Читать книгу Extrinsic and Intrinsic Approaches to Self-Healing Polymers and Polymer Composites - Ming Qiu Zhang - Страница 4

1 Chapter 1Figure 1.1 Cohesive failures beside plated through holes on copper clad lami...Scheme 1.1 Flow chart of the key stages for thermosetting composite repair....Figure 1.2 Typical repair processes of thermosetting composites represented ...Scheme 1.2 Fusion bonding techniques.Figure 1.3 Blood clotting in an injured vessel.Figure 1.4 Number of research papers on self‐healing polymers and polymer co...Figure 1.5 Connectivity transition difference for the reversible addition (t...Scheme 1.3 Thermally reversible cross‐linking based on Diels–Alder reaction....Figure 1.6 Cross‐linked polymers constructed with dynamic‐covalent boronic e...Scheme 1.4 Strategy for constructing a dynamic hydrogel with an environmenta...Figure 1.7 (a) Scheme illustrating the welding of two pieces of epoxy resin ...Figure 1.8 (a) Chemical structure of the cross‐linked polyurethane (P1). (b)...Figure 1.9 Chemical structure of a PDMS functionalized with 2,6‐pyridinedica...Figure 1.10 (a) Chemical structure of PU‐b‐P(D‐r‐U)‐b‐PU and (b) its microph...Figure 1.11 Schematic diagram of repair concept for polymer matrix composite...Figure 1.12 Vascular hierarchy. (a) 1D straight channels; (b) 2D segregated ...Figure 1.13 Typical extrinsic self‐healing systems based on microcapsules. (...Figure 1.14 Schematic drawing of the formation of microcapsules by in‐situ p...Scheme 1.5 Ring‐opening metathesis polymerization of DCPD.Scheme 1.6 Schematic illustration of polycondensation between HOPDMS and PDE...Figure 1.15 Performance map of self‐healing structural composites. Maximum h...Figure 1.16 Schematic drawing of a cross‐linked polyurethane containing a re...Figure 1.17 Cartoon depicting the ultrasound‐induced mechanochemical scissio...Figure 1.18 Schematic drawing of the mechanochemically initiated reversible ...

2 Chapter 2Figure 2.1 Schematic drawing of a self‐healing epoxy specimen with embedded ...Scheme 2.1 Chemical structure of PETMP.Scheme 2.2 Reaction schemes of melamine‐formaldehyde resins. (a) Formation o...Figure 2.2 DSC heating traces of (a) epoxy (DTP)/PETMP/BDMA = 10.9/8.7/1, (b...Figure 2.3 Effects of storage time and temperature on stability of PMF‐walle...Figure 2.4 Micro‐Raman spectra of (a) cured epoxy, (b) a raw DTP drop on cur...Figure 2.5 Effects of storage time and temperature on stability of PMF‐walle...Figure 2.6 (a) Expansibility and advantages of thermoplastic tubing in const...Figure 2.7 Optical microscopy photo taken from a self‐healing TDCB specimen,...Figure 2.8 Typical load–displacement curves recorded during TDCB tests. The ...Figure 2.9 Influence of capsule concentration on fracture toughness and heal...Figure 2.10 Time dependence of healing efficiency at different temperatures....Scheme 2.3 Reactions between epoxide and mercaptan catalyzed by tertiary ami...Figure 2.11 Influence of species and content of catalyst on healing efficien...Figure 2.12 Influence of combinations of epoxy and mercaptan on healing effi...Figure 2.13 Scanning electronic microscopy images of healed cracks near the ...Figure 2.14 Time dependences of fracture toughness (•) developed in healed s...Figure 2.15 Crack length vs. fatigue cycle of (a) neat epoxy specimen, (b) m...Figure 2.16 Crack length vs. fatigue cycles of (a) control specimen and (b) ...Figure 2.17 Crack length vs. fatigue cycles of (a) control specimen and (b) ...Figure 2.18 Healing efficiency of self‐healing specimens as a function of st...Figure 2.19 Crack length vs. fatigue cycles of self‐healing specimens. The a...Figure 2.20 Healing efficiency of self‐healing specimens with a rest period ...Figure 2.21 Healing efficiency of self‐healing specimens with a rest period ...Figure 2.22 Through‐scan mode ultrasonic images of the impacted self‐healing...Figure 2.23 SEM micrographs of the fractured surfaces of the self‐healing la...Figure 2.24 Experimental results of the orthographic factorial design.Figure 2.25 Non‐isothermal DSC scanning curves of the mixture of 100 parts D...Figure 2.26 Non‐isothermal DSC scanning curves of the mixture of 100 parts D...Figure 2.27 (a) Load–displacement curves and (b) flexural strengths of the c...Figure 2.28 Typical load–displacement curves of the composite laminates with...Figure 2.29 (a) Typical load–displacement curves recorded during indentation...Figure 2.30 (a) Sealed PP tubes containing the mixture of epoxy monomer DTHP...Figure 2.31 Typical fluorescence microscopy images (using an Axio Oberver Z1...Figure 2.32 Effect of (a) tube spacing and (b) foaming agent content on flex...Figure 2.33 Photos of the back surface of the composite laminates with the h...Figure 2.34 Fluorescent microscopy photos of the back face of the composite ...Figure 2.35 (a) Effect of healing time on flexural strength and healing effi...Figure 2.36 Through‐scan mode ultrasonic images of the indentation damaged c...Figure 2.37 Effect of room temperature storage time on flexural strength and...

3 Chapter 3Scheme 3.1 Curing of epoxy in the presence of (C₂H₅)₂O·BF₃.Figure 3.1 Design of the self‐healing PS.Scheme 3.2 Molecular structures of epoxy resins (EPON 828 and DTP), polymeri...Figure 3.2 Scanning electron microscopy photos of DTP‐loaded microcapsules [...Figure 3.3 Fourier transform infrared spectra of EPON 828, EPON 828‐loaded m...Figure 3.4 Scanning electron microscopy photos of DTP‐containing microcapsul...Figure 3.5 Size distribution of DTP‐containing microcapsules. Preparation co...Figure 3.6 Influence of different levels of the five factors (see Table 3.1)...Figure 3.7 Ultraviolet irradiation time dependence of microcapsule yield ini...Scheme 3.3 Photodecomposition of the initiators.Figure 3.8 Schematic drawing of (a) cross‐section of a piece of sisal leaf, ...Figure 3.9 Infiltration time dependence of the loading of (C₂H₅)₂O·BF₃ on di...Figure 3.10 Morphologies of (a) as‐received carbon black, (b) (C₂H₅)₂O·BF₃‐l...Figure 3.11 Schematic drawing of the proposed route for preparing hollow mic...Figure 3.12 Scanning electron microscopy micrographs of (a) hollow microcaps...Figure 3.13 Yields of hollow microcapsules as a function of UV irradiation t...Figure 3.14 Fourier transform infrared spectra of hollow microcapsules.Figure 3.15 Loading rate of (C₂H₅)₂O·BF₃ in hollow microcapsules as a functi...Figure 3.16 In‐situ FTIR spectra tracking the reaction between epoxy and gro...Figure 3.17 (a, b) Dependences of healing efficiency of the self‐healing epo...Figure 3.18 Influence of content of the healing agent on mechanical properti...Figure 3.19 (a) Scanning electron microscopy image in conjunction with (b) E...Figure 3.20 Time dependence of healing efficiency of the self‐healing epoxy ...Figure 3.21 (a, b) Dependence of healing efficiency of the self‐healing epox...Figure 3.22 Dependences of impact strength of healed self‐healing epoxy comp...Figure 3.23 Dependence of healing efficiency of the self‐healing epoxy compo...Figure 3.24 Scanning electron microscopy micrographs of fractured surfaces o...Figure 3.25 Influence of content of (C₂H₅)₂O·BF₃‐loaded capsules on (a) tens...Figure 3.26 (a) Micrograph of hollow silica walled microcapsules, (b) high m...Figure 3.27 Time dependence of temperature of epoxy cured by ethanol solutio...Scheme 3.4 Mechanism of the reaction between SbF₅·HOC₂H₅ and epoxy.Figure 3.28 (a) Infrared absorption of epoxide groups as a function of time ...Figure 3.29 (a) Scanning electron microscopy image of the impact fracture su...Figure 3.30 Healing efficiency versus healing