Selective Adsorption of Aqueous Phase Co‐Oligomers on Latex Particles Part 1: Influence of Different Initiator Systems

Daswani, Pooja; Herk, Alex van

doi:10.1002/mats.201600047

Cited by 7 publications

(5 citation statements)

References 21 publications

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“…The latex particles of the D2–D5 systems have a surface hydrophilic layer built of poly(acrylamide) (PAM) (D2), poly(acrylic acid) (PAA) (D3), and their statistical copolymers (PAA-AM) (D4 and D5). According to the known mechanism of emulsion polymerization, a large part of the PAA and PAM is incorporated into the growing polymer chain in the water phase before it reaches the critical entry length and enters the particle . Due to this mechanism, most polymer chain ends consist of a sulfate end group and a hydrophilic segment built from PAA and/or PAM.…”

Section: Methodsmentioning

confidence: 99%

“…According to the known mechanism of emulsion polymerization, a large part of the PAA and PAM is incorporated into the growing polymer chain in the water phase before it reaches the critical entry length and enters the particle. 58 Due to this mechanism, most polymer chain ends consist of a sulfate end group and a hydrophilic segment built from PAA and/or PAM. These polar segments are located preferentially at the particle surface and form the so-called "hairy layer".…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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Role of the Hydrophilic Latex Particle Surface in Water Diffusion into Films from Waterborne Polymer Colloids

Konko

Guriyanova²,

Boyko³

et al. 2019

Langmuir

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The diffusion mechanism and growth of large-scale domains during the immersion of latex films in water have been thoroughly investigated with scattering techniques in a combination with the gravimetric method. Latex dispersions for film formation studies had identical main monomer compositions and only differ in the hydrophilic comonomers that result in distinct “hairy” layer structures of the particles. The major effects of the presence and the structure of the surface layers were identified: (1) Introducing the hydrophilic surface layer in the binder structure results in a more uniform penetration of water and a reduction in the water domain growth. (2) The nature of the particle shell defines the rate of the formation of the first hydration layer and the beginning of the large cluster formation. Poly(acrylamide) in the particle shell promotes the formation of the homogeneously swollen film and slows down the development of water “pockets.” Poly(acrylic acid) leads to a more heterogeneous material and accelerates water uptake and cluster growth. (3) The thickness of the particle hairy layer regulates the thickness of the interstitials in the dry film and the number of the chemical groups involved in H-bonding with water molecules without a cluster formation. The amount of water that was absorbed before large domains start evolving increased with the growth of the particle shell thickness.

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Section: Methodsmentioning

confidence: 99%

Section: ■ Experimental Sectionmentioning

confidence: 99%

Role of the Hydrophilic Latex Particle Surface in Water Diffusion into Films from Waterborne Polymer Colloids

Konko

Guriyanova²,

Boyko³

et al. 2019

Langmuir

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show abstract

“…In light of this observation, we believed that the secondary nucleation is caused by the presence of low-molecular-weight, water-soluble P(MAA- co -MMA) macromonomers produced during the catalytic chain transfer emulsion polymerization step. The critical chain length for PMMA to be soluble in water was estimated by van Herk et al to be DP 10, analogous to j-crit in emulsion polymerization . When targeting DP of 30, the % mol/mol of oligomers with DP ≤ 10 by GPC was estimated by calculation from the number distribution to be 12.46% w/w (assuming no dependence of detector signal on chain length), which corresponds to 4.6 mM at the start of subsequent chain extension seeded emulsion polymerization.…”

Section: Resultsmentioning

confidence: 99%

“…The critical chain length for PMMA to be soluble in water was estimated by van Herk et al to be DP 10, analogous to j-crit in emulsion polymerization. 57 When targeting DP of 30, the % mol/mol of oligomers with DP ≤ 10 by GPC was estimated by calculation from the number distribution to be 12.46% w/w (assuming no dependence of detector signal on chain length), which corresponds to 4.6 mM at the start of subsequent chain extension seeded emulsion polymerization. During the reaction, the water-soluble oligomers chain-extend with BMA, reach a critical chain length, and form the lowmolecular-weight secondary crop of latex particles.…”

