (g/mol)</td><td>Mw (g/mol)</td><td>PDI (Mw/Mn)</td><td>Precip.</td><td>Yield (%)</td></tr><tr><td>1</td><td>TEA</td><td>25</td><td>24</td><td>THF</td><td>398</td><td></td><td></td><td>_</td><td>_</td><td>-</td></tr><tr><td>２</td><td>TEA</td><td>50</td><td>22</td><td>THF</td><td>398</td><td>10,800</td><td>18,000</td><td>1.66</td><td>EA/Hex</td><td>84</td></tr><tr><td>3</td><td>TBAF</td><td>25</td><td>24</td><td>THF</td><td>398</td><td>10,600</td><td>23,600</td><td>2.22</td><td>Ether</td><td>48</td></tr><tr><td>4</td><td>TBAF</td><td>50</td><td>22</td><td>THF</td><td>398</td><td>7,500</td><td>11,700</td><td>1.55</td><td>Ether</td><td>48</td></tr><tr><td>５</td><td> DBU</td><td>25</td><td>22</td><td>THF</td><td>398</td><td>6,200</td><td>10,800</td><td>1.74</td><td>EA/Hex</td><td>78</td></tr><tr><td>6</td><td>LiOH</td><td>25</td><td>24</td><td>THF/H2O</td><td>398</td><td>41,100</td><td>75,900</td><td>1.84</td><td>Ether</td><td>52</td></tr><tr><td>7</td><td>LiOH </td><td>25</td><td>3</td><td>H2O</td><td>398</td><td>13,200</td><td>26,800</td><td>2.03</td><td>Ether</td><td>20</td></tr><tr><td>8</td><td>LiOH</td><td>50</td><td>22</td><td>THF/H2O</td><td>398</td><td>15,900</td><td>28,500</td><td>1.79</td><td>EA/Hex</td><td>60</td></tr><tr><td>９</td><td>TEA</td><td>25</td><td>20</td><td>THF</td><td>792</td><td>一</td><td>一</td><td></td><td></td><td></td></tr><tr><td>10</td><td>TEA</td><td>50</td><td>20</td><td>THF</td><td>792</td><td>9,400</td><td>16,600</td><td>1.76</td><td>EA/Hex</td><td>83</td></tr><tr><td>11</td><td> TBAF</td><td>25</td><td>20</td><td>THF</td><td>792</td><td>9,300</td><td>16,800</td><td>1.80</td><td>EA/Hex</td><td>68</td></tr><tr><td>12</td><td>LiOH</td><td>25</td><td>20</td><td>THF/H2O</td><td>792</td><td>23,100</td><td>46,800</td><td>2.02</td><td>Ether</td><td>72</td></tr><tr><td>13</td><td>LiOH</td><td>25</td><td>3</td><td>H2O</td><td>792</td><td>20,700</td><td>39,500</td><td>1.90</td><td>EA/Hex</td><td>38</td></tr><tr><td>14</td><td>LiOH</td><td>25</td><td>14</td><td>Bulk</td><td>-</td><td>23,200</td><td>47,700</td><td>2.02</td><td>EA/Hex</td><td>99</td></tr><tr><td>15</td><td>LiOH </td><td>25</td><td>24</td><td>Bulk</td><td>-</td><td>24,600</td><td>51,300</td><td>2.08</td><td>EA/Hex</td><td>93</td></tr></table></body></html>\n\n$7\\:\\mathrm{mol\\%}$ of the catalyst was used except in entries 2, 9, and 10 in which the catalyst was used as a co-solvent (1:1 vol/vol); molecular weight determination was done through gel permeation chromatography (GPC) using polystyrene standards; precipitation was carried out either in diethyl ether or a $25\\%$ ethyl acetate (EA) in hexane (Hex) solvent mixture. \n\n \nFIGURE 3 GPC traces of purified polymer 4 (solid line $\\c=$ entry 15, dash line $\\O=$ entry 14, dash dot line $\\O=$ entry 10, and small dash line $\\O=$ entry 11 in Table 1). \n\nInitially, triethylamine (TEA) was used as a