time of self‐healing specimens...Figure 3.31 (a) Crack length versus fatigue cycle of (1) neat epoxy, (2) con...Figure 3.32 Effect of storage time in ambient air on healing efficiency of t...Figure 3.33 Temperature of crack tip of self‐healing specimen as a function ...Scheme 3.5 The reaction mechanism involved in TfOH‐epoxy cure.Figure 3.34 (a) Time dependence of temperature of epoxy cured by different d...Figure 3.35 Temperature dependence of tan δ of (a) unfilled epoxy and (...Figure 3.36 Healing efficiency versus room temperature healing time of self‐...Figure 3.37 (a) Crack length versus fatigue cycle of (1) neat epoxy, (2) con...Figure 3.38 Dependence of fatigue life extension on time of storage in ambie...Figure 3.39 Influence of thermal exposure of self‐healing epoxy composite sp...Figure 3.40 (a) Time‐dependent rheological behaviors of IBH/NaBH₄/GMA mixtur...Scheme 3.6 Redox cationic polymerization of GMA.Figure 3.41 (a) Dependence of healing efficiency of PS on content of pre‐emb...Figure 3.42 (a) Fourier transform infrared spectra of GMA, IBH, PMF, and IBH...Figure 3.43 Dependences of impact strength and healing efficiency of authent...Figure 3.44 (a) Scanning electron microscopy micrograph of the fracture surf...

4 Chapter 4Scheme 4.1 Structural scheme of the latent curing agent CuBr₂(2‐MeIm)₄.Figure 4.1 Schematic drawing of the principle of self‐healing epoxy material...Figure 4.2 Scanning electronic microscopy (SEM) micrograph of urea‐formaldeh...Figure 4.3 FTIR spectra of bisphenol‐A epoxy, urea‐formaldehyde encapsulated...Figure 4.4 Pyrolytic behaviors of bisphenol‐A epoxy, urea‐formaldehyde encap...Figure 4.5 FTIR spectra of 2‐MeIm and CuBr₂(2‐MeIm)₄.Scheme 4.2 Mechanism of the curing reaction between epoxy resin and the comp...Figure 4.6 Temperature dependence of conversion of curing reaction of epoxy ...Figure 4.7 Influence of the content of epoxy‐loaded microcapsules on the ten...Figure 4.8 Influence of (a) content of latent hardener and (b) content of ep...Figure 4.9 SEM micrographs of cured CuBr₂(2‐MeIm)₄‐epoxy system. Content of ...Figure 4.10 Influence of (a) content of latent hardener and (b) content of e...Figure 4.11 SEM micrographs of the fractured surfaces of the self‐healing ep...Figure 4.12 Schematic drawing of (a) the cross‐section of the laminates and ...Figure 4.13 Typical tensile stress–strain curves of the laminates with diffe...Figure 4.14 Typical load (P)–crack opening displacement (δ) curves of t...Figure 4.15 SEM micrographs of (a, b) the fractured surfaces of the self‐hea...Figure 4.16 Interlaminar fracture toughness of the laminates, G_IC, as a func...Figure 4.17 FTIR spectra of the fractured surface of (1) the laminates witho...Figure 4.18 Time dependence of weight of epoxy‐loaded microcapsules measured...Figure 4.19 Temperature dependence of storage modulus, E', and loss fact...Figure 4.20 Time dependence of storage modulus, E', of (a) unfilled epox...Figure 4.21 SEM micrographs of the fractured surfaces of the laminates conta...Figure 4.22 Flowchart of the damage healing procedures and CAI tests.Figure 4.23 Photographs showing the impact damage zones on the woven glass f...Figure 4.24 (a) Residual compressive strength and (b) normalized residual co...Figure 4.25 Influence of impact strength on residual compressive strength of...Figure 4.26 Influence of impact energy on the healing efficiency of CAI spec...Figure 4.27 T‐scan ultrasonic images of the impacted repairable composite la...Figure 4.28 SEM side views of (a) indented composite laminates and (b) inden...Figure 4.29 Influence of lateral pressure on σ^Healed of the composite l...Figure 4.30 Photographs of (a, b) composite laminates that were impacted at ...Figure 4.31 Influence of size of the microcapsules containing epoxy on heali...

