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above approach, the pendant group approach has also been extensively explored for the fabrication ofthermally self-healing polymers. Most of the examples 140-142 are based on the incorporation of furanmoiety as pendant groups (Figure – 1.24a) onto a thermoplastic or a thermoset polymer while a bis- ortrismaleimide (Figure – 1.24b) compound is added as reversible crosslinking agent. Additionally, directpolymerization of furan based methacrylates with other methacrylates using atomic transfer radicalpolymerization to obtain controlled molecular architectures has also been performed 143,144 . In a recentwork, a recyclable furan functionalized polyketone thermoset, crosslinked with bismaleimide waspresented 145 . The reversible gelation as a function of temperature was used as an indicator for DA andrDA reactions demonstrating the thermal reversibility of the system. The recyclability of the system wasproved by grinding a fractured sample and fabricating a new sample from it. The new sample performedas similar as the pristine sample in mechanical tests which led the authors to claim a 100 % healingefficiency in an otherwise different context.Figure – 1.24: Thermoreversible complex architectures made reaction of, a) Hydroxyethylcellulose furoate acetatewith, b) Bismaleimide to form, c) Crosslinked polymer having flexible structure with liquid crystalline properties 141Besides furan/maleimide combination, there are also other compounds like dicyclopentadiene 146-148 and anthracene 149 which have been used recently to fabricate thermally reversible polymers. Theadvantages of dicyclopentadiene is its cyclic nature which provides a favorable s-cis conformation forDiels-Alder reaction and its ability to self-react to form DA adduct rendering the need to use maleimideas a dienophile. For instance, in one example, a biscyclopentadiene end-functionalized PMMA wassynthesized and then crosslinked with a trifunctional pyridinyl dithioformate compound via hetero-DAreaction 150 (Figure – 1.25). Although no healing data in terms of mechanical properties or visual healingwas presented, the so called “bonding” at room temperature in 10 minutes and “debonding” at29
temperature greater than 80 o C in less than 5 minutes of the system was demonstrated by size exclusionchromatography and ultra-violet spectroscopy.Figure – 1.25: Thermoreversible crosslinked Poly(methyl methacrylate) network formation via hetero Diels-Alderreaction 150 .The high temperatures associated with rDA reactions may sometimes generate undesirablebyproducts due to decomposition of the polymer or any other reactant present in the system. Also asignificant emphasis has been put towards the development of room temperature self-healing systems;therefore it is desirable to reduce the required temperature for rDA reaction as low as possible tominimize the need of energy for the healing process and if possible a complete replacement of heatingprocedure itself. In view of this constraint, use of ultrasound as a tool to facilitate rDA reaction has beenproposed recently. In this work, poly(methyl acrylate)s (PMAs) of different molecular weights wereprepared from a Diels-Alder adduct of maleimide with furan containing two polymerization initiators.When subjected to ultrasound at 0 o C, the authors demonstrated the occurrence of rDA with gelpermeation chromatography (GPC), ultra-violet visible spectroscopy and chromophore labeling of theliberated maleimide and furan moieties. However the no rDA reaction was observed for polymers withmolecular weight greater than 60 KDa and lesser than 20 KDa. Similar results were obtained foranalogous polymers that were prepared from a cycloaddition adduct initiators of maleimide withanthracene. Driven by the same constraint, new class self-healing polymer films have been successfullyprepared by capitalizing over room temperature dynamic Diels-Alder chemistry 151 . In this novel work byReutenauer et al, self standing thin films were casted from a mixture of bis(fulvene) andbis(tricyanoethylenecarboxylate) dynamers (Figure – 1.26a). To demonstrate the self-healing ability, thefilm was cut into two pieces and then the two pieces were pressed together with some overlapping. Inless than 10 seconds, the pieces could no longer be separated (Figure – 1.26b). This is in contrast withthe behavior shown by self-healing supramolecular elastomer which showed healing only between two30
Page 1: THESISPRESENTED ATNATIONAL GRADUATE
Page 4 and 5: As the human civilization progress
Page 6 and 7: CHAPTER - 1 SELF-HEALING POLYMERIC
Page 8: 8.1.5 Atomic Force Microscopy …
Page 11 and 12: Synthetic engineering materials in
Page 13 and 14: esponse to a specific external stim
Page 15 and 16: The first work based on this approa
Page 17 and 18: een prepared from urea-formaldehyde
Page 19 and 20: monomer systems. The addition of EN
Page 21 and 22: Figure - 1.10: Self-healing process
Page 23 and 24: was required to reach healing effic
Page 25 and 26: In addition to above works, some ot
Page 27 and 28: that have been identified to be tak
Page 29 and 30: part of the chapter, these material
Page 31 and 32: Figure - 1.17: Self-healing of the
Page 33 and 34: commercialized under tradenames; Nu
Page 35 and 36: joined together at temperature high
Page 37: Inspired by these findings, the fir
Page 41 and 42: Figure - 1.27: Sulfur chemistry bas
Page 43 and 44: A different kind of sulfur chemistr
Page 45 and 46: Figure - 1.29: Dynamic covalent che
Page 47 and 48: cracks. The recovered droplets afte
Page 49 and 50: 23 White, S. R. et al. Autonomic he
Page 51 and 52: 65 Taber, D. F. & Frankowski, K. J.
