Toughening Up Elastomers are soft polymer materials widely used in industry and daily life. Inspired by recent work on double-network hydrogels, Ducrot et al. (p. 186 ; see the Perspective Gong ) designed interpenetrated network elastomers that contained isotropically prestretched chains as first network. Double- triple-network structures yielded with very high strength toughness comparison corresponding single networks.

Systematic loading and unloading experiments, in uniaxial tension compression, have been performed on a double-network hydrogel exhibiting very high toughness. We observed significant hysteresis during the first cycle that increased strongly with applied maximum deformation. A large was not second cycle, implying initial can be attributed to fracture of covalent bonds primary network. report this type dissipative mechanism for polymer gels time. Assuming entire energy dissipated network...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFailure mechanisms of polymer interfaces reinforced with block copolymersCostantino Creton, Edward J. Kramer, Chung Yuen Hui, and Hugh R. BrownCite this: Macromolecules 1992, 25, 12, 3075–3088Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June 1992https://pubs.acs.org/doi/10.1021/ma00038a010https://doi.org/10.1021/ma00038a010research-articleACS PublicationsRequest reuse permissionsArticle...

Soft polymer networks have seen an explosion of recent developments motivated by new high tech applications in the biomedical field or engineering. We present a candid and critical overview current understanding relation between structure molecular architecture their mechanical properties, restricting ourselves to soft made flexible polymers displaying entropic elasticity. specifically review compare approaches synthesize swollen hydrogels with enhanced toughness, resilient but tough...

The synthesis and mechanical characterization of novel, tough poly(N,N-dimethylacrylamide) (PDMA)−silica hydrogel hybrids are presented to understand the role played by strong physical interactions between silica nanoparticles PDMA polymer on properties chemically cross-linked highly swollen networks. A detailed comparison with unmodified gels indicates that incorporation in increases compression strength fracture toughness notched samples up an order magnitude while increasing its modulus a...

Sandcastle worms have developed protein-based adhesives, which they use to construct protective tubes from sand grains and shell bits. A key element in the adhesive delivery is formation of a fluidic complex coacervate phase. After delivery, transforms into solid upon an external trigger. In this work, fully synthetic situ setting based on coacervation reported by mimicking main features sandcastle worm's glue. The consists oppositely charged polyelectrolytes grafted with thermoresponsive...

Stretchable elastic materials with high strength, toughness, and good ionic conductivity are highly desirable for wearable devices stretchable batteries. Unfortunately, limited success has been reported to attain all of these properties simultaneously. Here, we report a family ionically conductive elastomers (ICEs) without compromise between mechanical (high stiffness, reversible elasticity, fracture resistance) conductivity, by introducing multiple network elastomer (MNE) architecture into...

Abstract The adhesion mechanisms of two acrylic Pressure-Sensitive-Adhesives on a stainless steel probe are investigated with custom-designed tack apparatus. Our setup allows the simultaneous acquisition nominal stress and strain curve, observation adhesive film from underneath transparent substrate. temperature was varied in range -20°C to 50°C debonding rate 1–10000 μm/s. For all conditions we observed, upon debonding, formation cavities at or near interface between film. These initially...

Adhesively bonded elastic layers with thicknesses that are small relative to their lateral dimensions used in a wide variety of applications. The mechanical response the compliant layer when normal stress is imposed across its thickness determined by effects constraints, which characterized ratio thickness. From this degree confinement and from material properties layer, we predict three distinct deformation modes: (1) edge crack propagation, (2) internal (3) cavitation. conditions...

The tack of polymer melts on rigid substrates under conditions short contact times and low pressures is examined. substrate modeled as a random rough surface with distribution asperities heights. true area between the adhesive calculated for given total load elastic modulus substrate. dependence time accounted by introducing relaxation through time-dependent modulus. For relatively high predicted to scale 1/E so that times, tc, (tc/τe)1/2, where τe entanglement time. lower this simple...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCritical molecular weight for block copolymer reinforcement of interfaces in a two-phase polymer blendCostantino Creton, Edward J. Kramer, and Georges HadziioannouCite this: Macromolecules 1991, 24, 8, 1846–1853Publication Date (Print):April 1, 1991Publication History Published online1 May 2002Published inissue 1 April 1991https://pubs.acs.org/doi/10.1021/ma00008a023https://doi.org/10.1021/ma00008a023research-articleACS PublicationsRequest reuse...