5 Chapter 5Scheme 5.1 Chemical structure of GMA.Figure 5.1 Optical microscopic images of GMA‐loaded microcapsules prepared a...Figure 5.2 FTIR spectrum of PMF‐walled microcapsules containing GMA in compa...Figure 5.3 DSC heating traces of GMA/DETA and ground GMA‐loaded microcapsule...Figure 5.4 Thermogravimetric analysis (TGA) and differential thermogravimetr...Figure 5.5 Typical load–displacement curves recorded during TDCB tests. The ...Figure 5.6 FTIR spectra of epoxy resins cured at different DETA/epoxy ratios...Figure 5.7 Effect of content of GMA‐loaded microcapsules on healing efficien...Scheme 5.2 Schematic drawing of crack healing in epoxy composite containing ...Figure 5.8 Effect of healing temperature on healing efficiency at a constant...Figure 5.9 SEM micrographs of the fractured surface of (a) virgin self‐heali...Scheme 5.3 Schematic drawing of crack healing in epoxy composite containing ...Figure 5.10 Time dependences of healing efficiency in comparison with that o...Figure 5.11 Effect of DETA to epoxy ratio on molecular weight between cross‐...Scheme 5.4 Schematic drawing of crack repair by living copolymerization of G...Figure 5.12 Profile of a multilayered microcapsule.Scheme 5.5 Mechanism for ATRP.Figure 5.13 ¹H‐NMR spectrum of resultant PMMA‐Br initiated with 2‐EBiB/CuBr/...Figure 5.14 Characteristics of living polymerization of MMA. (a) ln([M]₀/[M]...Figure 5.15 (a) GPC curves of PMMA before and after chain extension reaction...Figure 5.16 (a) Healing efficiency of PMMA composites containing 15 wt% GMA‐...Figure 5.17 SEM micrographs of fractured surfaces of PMMA composites contain...Figure 5.18 In‐situ confocal Raman microscopy observation [25]. (a) The typi...Figure 5.19 Healing effect of PMMA composites with styrene‐ and styrene/epox...Figure 5.20 Schematic drawing of the route for preparing the multilayered mi...Figure 5.21 3D distribution of the GMA‐loaded multilayered microcapsules in ...Figure 5.22 Time dependence of healing efficiency of the thermally molded se...Figure 5.23 Healing efficiencies of the thermally molded self‐healing PS com...Figure 5.24 Healing efficiencies of the thermally molded self‐healing PS com...Figure 5.25 Effect of the content of the GMA‐loaded multilayered microcapsul...Figure 5.26 (a) Raman spectrum collected from the re‐fractured surface of a ...Figure 5.27 Thermal decomposition temperatures at 1% weight loss of melamine...Figure 5.28 SEM images of (a, c, e) styrene‐loaded microcapsules and (b, d, ...Figure 5.29 FTIR spectra of (a) styrene‐ and (b) BPO‐loaded microcapsules in...Figure 5.30 DSC heating curves of the polymerization of styrene initiated wi...Figure 5.31 Healing efficiency of self‐healing epoxy composites containing s...Figure 5.32 Healing efficiency of control unfilled epoxy specimens that were...