catalyst due to its mild nature. However, no polymer formation was observed in this reaction at room temperature. Therefore, the reaction temperature was increased to $50~^{\\circ}\\mathrm{C}$ and TEA was used as a co-solvent. These changes resulted in the formation of polymer 4. However, the molecular weight of the generated polymer remained low $(M_{\\mathrm{w}}=18,000$ , $M_{\\mathrm{n}}=10{,}800$ $\\mathrm{g/mol}\\mathrm{\\Delta}$ . The polymerization catalyst was then changed to tetrabutylammonium fluoride (TBAF). TBAF is soluble in a variety of organic solvents as well as water, and known to be a good catalyst for the thiol-epoxy reaction.11(e),17 In the presence of TBAF, polymer formation could be observed at room temperature. The molecular weight of the polymer, however, still remained low $(M_{\\mathrm{w}}=16,800$ , $M_{\\mathrm{n}}{=}9300~\\mathrm{g/mol})$ . Increasing the reaction temperature did not alter the outcome of the polymerization reaction. Therefore, lithium hydroxide was used as the polymerization catalyst. This catalyst has been used with significant success for the thiol-epoxy coupling reaction in small molecular18 as well as polymeric11(a– c) systems. This reaction produced a relatively higher molecular weight polymer $(M_{\\mathrm{w}}=28,500$ , $M_{\\mathrm{n}}{=}15{,}900\\mathrm{g/mol})$ . Encouraged by these results, bulk polymerizations were carried out using LiOH as the polymerization catalyst. This, however, required the use of a mechanical stirrer due to the high viscosity of the polymerization mixture. These polymerizations produced high molecular weight polymers $(M_{\\mathrm{w}}=47,700$ , $M_{\\mathrm{n}}{}=23,200~\\mathrm{g/mol})$ with quantitative polymerization yields in a highly reproducible fashion. In general, the molecular weights produced via polymerization of an AB monomer (Fig. 3) were found to be significantly higher (Table 1) than the molar mass of the polymers obtained through an AA/BB route.11(c) \n\nIn $^1\\mathrm{H}$ NMR spectroscopy, upon polymerization, the epoxide proton resonance (designated $\\mathrm{^{\\prime}g^{\\prime}}$ in Fig. 1) at $3.2~\\mathrm{ppm}$ shifted to about 3.9 ppm (designated ‘e’ in Fig. 4) due to the opening of the epoxide ring and subsequent formation of the hydroxyl group. The hydroxyl group formation was also evident through IR spectroscopy in which a broad band could be observed at $3450~\\mathrm{cm}^{-1}$ (Fig. 5). MALDI-TOF mass spectrometry measurements showed an expected peak interval of 252 Da corresponding to the molecular weight of the repeat unit in polymer 4 (Fig. 6). \n\n \nFIGURE 4 $^1\\mathsf{H}$ NMR of polymers 4 (bottom) and 5 (top) in $\\mathsf{C D C l}_{3}$ . TMS was used as an internal standard. \n\n \nFIGURE 5 IR spectra of polymers 4 (top) and 5 (bottom). \n\nThe hydroxyl groups of polymer 4 (Entry 6, Table 1) could be used as an anchor