Section: ■ Introductionmentioning

confidence: 99%

On Particle Size Distributions in Catalytic Chain Transfer Emulsion Polymerization: Chain-Extension and the Use of Derived Macromonomers as Reactive Surfactants in Emulsion Polymerization

2020

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Catalytic chain transfer emulsion polymerization (CCTP) and subsequent chain extension via reversible addition− fragmentation chain transfer (RAFT) were used to synthesize amphiphilic macromonomers (MM), in the form of polymer latexes. The macromonomers consisted of two blocks whose first was a random copolymer of methacrylic acid and methyl methacrylate, at 35:65 mol:mol, while the second block was n-butyl methacrylate P[(MAA-co-MMA)-block-PBMA]. The block copolymer colloids were disintegrated and micellized upon addition of ammonia. The resulting nanosized polymer dispersions were used as reactive surfactants in the emulsion polymerization of n-butyl methacrylate. For this, a dual stage slow−fast monomer feed profile was used. The final polymer latexes were in the sub-100 nm range for the particle diameter at 30% w/w total polymer content. The emphasis of the work is to discuss and find an explanation for the observed particle size distributions in the three consecutive emulsion polymerization steps. The particle size distribution of the ω-unsaturated macromonomer latex synthesized by CCTP emulsion polymerization was found to be much broader than expected. This discrepancy is attributed to an extended particle nucleation period. The chain extension step in the macromonomer latex preparation showed considerable secondary nucleation. The presence of water-soluble macromonomer species from the CCTP emulsion polymerization step assured that control of chain growth persisted. The use of the amphiphilic macromonomers as reactive surfactants in the form of a nanosized aggregate seed dispersion showed that the average particle diameter could be tuned and that the molecular weight distributions could be regulated, when monomer starved conditions were used in the emulsion polymerizations.

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“… 16 Actually, the existing models could not explain the competitive growth of particles of different size. 36 The complexities of chain growth at low degrees of polymerization, especially in polar media where the rate coefficient of propagation can vary by an order of magnitude 43 and the nature of entry for copolymerization systems with monomers of different hydrophobicities, 44 − 46 are some of the reasons for the failure of the current models.…”

Section: Fundamental Challenges In the Production Of Emulsion Polymersmentioning

confidence: 99%

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

et al. 2023

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Polymer colloids are complex materials that have the potential to be used in a vast array of applications. One of the main reasons for their continued growth in commercial use is the water-based emulsion polymerization process through which they are generally synthesized. This technique is not only highly efficient from an industrial point of view but also extremely versatile and permits the large-scale production of colloidal particles with controllable properties. In this perspective, we seek to highlight the central challenges in the synthesis and use of polymer colloids, with respect to both existing and emerging applications. We first address the challenges in the current production and application of polymer colloids, with a particular focus on the transition toward sustainable feedstocks and reduced environmental impact in their primary commercial applications. Later, we highlight the features that allow novel polymer colloids to be designed and applied in emerging application areas. Finally, we present recent approaches that have used the unique colloidal nature in unconventional processing techniques.

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Selective Adsorption of Aqueous Phase Co‐Oligomers on Latex Particles Part 1: Influence of Different Initiator Systems

Cited by 7 publications

References 21 publications

Role of the Hydrophilic Latex Particle Surface in Water Diffusion into Films from Waterborne Polymer Colloids

Role of the Hydrophilic Latex Particle Surface in Water Diffusion into Films from Waterborne Polymer Colloids

On Particle Size Distributions in Catalytic Chain Transfer Emulsion Polymerization: Chain-Extension and the Use of Derived Macromonomers as Reactive Surfactants in Emulsion Polymerization

Polymer Colloids: Current Challenges, Emerging Applications, and New Developments

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