Page 53 and 54: 107 Kushner, A. M., Vossler, J. D.,
Page 55: 148 Park, J. S., Kim, H. S. & Hahn,
Page 58 and 59: The value of subscripts “n”,
Page 60 and 61: The formation of spherical micelles
Page 62 and 63: the micelle assembly showed the pre
Page 64 and 65: gain onto the electrodes by buildin
Page 66 and 67: The resistance R can be further exp
Page 68 and 69: empty-tower velocity U only depends
Page 70 and 71: This apparent morphological switchi
Page 72 and 73: In a further qualitative analysis,
Page 74 and 75: noteworthy and though its feasibili
Page 76 and 77: Furthermore within this range, lowe
Page 78 and 79: Figure - 2.22: Scanning Electron Mi
Page 80 and 81: While the resistance measurements g
Page 82 and 83: In conclusion, a self-healing membr
Page 84 and 85: 23 Giacomelli, F. C., Riegel, I. C.
Page 86 and 87: micelles enabled the membrane to se
Page 88 and 89:
The second class is represented by
Page 90 and 91:
To avoid the probable clogging of t
Page 92 and 93:
181614SP2 - iNumber of Particles121
Page 94 and 95:
1000900800y = 3E+06xR² = 0,9911y =
Page 96 and 97:
very high value of 1.5 g.l -1 . Thi
Page 98 and 99:
Since the only change in the membra
Page 100 and 101:
100Retention (%)8060400,100,20,40,6
Page 102 and 103:
Figure - 3.18: Scanning Electron Mi
Page 104 and 105:
(Figure - 3.20). A cursory look at
Page 106 and 107:
When compared to poly(styrene) NPs,
Page 108 and 109:
Figure - 3.24: Scanning Electron Mi
Page 110 and 111:
REFERENCES1 Metzler, R. & Klafter,
Page 112 and 113:
46 Bemporad, D., Luttmann, C. & Ess
Page 114 and 115:
In this chapter, preparation of 3D
Page 116 and 117:
obtain complex macromolecular archi
Page 118 and 119:
The polymerization was conducted at
Page 120 and 121:
proceeds, lesser monomer is availab
Page 122 and 123:
mg/ml),the micelles’ hydrodynamic
Page 124 and 125:
Figure - 4.15: The monolayer and mu
Page 126 and 127:
monolayer of micelles and topmost l
Page 128 and 129:
The presence of the dispersed micel
Page 130 and 131:
Heating the multilayer micelle asse
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stable zipping of the micelles. Mul
Page 134 and 135:
24 Moad, G., Rizzardo, E. & Thang,
Page 136 and 137:
The concept of nano-gel based self-
Page 138 and 139:
Figure - 5.4: Size distribution of
Page 140 and 141:
In a typical process, the two compo
Page 142 and 143:
Figure - 5.10: 1HNMR spectra obtain
Page 144 and 145:
The 1 HNMR spectrum obtained for th
Page 146 and 147:
REFERENCES1 White, S. R. et al. Aut
Page 148 and 149:
healing ability shown by the membra
Page 150 and 151:
7. PERSPECTIVESBeing the first such
Page 153 and 154:
8. MATERIALS & METHODSThis chapter
Page 155 and 156:
8.1.3 PEG Filtration MeasurementsTh
Page 157 and 158:
addition of TEOS due to formation o
Page 159 and 160:
solution was ultrasonicated for 15
Page 161 and 162:
Triethylamine (TEA) (Sigma-Aldrich
Page 163 and 164:
To prepare the monolayer assembly o
Page 165 and 166:
was added followed by addition of 0
Page 168 and 169:
ELABORATION OF SELF-HEALING POLYMER
Page 170 and 171:
ELABORATION DES MEMBRANES POLYMERES
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4(%3)3 - Ecole nationale supÃ©rieure de chimie de Montpellier

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