point to install functional groups to the polymer backbone. To demonstrate this, a fluorescent moiety, pyrene, could be attached to the polymer chain through an esterification reaction. The postfunctionalization conversion of the hydroxyl to ester group was determined to be $85\\mathrm{-}90\\%$ by comparing the area integration of signals located at 3.9 (precursor polymer 4) and $5.1\\ \\mathrm{ppm}$ (functionalized structure 5) (Fig. 4). In the IR spectra, a decrease in the intensity of the broad hydroxyl band at $3450~\\mathrm{cm}^{-1}$ and the appearance of an ester-carbonyl signal at $1710~\\mathrm{{cm}}^{-1}$ (Fig. 5) were observed after the functionalization reaction. These data supported the structure determined by the $^1\\mathrm{H}$ NMR spectroscopy. UV–vis spectroscopy further established the presence of pyrene units in polymer 5 as this polymer exhibited absorption bands in the range of $225\\substack{-375}\\ \\mathrm{nm}$ (Fig. 7). Due to functionalization with a pyrene chromophore, polymer 5 exhibited fluorescence emission properties upon excitation at $347\\ \\mathrm{nm}$ (Fig. 8). The fluorescence emission spectrum of polymer 5 was comprised well-defined bands at 376, 397, and $424\\ \\mathrm{nm}$ belonging to the pyrene monomer, and a broad and structure-less band centered at $483\\ \\mathrm{nm}$ belonging to the pyrene excimer. Thermal analysis indicated that the polymers were stable up to $290{-}295^{\\circ}\\mathrm{C}$ . A significant difference was observed in the glass transition property of the polymers. Polymer 4 exhibited a $T_{\\mathrm{g}}$ of $-51~^{\\circ}\\mathrm{C}$ (Supporting Information Fig. S2). As expected, substitution with the pyrene group increased the $T_{\\mathrm{g}}$ in polymer 5 to $-33\\ ^{\\circ}\\mathsf{C}$ . MALDI-TOF mass analysis further confirmed the molecular structure of the repeat unit in polymer 5 (Supporting Information Fig. S3). \n\n \nFIGURE 6 MALDI-TOF mass spectra of polymer 4 (entry 15 in Table 1). \n\n \nFIGURE 7 UV–vis spectra of pyrene-functionalized polymer 5 in chloroform. \n\n \nFIGURE 8 Fluorescence emission spectrum of polymer 5 upon excitation at $347~\\mathsf{n m}$ . \n\n \nFIGURE 9 $^1\\mathsf{H}$ NMR of polymers 6 in DMSO- $\\cdot{\\mathsf{d}}_{6}$ (bottom) and ${\\mathsf{D}}_{2}{\\mathsf{O}}$ (top). \n\nTo demonstrate the generality of the reactive scaffold, the secondary hydroxyl groups of polymer 4 (Entry 15, Table 1) were functionalized with the $t$ -butoxycarbonyl (Boc)-protected glycine molecule. A successful functionalization was evident by the appearance of a signal at $5.1\\ \\mathrm{ppm}$ from the proton located adjacent to the newly formed ester group and the proton resonance signal of the Boc unit at $1.4~\\mathrm{ppm}$ (Supporting Information Fig. S4). Finally, the Boc groups could be removed under acidic conditions. This gave rise to a polymer carrying a