6 Chapter 6Scheme 6.1 Molecular structure of DGFA.Scheme 6.2 (a) Molecular structure of cured DGFA and (b) schematic drawing h...Scheme 6.3 Molecular structure of FGE.Scheme 6.4 Molecular structure of cured FGE.Scheme 6.5 DGFA synthesized by a two‐step route.Figure 6.1 FTIR spectra of (a) raw DGFA and (b) its purified version.Figure 6.2 ¹H‐NMR spectrum of DGFA.Figure 6.3 ¹³C‐NMR spectrum of DGFA.Figure 6.4 DSC heating traces of the mixture of DGFA and MHHPA at stoichiome...Scheme 6.6 DA and retro‐DA reactions between DGFA and DPMBMI.Figure 6.5 FTIR spectra of (a) mixture of DGFA and DPMBMI, and (b) mixture o...Figure 6.6 ¹H‐NMR spectra of the mixture of DGFA and DPMBMI kept at 70 °C fo...Figure 6.7 DSC heating trace of the mixture of DGFA and DPMBMI. Heating rate...Figure 6.8 ¹H‐NMR spectra of (a) the adduct of DGFA and DPMBMI and (b) the r...Figure 6.9 ¹³C‐NMR spectra of (a) the adduct of DGFA and DPMBMI and (b) the ...Figure 6.10 FTIR spectrum of DGFA/MHHPA/DPMBMI cross‐linked polymer.Figure 6.11 DSC heating traces of DGFA/MHHPA/DPMBMI cross‐linked polymer (he...Figure 6.12 DSC heating traces of DGFA/MHHPA/DPMBMI cross‐linked polymer (he...Figure 6.13 DMA spectra of DGFA/MHHPA/DPMBMI cross‐linked polymer. (A) As‐ma...Figure 6.14 Visual inspection of thermal remendability of cured DGFA polymer...Scheme 6.7 FGE synthesized by a two‐step route.Figure 6.15 FTIR spectra of (a) raw FGE and (b) its purified version.Figure 6.16 ¹H‐NMR spectrum of FGE.Figure 6.17 13C‐NMR spectrum of FGE.Figure 6.18 DSC heating trace of the mixture of FGE and DPMBMI. Heating rate...Figure 6.19 FTIR spectra of (a) the mixture of FGE and DPMBMI and (b) the ad...Figure 6.20 ¹H‐NMR spectra of the mixture of FGE and DPMBMI kept at 60 °C fo...Figure 6.21 1H‐NMR spectra of (a) the adduct of FGE and DPMBMI and (b) the r...Figure 6.22 13C‐NMR spectra of (a) the adduct of FGE and DPMBMI and (b) the ...Figure 6.23 FTIR spectrum of cured FGE/MHHPA/DPMBMI polymer.Figure 6.24 DSC heating traces of cured FGE/MHHPA/DPMBMI polymer (heating ra...Figure 6.25 FTIR spectra of cured DGFA/FGE blends. The sample IDs and compos...Figure 6.26 DSC heating traces of the cured blends of DGFA and FGE (heating ...Figure 6.27 DMA spectra of the cured blends of DGFA and FGE: (a) DF91; (b) D...Figure 6.28 Molecular weight between cross‐links of the cured epoxy, M_c, and...Figure 6.29 Characteristic surface Raman peak area ratios of the cured blend...

