A kinetic study in emulsion polymerization of polyurethane‐acrylate hybrids

Amalvy, Javier Ignacio

doi:10.1108/03699420210442301

Cited by 9 publications

(4 citation statements)

References 26 publications

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“…PU/acrylic hybrid dispersions are attractive because the (meth)acrylic polymers are resistant to water and alkalis, and in addition they come at lower costs. These hybrid dispersions can be prepared by using PUDs synthesized as outlined above as the seed in a seeded semicontinuous emulsion polymerization of acrylic monomers. − Alternatively, the NCO-terminated PU prepolymer prepared in solution is isolated, dissolved in (meth)acrylic monomers, and dispersed in water using high shear forces such as ultrasound (for lab-scale) or high-pressure homogenization. The acrylic monomers are subsequently polymerized via miniemulsion polymerization, and the PU can be chain-extended in the dispersed phase prior to or after polymerization. ,,− However, miniemulsification may be a bottleneck in large-scale processes .…”

Section: Introductionmentioning

confidence: 99%

Toward a Green Synthesis of Polyurethane/(Meth)acrylic Dispersions through Control of Colloidal Characteristics

et al. 2018

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Polyurethane (PU)/acrylic waterborne hybrids are an attractive class of materials with wide application possibilities, but their synthesis typically requires significant quantities of solvent which has negative economic and environmental consequences. In this work, solvent-free and surfactant-free polyurethane (PU)/acrylic waterborne hybrids were obtained by synthesizing the PU prepolymer containing carboxylic groups directly in (meth)acrylic monomers that act as solvent. Then, the mixture is dispersed in water; the PU is chain-extended with diamines, and the (meth)acrylic monomers are polymerized. It was found that, against expectations, colloidal stability did not improve with the concentration of carboxylic groups that acted as stabilizing moieties. A combination of MALDI-TOF MS analysis and Monte Carlo simulations revealed that the highly heterogeneous compositions of the short chains of the PU prepolymer and their reaction with the chain-extender in the aqueous phase were responsible for lack of control of the colloidal properties. This problem was overcome by using more hydrophobic chain-extenders that decrease the fraction of PU chains in the water phase. In this way high-solid-content stable dispersions with controlled particle size were obtained. Finally, the properties of the PU/(meth)acrylic films were studied in terms of mechanical properties and water resistance.

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Section: Introductionmentioning

confidence: 99%

Toward a Green Synthesis of Polyurethane/(Meth)acrylic Dispersions through Control of Colloidal Characteristics

et al. 2018

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“…The use of a functional monomer that can introduce double bonds in the PU chains that subsequently can participate in the free‐radical polymerization of (meth)acrylics offers a way to produce grafted hybrids and improve the compatibility between PU and (meth)acrylics . Functional monomers containing both hydroxyl and (meth)acrylic groups are interesting because this dual functionality allows the monomers to react with the isocyanate groups during the formation of the polyurethane and with radicals during the formation of the poly(meth)acrylic chains.…”

Section: Introductionmentioning

confidence: 99%

Role of Grafting on Particle and Film Morphology and Film Properties of Zero VOC Polyurethane/Poly(meth)acrylate Hybrid Dispersions

Mehravar

Ballard

Agirre

et al. 2018

Macro Materials & Eng

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Hybrid waterborne dispersions of polyurethane (PU)/poly(meth)acrylic are widely applied in coating and adhesive products, as well as in many other applications. The synergetic performance of the two component polymers is highly dependent on the ability to control the PU and (meth)acrylic network structure. In this work, the effect of grafting and the impact of macromolecular architecture on the particle and film morphology as well as on the properties of PU/(meth)acrylic hybrid films is investigated. It is shown that with grafting, the absolute molar mass distribution (MMD) is shifted toward higher values as the low molar mass PU chains become incorporated in the (meth)acrylic polymer network. Furthermore, by using different types of functional monomers, the nature of the MMD can be altered. Using transmission electron microscopy (TEM) analysis, it is demonstrated that more homogeneous particle and film morphologies are obtained in the case of grafted hybrids. Finally, the impact of network structure on tensile strength is outlined highlighting that grafted polymer films have higher Young's modulus and strain hardening than the non‐grafted ones.

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“…In previous studies, we examined the kinetic reactions of these systems,22 and we reported the characterization of samples where the acrylic content was varied from 0 to 50 wt %. Higher amounts of acrylic components led to coagulation, and no film‐forming systems were obtained 23.…”

Section: Introductionmentioning

confidence: 99%

Polyurethane/acrylate hybrids: Effects of the acrylic content and thermal treatment on the polymer properties

Peruzzo

Anbinder

Pardini

et al. 2010

J of Applied Polymer Sci

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Polyurethane (PU)/acrylate hybrids with different acrylic contents (10,30, 50, 70, and 90 wt %) were prepared by the polymerization of acrylic monomers in the presence of preformed PU chains with polymerizable terminal vinyl groups. Films obtained by the casting of polymer dispersions before and after thermal annealing were characterized by dynamic light scattering, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), TEM electron energy-loss spectroscopy, differential scanning calorimetry, and gel fraction determination. Small-angle X-ray scattering (SAXS), wide-angle Xray scattering, mechanical properties testing, atomic force microscopy, water contact angle testing, Buchholz hardness testing, and roughness testing of the films were also performed. The effects of the acrylic content and thermal treatment on the structure and properties were determined. TEM showed that a core-shell morphology was formed during polymerization. When the acrylic content increased, smaller particles without core-shell morphologies were observed. TEM energy-loss spectroscopy studies confirmed this observation. Systems with up to 50 wt % acrylic component were homogeneous, as determined by SAXS, before and after thermal annealing. An attempt to incorporate a higher amount of acrylic component led to phase-separated materials with a different morphology and, therefore, different properties. The relationship between the acrylic content and properties did not follow linear behavior.

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A kinetic study in emulsion polymerization of polyurethane‐acrylate hybrids

Cited by 9 publications

References 26 publications

Toward a Green Synthesis of Polyurethane/(Meth)acrylic Dispersions through Control of Colloidal Characteristics

Toward a Green Synthesis of Polyurethane/(Meth)acrylic Dispersions through Control of Colloidal Characteristics

Role of Grafting on Particle and Film Morphology and Film Properties of Zero VOC Polyurethane/Poly(meth)acrylate Hybrid Dispersions

Polyurethane/acrylate hybrids: Effects of the acrylic content and thermal treatment on the polymer properties

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