primary ammonium site alongside the polymer backbone. In deuterated dimethylsulfoxide $\\left(\\mathrm{DMSO-}d_{6}\\right)$ ), the ammonium signal could be observed at 8.4 ppm. This functionalized cationic polymer (6) was completely soluble in water (Fig. 9). Therefore, $^1\\mathrm{H}$ NMR study could also be carried out in deuterated water $\\left(\\mathsf{D}_{2}0\\right)$ , which confirmed that the signal at $8.4~\\mathrm{ppm}$ in DMSO- $\\cdot d_{6}$ belonged to the ammonium group as it could no longer be observed in $\\mathtt{D}_{2}0$ due to a fast exchange with deuterium.",
|
||
"category": " Results and discussion"
|
||
},
|
||
{
|
||
"id": 3,
|
||
"chunk": "# CONCLUSIONS \n\nIn conclusion, a synthetic route is developed for the preparation of an AB type of monomer suitable for thiol-epoxy polymerization. For this, a thiol unit of bis-mercaptoethyl ether was coupled to the alkene functionality of allyl glycidyl ether in a free radical fashion. This afforded the desired monomer carrying the two reactive groups—a thiol and an epoxide— necessary for the thiol-epoxy polymerization reaction. A systematic variation in the reaction conditions suggested that TBAF, LiOH, and DBU were good polymerization catalysts. TEA, on the other hand, required higher temperatures and an excess amount to produce polymers. THF and water could be used as polymerization mediums. The best results, however, were obtained in bulk conditions. This, however, necessitated the use of a mechanical stirrer due to the high viscosity of the polymerization mixture. The synthesized polymers could be converted into a fluorescent or a cationic structure through postpolymerization modification reaction of the hydroxyl units. The functionalized polymers exhibited substituent dependent properties. Most importantly, the molecular weight of the polymers resulting from the present AB monomer route was found to be significantly higher than the molecular weight of the polymers prepared through a previously reported AA/BB approach.",
|
||
"category": " Conclusions"
|
||
},
|
||
{
|
||
"id": 4,
|
||
"chunk": "# ACKNOWLEDGMENTS \n\nFinancial support from SNSF is acknowledged. AK thanks A. D. \nSchl€uter for support.",
|
||
"category": " References"
|
||
},
|
||
{
|
||
"id": 5,
|
||
"chunk": "# REFERENCES AND NOTES \n\n1 For review articles, please see: (a) C. J. Hawker, K. L. Wooley, Science 2005, 309, 1200–1205; (b) C. J. Hawker, V. V. Fokin, M. G. Finn, K. B. Sharpless, Aust. J. Chem. 2007, 60, 381–383; (c) R. K. Iha, K. L. Wooley, A. M. Nystrom, D. J. Burke, M. J. Kade, C. J. Hawker, Chem. Rev. 2009, 109, 5620–5686; (d) M. J. Kade, D. J. Burke, C. J. Hawker, J. Polym. Sci. Part A: Polym. Chem. 2010, 48, 743–750; (e) F. A. Leibfarth, C. J. Hawker, J. Polym. Sci. Part A: Polym. Chem. 2013, 51, 3769–3782; (f) C. E. Hoyle, A. B. Lowe, C. N. Bowman, Chem. Soc. Rev. 2010, 39, 1355– 1387; (g) A. Sanyal, Macromol. Chem. Phys. 2010, 211, 1417– 1425; (h) A. B. Lowe, M. A. Harvison, Aust. J. Chem. 2010, 63, 1251–1266; (i) H. Durmaz, A. Sanyal, G. Hizal, U. Tunca, Polym. Chem. 2012, 3, 825–835; (j) E. B. Maren, M. L. David, Polym. Chem. 2012, 3, 66–80; (k) U. Tunca, Macromol. Rapid Commun. 