7 Chapter 7Scheme 7.1 Dissociation–association of alkoxyamine derivatives.Scheme 7.2 Dynamic crossover or exchange reactions in blended PCMS polymers ...Scheme 7.3 Synthesis of PCMS‐TEMPO. 2, 1‐hydroxy‐2,2,6,6‐tetramethylpiperidi...Scheme 7.4 Synthesis of PCMS‐TEMPO‐EOPh. 6, 1‐(1‐phenyl‐ethoxy)‐2,2,6,6‐tetr...Figure 7.1 Gel formation due to crossover reaction of macromolecular radical...Figure 7.2 DSC heating traces of PCMS‐TEMPO, PCMS‐TEMPO‐EOPh and PCMS‐TEMPO/...Scheme 7.5 Dissociation–association of alkoxyamine 6 (HO‐TEMPO‐EOPh). 13, 4‐...Figure 7.3 Repeated ESR spectra of alkoxyamine 6 (HO‐TEMPO‐EOPh) recorded du...Figure 7.4 Temperature dependence of relative ESR signal intensities.Figure 7.5 Temperature dependence of relative ESR signal intensities.Scheme 7.6 Dissociation–association of a mixture of alkoxyamines 6 and 14. 1...Figure 7.6 ESR spectra of an equimolar mixture of alkoxyamines 6 (HO‐TEMPO‐E...Figure 7.7 ESR spectra of PCMS‐TEMPO/PCMS‐TEMPO‐EOPh blends recorded at diff...Figure 7.8 (a) Normalized ESR integral spectra of PCMS‐TEMPO/PCMS‐TEMPO‐EOPh...Scheme 7.7 Dynamic de‐cross‐linking, crossover cross‐linking, or exchange re...Scheme 7.8 Synthetic route of alkoxyamine‐based cross‐linked PS.Figure 7.9 Typical ESR spectra of reversibly cross‐linked PS (with molar fee...Figure 7.10 (a) Normalized absorption lines obtained from ESR data of revers...Figure 7.11 (a, b) Pyrolytic behaviors of linear PS, reversibly cross‐linked...Figure 7.12 Temperature dependences of (a) loss factor of reversibly cross‐l...Figure 7.13 DMA spectra of reversibly cross‐linked PS measured by repeated s...Figure 7.14 Typical critical stress, σ_crit versus crack length, l/R, of...Figure 7.15 Temperature dependence of dimensional change for linear PS, reve...Scheme 7.9 Synthesis of alkoxyamine‐containing epoxy (diEP).Scheme 7.10 Thermally remendable epoxy containing alkoxyamines.Figure 7.16 (a) Typical ESR spectra of N‐epoxy measured at various temperatu...Figure 7.17 Relative ESR signal intensities of (a) N‐epoxy and (b) 828/diEP ...Figure 7.18 (a, b) Pyrolytic behaviors of cured epoxies.Figure 7.19 Temperature dependence of (a) storage modulus and (b) tan δFigure 7.20 Temperature dependence of (a) storage modulus and (b) tan δFigure 7.21 Repeated impact damaging‐healing of an 828/diEP specimen.Figure 7.22 Effect of healing time on healing efficiency of 828/diEP. Healin...Scheme 7.11 (a) Dissociation–association of the designed alkoxyamine derivat...Scheme 7.12 (a, b) Synthesis of CTPO.Figure 7.23 Typical ESR spectra of (a1) CTPO and (b1) ICPEG2000 measured at ...Figure 7.24 (a) Impact strengths of virgin ICPEG2000 specimens and the repea...Figure 7.25 Repeated macro‐repairing of impacted ICPEG2000 specimen (tempera...Figure 7.26 (a) Schematic drawing of the sample for depth profile analysis o...Scheme 7.13 Synthesis of PU prepolymers.Scheme 7.14 Synthesis of PU prepolymers.Figure 7.27 Operation principle of the two‐way shape memory effect of the pr...Figure 7.28 Programming of the cross‐linked PU toward two‐way shape‐memory e...Figure 7.29 (a) Typical ESR spectra of the cross‐linked PU collected at vari...Figure 7.30 Typical stress relaxation curves of (a) cross‐linked PU and (b) ...Figure 7.31 (a) Length variation of the programmed cross‐linked PU during he...Figure 7.32 Typical time dependence of strain of the programmed cross‐linked...Figure 7.33 Typical tensile stress–strain curves of the cross‐linked PU heal...Figure 7.34 Shape memory effect assisted intrinsic self‐healing of a wider c...

