Tuning the modulus of nanostructured ionomer films of core–shell nanoparticles based on poly(n-butyl acrylate)

Musa, M.; Milani, Amir H.; Shaw, Peter; Simpson, Gareth; Lovell, Peter A.; Eaves, Elizabeth; Hodson, Nigel; Saunders, Brian R.

doi:10.1039/c6sm01563h

Cited by 8 publications

(4 citation statements)

References 42 publications

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“…Strategies to form mechanically strong films from waterborne polymer dispersions include the use of both chemical − and physical − crosslinking, but this complicates the chemistry of the system. Another possibility is to blend soft and hard polymer particles. − However, this often leads to phase separation during film formation.…”

Section: Introductionmentioning

confidence: 99%

Cracking in Films Cast from Soft Core/Hard Shell Waterborne Polymer Dispersions

et al. 2023

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Soft core-hard shell waterborne polymer dispersions are promising for achieving no-volatile organic compound, mechanically strong coatings able to form films at low temperatures. However, the resistance to deformation of the hard phase creates stresses that may lead to the cracking of the coating, which is catastrophic for substrate protection. Cracking is what hinders the broad use of soft core-hard shell latexes for demanding applications that require thick coatings. This article reports on a thorough study of the effect of particle characteristics and drying conditions on stress generation and crack formation. The morphology of particles and films is characterized in detail. The range of conditions necessary to form a crack-free, mechanically strong, lowtemperature film-forming coating is determined. It is shown that the existing mathematical models for cracking are not able to explain the experimental data, and reasons for the failure are discussed. A data-derived criterion for cracking nucleation is proposed.

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Section: Introductionmentioning

confidence: 99%

Cracking in Films Cast from Soft Core/Hard Shell Waterborne Polymer Dispersions

et al. 2023

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“…Furthermore, the formation of a percolating network between methacrylic acid containing latex (40% solid content, s.c.) and ZnO nanoparticles was reported, resulting in tunable mechanical properties [ 29 ]. Likewise, it was demonstrated that the addition of ZnO/KOH inorganic material into a latex containing methacrylic acid groups (45% s.c.) led to the formation of an ionic network that improved the elastic modulus of the material [ 30 ].…”

Section: Introductionmentioning

confidence: 99%

Ionic Inter-Particle Complexation Effect on the Performance of Waterborne Coatings

2021

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The performance of waterborne (meth)acrylic coatings is critically affected by the film formation process, in which the individual polymer particles must join to form a continuous film. Consequently, the waterborne polymers present lower performance than their solvent-borne counter-polymers. To decrease this effect, in this work, ionic complexation between oppositely charged polymer particles was introduced and its effect on the performance of waterborne polymer films was studied. The (meth)acrylic particles were charged by the addition of a small amount of ionic monomers, such as sodium styrene sulfonate and 2-(dimethylamino)ethyl methacrylate. Density functional theory calculations showed that the interaction between the selected main charges of the respective functional monomers (sulfonate–amine) is favored against the interactions with their counter ions (sulfonate–Na and amine–H). To induce ionic complexation, the oppositely charged latexes were blended, either based on the same number of charges or the same number of particles. The performance of the ionic complexed coatings was determined by means of tensile tests and water uptake measurements. The ionic complexed films were compared with reference films obtained at pH at which the cationic charges were in neutral form. The mechanical resistance was raised slightly by ionic bonding between particles, producing much more flexible films, whereas the water penetration within the polymeric films was considerably hindered. By exploring the process of polymer chains interdiffusion using Fluorescence Resonance Energy Transfer (FRET) analysis, it was found that the ionic complexation was established between the particles, which reduced significantly the interdiffusion process of polymer chains. The presented ionic complexes of sulfonate–amine functionalized particles open a promising approach for reinforcing waterborne coatings.

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“…The reason is the so-called film formation dilemma of the waterborne coatings, that in order to form a good film, they need to have a low glass transition temperature ( T g ), but to achieve good mechanical properties, a high T g is needed. Out of the alternatives available to overcome this dilemma, − the use of latexes comprising a soft core covered by patches of a hard polymer (this morphology is referred to as soft core–hard “shell”) is one of the more promising approaches. − The advantage with respect to a well-defined soft core–hard shell morphology is that the particles with a discontinuous shell deform more easily during film formation and yield a film morphology consisting of a honeycomb structure of the hard polymer filled with the soft polymer. However, although this structure results in very good mechanical properties, ,− the presence of a hard polymer at the surface of the particles increases the stress generated during film formation that often results in cracking, , which is catastrophic for substrate protection. , It is worth mentioning that cracking occurs more easily in thick films, which are needed for demanding applications.…”

Section: Introductionmentioning

confidence: 99%

Solving the Film Formation Dilemma: Blends of Soft Core–Hard “Shell” Particles

Abdeldaim,

González,

Duarte

et al. 2023

Macromolecules

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The use of soft core−hard "shell" polymer particles is an alternative to overcome the film formation dilemma (achieving, at the same time, good film formation at a low temperature and good mechanical properties at a usually higher service temperature). In this article, blends of soft core−hard "shell" particles of different sizes have been prepared, and it has been observed that by adding tiny amounts of small particles (e.g., 1 wt %) to big particles, film formation can be substantially improved (lower minimum film formation temperature (MFFT) and higher critical cracking thickness (CCT)). Furthermore, mechanical properties of the films are also improved (higher elongation at break and toughness, maintaining Young's modulus and the stress at break) without affecting the water sensitivity of the film. It has been found that the viscoelastic properties of the small particles must be similar to those of the large ones in order to have a significant effect.

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Tuning the modulus of nanostructured ionomer films of core–shell nanoparticles based on poly(n-butyl acrylate)

Cited by 8 publications

References 42 publications

Cracking in Films Cast from Soft Core/Hard Shell Waterborne Polymer Dispersions

Cracking in Films Cast from Soft Core/Hard Shell Waterborne Polymer Dispersions

Ionic Inter-Particle Complexation Effect on the Performance of Waterborne Coatings

Solving the Film Formation Dilemma: Blends of Soft Core–Hard “Shell” Particles

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