2013, 34, 38–46; (l) A. S. Goldmann, M. Glassner, A. J. Inglis, C. Barner-Kowollik, Macromol. Rapid Commun. 2013, 34, 810–849; (m) G. Lligadas, J. C. Ronda, M. Galia\u0002, V. Ca\u0003diz, J. Polym. Sci. Part A: Polym. Chem. 2013, 51, 2111–2124; (n) P. J. Roth, C. Boyer, A. B. Lowe, T. P. Davis, Macromol. Rapid Commun. 2011, 32, 1123–1143; (o) J.-F. Lutz, Angew. Chem. Int. Ed. 2007, 46, 1018–1025; (p) (l) Theato, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 6677–6687; (m) K. A. G€unay, P. Theato, H.-A. Klok, J. Polym. Sci. Part A: Polym. Chem. 2013, 51, 1–28. 2 (a) P. Wu, A. K. Feldman, A. K. Nugent, C. J. Hawker, A. Scheel, B. Voit, J. Pyun, J. M. J. Fre\u0003chet, K. B. Sharpless, V. V. Fokin. Angew. Chem. Int. Ed. 2004, 43, 3928–3932; (b) S. Binauld, C. J. Hawker, E. Fleury, E. Drockenmuller, Angew. Chem. Int. Ed. 2009, 48, 6654–6658; (c) K. Takizawa, H. Nulwala, \n\nR. J. Thibault, P. Lowenhielm, K. Yoshinaga, K. L. Wooley, C. J. Hawker, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 2897– 2912; (d) E. D. Pressly, R. J. Amir, C. J. Hawker, J. Polym. Sci. Part A: Polym. Chem. 2011, 49, 814–819; (e) H. Nulwala, K. Takizawa, A. Odukale, A. Khan, R. J. Thibault, B. R. Taft, B. H. Lipshutz, C. J. Hawker Macromolecules 2009, 42, 6068–6074; (f) H. Nulwala, D. J. Burke, A. Khan, A. Serrano, C. J. Hawker, Macromolecules 2010, 43, 5474–5477. \n3 (a) K. Nilles, P. Theato, J. Polym. Sci. Part A: Polym. Chem. 2010, 48, 3683–3692; (b) K. T. Wiss, P. Theato, J. Polym. Sci. Part A: Polym. Chem. 2010, 48, 4758–4767; (c) M. Eberhardt, R. Mruk, R. Zentel, P. Theato, Eur. Polym. J. 2005, 41, 1569–1575. 4 (a) Y.-Z. Wang, X.-X. Deng, L. Li, Z.-L. Li, F.-S. Du, Z.-C. Li, Polym. Chem. 2013,4, 444–448; (b) L. Li, X.-W. Kan, X.-X. Deng, C.-C. Song, F.-S. Du, Z.-C. Li, J. Polym. Sci. Part A: Polym. Chem. 2013, 51, 865–873; (c) X.-X. Deng, L. Li, Z.-L. Li, A. Lv, F.-S. Du, Z.- C. Li, ACS Macro Lett. 2012, 1, 1300–1303; (d) L. Li, A. Lv, X.-X. Deng, F.-S. Du, Z.-C. Li, Chem. Commun. 2013, 49, 8549–8551. 5 (a) H. B. Nulwala, C. N. Tang, B. W. Kail, K. Damodaran, P. Kaur, S. Wickramanayake, W. Shi, D. R. Luebke, Green Chem. 2011, 13, 3345–3349; (b) C. N. Tang, H. B. Nulwala, K. Damodaran, P. Kaur, D. R. Luebke, J. Polym. Sci. Part A: Polym. Chem. 2011, 49, 2024–2032; (c) M. Lartey, M. Gillissen, B. J. Adzima, K. Takizawa, D. R. Luebke, H. B. Nulwala, J. Polym. Sci. Part A: Polym. Chem. 2013, 51, 3359–3364; (d) B. J. Adzima, S. C. Taylor, H. He, D. R. Luebke, K. Matyjaszewski, H. B. Nulwala, Polym. Sci. Part A: Polym. Chem. 2014, 52, 417–423. \n6 (a) J. Han, B. Zhao, A. Tang, Y. Gao, C. Gao, Polym. Chem. 2012, 3, 1918–1925; (b) J. Han, B. Zhao, Y. Gao, A. Tang, C. Gao, Polym. Chem. 2011, 2, 2175–2178; (c) J. Wu, C. Gao, Macromolecules 2010, 43, 7139–7146. \n7 (a) L. Billiet, D. Fournier, F. D. Prez, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 6552–6564; (b) L. Billiet, D. Fournier, F. D. Prez, Polymer 2009, 50, 3877–3886; (c) D. Fournier, F. D. Prez, Macromolecules 2008, 41, 4622–4630; (d) L. T. Nguyen, M. T. Gokmen, F. D. Prez, Polym. Chem. 2013, 4, 5527–5536. 8 (a) A. Saha, S. De, M. C. Stuparu, A. Khan, J. Am. Chem. Soc. 2012, 134, 17291–17297; (b) K. Dan, S. Ghosh, Angew. Chem. Int. Ed. 2013, 52, 7300–7305; (c) M. R. Molla, S. Ghosh, Macromolecules 2012, 45, 8561–8570; (d) A. E. Van der Ende, E. J. Kravitz, E. Harth, J. Am. Chem. Soc. 2008, 130, 8706–8713; (e) A. E. Van der Ende, T. Croce, S. Hamilton, V. Sathiyakumar, E. Harth, Soft Matter 2009, 5, 1417–1425; (f) S. K. Hamilton, E. Harth, ACS Nano 2009, 3, 402–410; (g) S. Ghosh, S. Basu, S. Thayumanavan, Macromolecules 2006, 39, 5595–5597; (h) N. Cengiz, H. Kabadayioglu, R. Sanyal, J. Polym. Sci. Part A: Polym. Chem. 2010, 48, 4737–4746; (i) K. A. McEwan, S. Slavin, E. Tunnah, D. M. Haddleton, Polym. Chem. 2013, 4, 2608–2614; (j) S. Gokhale, Y. Xu, A. Joy, Biomacromolecules 2013, 14, 2489–2493; (k) M. L. Neindre, B. Magny, R. Nicola€y, Polym. Chem. 2013, 4, 5577–5584; (l) Y. Li, H. T. T. Duong, M. W. Jones, J. S. Basuki, J. Hu, C. Boyer, T. P. Davis, ACS Macro Lett. 2013, 2, 912–917; (m) J. Liu, H. Duong, M. R. Whittaker, T. P. Davis, C. Boyer, Macromol. Rapid Commun. 2012, 33, 760–766; (n) F. S. Gungor, B. Kiskan, React. Funct. Polym. 2014, 75, 51–55. \n9 For preparation of linear polymers through alkyne-azide coupling reaction, please see: (a) D. D. Dı\u0003az, S. Punna, P. Holzer, A. K. Mcpherson, K. B. Sharpless, V. V. Fokin, M. G. Finn, J. Polym. Sci. Part A: Polym. Chem. 2004, 42, 4392–4403; (b) A. Qin, C. K. W. Jim, W. Lu, J. W. Y. Lam, M. H€aussler, Y. Dong, H. H. Y. Sung, I. D. Williams, G. K. L. Wong, B. Z. Tang Macromolecules, 2007, 40, 2308–2317; (c) S. Binauld, D. Damiron, T. Hamaide, J.-P. Pascault, E. Fleury, E. Drockenmuller, Chem. Commun. 2008, 35, 4138–4140; (d) A. Qin, J. W. Y. Lam, L. Tang, C. K. W. Jim, H. Zhao, J. Sun, B. Z. Tang, Macromolecules 2009, 42, 1421–1424; (e) S. Binauld, E. Fleury, E. Drockenmuller, J. Polym. Sci. Part A: Polym. Chem. 2010, 48, 2470–2476; (f) C. Besset, S. Binauld, M. Ibert, P. Fuertes, J.