8 Chapter 8Scheme 8.1 Structures of the disulfide compounds.Scheme 8.2 Macromolecules resembling the target polymer.Figure 8.1 (a) HLPC chromatograms of mixtures containing equivalent amounts ...Scheme 8.3 TBP‐catalyzed metathesis between low‐molecular‐weight disulfides....Scheme 8.4 TBP‐catalyzed disulfide metathesis within a polysulfide network....Figure 8.2 (a) FTIR spectra of EPS‐sh and control‐1 compared with that of EP...Figure 8.3 Storage shear modulus, G′, and loss shear modulus, G″, as functio...Figure 8.4 Typical tensile stress–strain curves of virgin and healed EPS‐sh....Figure 8.5 (a, b) Reshaping and (c, d) reprocessing of EPS‐sh through compre...Figure 8.6 Typical tensile stress–strain curves of recycled EPS‐sh subjected...Figure 8.7 Typical tensile creep strain–time curves for EPS‐sh and the contr...Scheme 8.5 Structures of PU‐HEDS‐400 and its control PU‐BDO‐400.Figure 8.8 (a) HPLC analysis of an equimolar mixture of DEDS and HEDS in ace...Figure 8.9 Absorbance and transmittance of PU‐HEDS‐400 (0.8 mm thick) as a f...Figure 8.10 Images showing repeated healing of scratched PU‐HEDS‐400 film (0...Figure 8.11 (a) Tensile stress–strain curves of virgin and healed PU‐HEDS‐40...Scheme 8.6 Hydrogen bonds formed between PU‐HEDS‐400 macromolecules.Figure 8.12 Sunlight‐aided recycling. (a) Pulverized PU‐HEDS‐400. (b) Molded...Figure 8.13 Tensile stress–strain curves of (a) virgin and solar recycled PU...Figure 8.14 Schematic illustration of fabrication of the sandwich structured...Figure 8.15 (a) UV–visible transmittance spectra of PU and AgNWs/PU composit...Figure 8.16 Relative resistance change, ΔR/R_o, as a function of tensile stra...Figure 8.17 (a) SEM photo of a cross‐section of the sandwiched PU/AgNWs/PU c...Figure 8.18 Typical relative resistance changes, ΔR/R_o, of (a, b) sandwiched...Figure 8.19 Typical relative resistance changes, ΔR/R_o, of (a) sandwiched PU...Figure 8.20 SEM images of (a) the scratched and (b) the sunlight healed surf...Figure 8.21 (a) Quantification of repeated sunlight driven self‐healing of e...Scheme 8.7 Flow chart showing preparation procedures of the cross‐linked sil...Scheme 8.8 Synthesis of the cross‐linked silicone elastomer.Figure 8.22 (a) GC chromatograms of disulfide metathesis between equimolar D...Figure 8.23 Transmittance of SR‐SH and SR‐ref (0.75 mm thick) versus wavelen...Figure 8.24 (a) GPC curves of SS‐MTQ before and after xenon light exposure i...Figure 8.25 Typical tensile stress–strain curves of virgin and healed (a–c, ...Figure 8.26 Recycling of sheeted SR‐SH under 100 mW cm⁻² xenon light e...Figure 8.27 Typical tensile stress–strain curves of recycled SR‐SH: (a) effe...Figure 8.28 Typical tensile stress–strain curves of the virgin, healed and r...Scheme 8.9 Structures of the disulfide‐ and polysulfide‐containing compounds...Figure 8.29 HLPC analysis of an equimolar mixture of HEDS and DEDS as a func...Figure 8.30 Time dependence of number average molecular weight, M_n, weight a...Figure 8.31 (a) UV–visible, (b) electron spin resonance (ESR) and (c) fluore...Figure 8.32 (a) Quantum chemical study of CuCl₂‐catalyzed disulfide metathes...Figure 8.33 Stress relaxation curves of (a) VR‐SH measured at various temper...Figure 8.34 (a–c) Typical tensile stress–strain curves of virgin and healed ...Figure 8.35 (a) Reclaiming of VR‐SH. Sheeted rubber was cut, cryogenically g...