Recent experiments have shown that hydrogels with enhanced toughness can be synthesized by incorporating self-healing physical cross-links in a chemically cross-linked gel network. These gels exhibit rate dependent mechanical behavior, suggesting improved properties are closely tied to the breaking and reattaching of temporary In this work, connection between behavior kinetics reattachment is quantified using three-dimensional finite strain constitutive model. The parameters model fitted...

We studied the stress-strain relation of model dual cross-link gels having permanent cross-links and transient over an unusually wide range extension ratios λ strain rates ϵ̇ (or time t = (λ - 1)/ϵ̇). propose a new analysis method separate stress into strain- time-dependent terms. The strain-dependent term is derived from rubber elasticity, while due to failure can be represented as shear modulus which shows same relaxation in small strain. separability applicable except for stiffening...

Abstract The major objective of this article is to present recent advances in the methodology fine tune adhesive performance a PSA. In addition so-called Dahlquist criterion requiring low modulus, we propose two additional rheological predictors properties. first one derived from description detachment linear elastic layer rigid substrate. We made an approximate extension analysis viscoelastic regime and showed that transition interfacial cracks cavitation fibrillation can be quantitatively...

Strain‐induced light emission from mechanoluminescent cross‐linkers in silica‐filled poly(dimethylsiloxane) demonstrates that covalent bond scission contributes significantly to irreversible stress‐softening upon the initial extension, known as Mullins effect. The contain dioxetanes emit force‐induced scission. filled elastomer emits cyclic uniaxial tension, but only on exceeding previous maximum strain. amount of increases with hysteresis energy a power law exponent 2.0, demonstrating...

We study pattern formation during tensile deformation of confined viscoelastic layers. The use a model system [poly(dimethylsiloxane) with different degrees cross-linking] allows us to go continuously from viscous liquid an elastic solid. observe two distinct regimes fingering instabilities: regime called "elastic" interfacial crack propagation, where the wavelength scales only film thickness, and bulk "viscoelastic," instability shows Saffman-Taylor-like behavior. find good quantitative...

Load-bearing biological tissues, such as muscles, are highly fatigue-resistant, but how the exquisite hierarchical structures of tissues contribute to their excellent fatigue resistance is not well understood. In this work, we study antifatigue properties soft materials with using polyampholyte hydrogels (PA gels) a simple model system. PA gels tough and self-healing, consisting reversible ionic bonds at 1-nm scale, cross-linked polymer network 10-nm bicontinuous hard/soft phase networks...

Abstract The rheological and adhesive properties of bis‐urea functionalized low‐molecular‐weight polyisobutylenes (PIBUT) are investigated. polymers, which can interact through supramolecular hydrogen bonds, self‐organize over times the order days at room temperature. This organized structure has been identified by small angle X‐ray scattering (SAXS) its indicate behaviour a soft viscoelastic gel. ordered be disrupted temperature shear so that 80 °C, material behaves as highly fluid no SAXS...

Nanocavitation was detected for the first time in carbon black filled styrene–butadiene rubber (CB-SBR) under uniaxial loading by real small-angle X-ray scattering (SAXS) using synchrotron radiation. A three phase model developed to calculate void volume fraction from invariant Q determined observed SAXS patterns. The normalized Q/Q0, where Q0 is before deformation, greatly increased above a critical extension ratio λonset which we attribute formation of nanovoids. Analysis 2D patterns show...

A classic paradigm of soft and extensible polymer materials is the difficulty combining reversible elasticity with high fracture toughness, in particular for moduli above 1 MPa. Our recent discovery multiple network acrylic elastomers opened a pathway to obtain precisely such combination. We show here that they can be seen as true molecular composites well-cross-linked acting percolating filler embedded an matrix, so stress-strain curves family composite made different volume fractions same...

Embedded spiropyran mechanophores reveal and quantitatively map stresses in soft materials by changing their color.

Normally, a polymer network swells in good solvent to form gel but the shrinks poor solvent. Here, an abnormal phenomenon is reported: some hydrophobic gels significantly swell water, reaching water content as high 99.6 wt%. Such swelling behaviors nonsolvent are observed universally for various organogels containing omniphilic organic solvents that have higher affinity than polymers. The formation of semipermeable skin layer due rapid phase separation, and asymmetric diffusion molecules...