-P. Pascault, E. Fleury, J. Bernard, E. Drockenmuller, Macromolecules 2010, 43, 17–19; (g) A. Qin, J. W. Y. Lam, B. Z. Tang, Macromolecules 2010, 43, 8693–8702; (h) A. Qin, J. W. Y. Lam, B. Z. Tang, Chem. Soc. Rev. 2010, 39, 2522–2544; (i) H. Li, J. Wang, J. Z. Sun, R. Hu, A. Qin, B. Z. Tang, Polym. Chem. 2012, 3, 1075–1083; (j) J. Wang, J. Mei, R. Hu, J. Z. Sun, A. Qin, B. Z. Tang, J. Am. Chem. Soc. 2012, 134, 9956–9966; (k) J. Han, D. Zhu, C. Gao, Polym. Chem. 2013, 4, 542–549. \n10 For linear polymer synthesis through thiol-ene reaction, please see; (a) H. Mutlu, A. N. Parvulescu, P. C. A. Bruijnincx, B. M. Weckhuysen, M. A. R. Meijer, Macromolecules 2012, 45, 1866–1878; (b) C. Lluch, J. C. Ronda, M. Gali\u0002a, G. Lligadas, V. C\u0003adiz, Biomacromolecules 2010, 11, 1646–1653; (c) O. Tu€r€unc¸, L. M. Espinosa, M. A. R. Meier, Macromol. Rapid Commun. 2011, 32, 1357–1361; (d) J. W. Robinson, H. Schlaad, Chem. Commun. 2012, 48, 7835–7837; (e) J. Vandenbergh, K. Ranieri, T. Junkers, Macromol. Chem. Phys. 2012, 213, 2611–2617; (f) F. Deubel, V. Bretzler, R. Holzner, T. Helbich, O. Nuyken, B. Rieger, R. Jordan, Macromol. Rapid Commun. 2013, 34, 1020– 1025; (g) O. Berg, T. Dispinar, B. Hommez, F. E. D. Prez, Eur. Polym. J. 2013, 49, 804–812; (h) K. Dan, S. Ghosh, Polym. Chem. 2014. doi:10.1039/C4PY00078A. \n11 (a) S. De, A. Khan, Chem. Commun. 2012, 48, 3130–3132; (b) S. De, C. Stelzer, A. Khan, Polym. Chem. 2012, 3, 2342–2345; (c) A. Bra€ndle, A. Khan, Polym. Chem. 2012, 3, 3224–3227; (d) I. Gadwal, A. Khan, Polym Chem. 2013, 4, 2440–2444; (e) N. Cengiz, J. Rao, A. Sanyal, A. Khan, Chem. Commun. 2013, 49, 11191–11193; (f) I. Gadwal, J. Rao, J. Baettig, A. Khan, Macromolecules 2014, 47, 35–40; (g) S. P. Li, J. Han, C. Gao, Polym. Chem. 2013, 4, 1774–1787; (h) S. Li, C. Gao, Polym. Chem. 2013, 16, 4450–4460; (i) J. S. Basuki, L. Esser, H. T. T. Duong, Q. Zhang, P. Wilson, M. R. Whittaker, D. M. Haddleton, C. Boyer, T. P. Davis, Chem. Sci. 2014, 5, 715–726. \n12 For application of thiol/epoxy chemistry on surfaces, see: (a) R. Iwata, R. Satoh, Y. Iwasaki, K. Akiyoshi, Colloid and Surface B: Biointerfaces 2008, 62, 288–298; (b) S. B. Rahane, R. M. Hensarling, B. J. Sparks, C. M. Stafford, D. L. Patton, J. Mater. Chem. 2012, 22, 932–943. \n13 For application of thiol/epoxy chemistry for nanoparticle functionalization, see: X. J. Song, J. Hu, C. C. Wang, Colloid Surf. A: Physicochem. Eng. Aspects 2011, 380, 250–256. \n14 For application of thiol/epoxy chemistry for network synthesis, see reference 11e and; (a) J. A. Carioscia, J. W. Stansbury, C. N. Bowman, Polymer 2007, 48, 1526–1532; (b) Y. Jian, Y. He, Y. Sun, H. Yang, W. Yang, J. Nie, J. Mater. Chem. 2013, 1, 4481–4489; (c) M. Pepels, I. Filot, B. Kluperman, H. Goossens, Polym. Chem. 2013, 4, 4955–4965. \n15 (a) W. H. Carothers, Chem. Rev. 1931, 8, 353–426; (b) G. Odian, Principles of Polymerization, Wiley: New York, 1991. 16 Please see page 388 of the following review article for more details: F. R. Mayo, C. Walling, Chem. Rev. 1940, 27, 351–412. 17 D. Albanese, D. Landini, M. Penso, Synthesis-Stuttgart 1994, 34–36. \n18 N. Azizi, A. Khajeh-Amiri, H. Ghafuri, M. Bolourtchian, Phosphorous Sulfur Silicon 2010, 185, 1550–1557.",
|
||
"category": " References"
|
||
}
|
||
] |