Study of multivesiculated polyester particles synthesis by double emulsion process

Dias, Ângela; Fidalgo, Joana; Machado, João; Moniz, Jorge; Mendes, Adélio; Magalhães, Fernão D.

doi:10.1016/j.eurpolymj.2013.01.004

Cited by 6 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The large refractive index difference between polymer shell and entrapped air results in scattering of incident light, increasing the opacity of a coating loaded with these particles. MVPs can therefore partially replace the costly titanium dioxide pigment traditionally used .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of multihollow polyester particles in supra- and infra-millimeter size ranges by double emulsion process

et al. 2016

Self Cite

View full text Add to dashboard Cite

Multivesiculated particles (MVPs) are obtained from a double emulsion system, being currently used as opacifying agents by waterborne paint industry. They have high mechanical resistance and low density as a result of a rigid multialveolar structure formed by cross-linked poly-ester. Depending on the particle sizes, different novel applications can be envisaged. This work studies how the conventional one-step batch emulsification approach can be adapted for producing MVPs with average diameters ranging from tens of microns to a few millimeters. The Taguchi method was employed to identify the level of influence of several process variables on the final yield of small (<100 m) or large (>1 mm) particles. Poly(vinyl alcohol) (PVA) concentration and molecular weight proved to be the most significant factors to obtain small particles. For large particles, the most significant factors were the PVA molecular weight and the stirring rate during the curing phase. Uniform vesiculation and low particle density could only be obtained by adjusting the stirring conditions during dispersion of the organic phase, due to limitations in water diffusion rate into large organic droplets. Large particles exhibited tendency to fracture due to residual stresses, but this problem was solved by using an organic-soluble cure initiator.

show abstract

Section: Introductionmentioning

confidence: 99%

“…MVPs are produced by a double emulsion process that yields crosslinked polyester particles with diameters between 1 and 10 μm . Their interior consists of multiple homogeneously distributed spherical microalveoli separated by thin polymer walls.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of multihollow polyester particles in supra- and infra-millimeter size ranges by double emulsion process

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…Multivesiculated polyester particles (MVPs) are an example of hollow polymeric microparticles that have been used as opacifying agents in paint and paper industries, taking advantage of the refraction index difference between the polymer and the air contained in the multiple inner voids [1,2]. They are produced in a conventional batch stirred tank reactor, with sizes ranging from a few to tens of microns.…”

Section: Introductionmentioning

confidence: 99%

“…We have previously studied the conventional stirred reactor process for MVPs production, in the context of use as waterborne paint opacifying agents [2]. The most relevant properties for this application are particle size distribution, internal vesiculation morphology, and dry film opacity.…”

Section: Introductionmentioning

confidence: 99%

Physicomechanical characterization of monodisperse multivesiculated polyester particles

Fidalgo¹,

Mendes²,

Magalhães³

2014

European Polymer Journal

Self Cite

View full text Add to dashboard Cite

This work describes physicomechanical properties of low-density polyester particles with multialveolar inner morphology, obtained via a water/oil/water double emulsion process. Monodisperse particle diameters were produced thanks to the use of a microchannel T-junction device for droplet generation. The drying conditions tested showed that rapid water evaporation at 120 o C, combined with slow diffusion towards the exterior, causes internal fracture and particle deformation. Interestingly, all particles present virtually identical internal damage and external deformation features under these drying conditions, demonstrating the uniformity in internal structures. Drying at 70 o C allows for efficient water removal with no damage. Thermomechanical transitions and thermal stability were analyzed by dynamic mechanical analysis (DMA in single-particle compression mode), dynamic scanning calorimetry (DSC) and thermogravimetry (TG). The effectiveness of curing conditions was evaluated by FTIR and DSC, allowing to identify the need of a thermal post-treatment for consumption of residual styrene. The consequent increase in degree of crosslinking produced a positive shift in glass transition temperature measured by DMA. Finally, mechanical reinforcement of the multivesiculated polyester particles was obtained by loading the polymer with surface-modified fumed silica, yielding 75% increase in storage modulus.

show abstract

“…In a previous study, we have studied in detail how this phenomenon relates to the internal vesiculated structure of MVPs . In another work, we have studied how relevant operation parameters of the organic phase emulsification step influence the properties of the resulting MVPs .…”

Section: Introductionmentioning

confidence: 99%

Effect of curing conditions on the properties of multivesiculated polyester particle dispersions

Dias

Machado²,

Moniz³

et al. 2013

Polym Eng Sci

Self Cite

View full text Add to dashboard Cite

Resiquímica -Resinas Químicas S.A., Rua Francisco Lyon de Castro, 28, 2725-397 Mem-Martins, Portugal Multivesiculated polyester particles were synthesized from a double emulsion system comprising water and a solution of unsaturated polyester in styrene. A suspension of solid microparticles containing multiple water-filled vesicles is obtained after curing (i.e., cross-linking) the dispersed organic phase. These have several applications, like opacifying agents in paint formulations. The effects of curing time and temperature on relevant properties of the final product (particle size distribution, dry film opacity, dispersion viscosity, and stability) were investigated. Results showed that more than 1 h was necessary when curing at room temperature, in order to avoid coalescence and loss of opacity upon drying. On the other hand, well-individualized particles were obtained within a few minutes when curing above 60 o C, and the internal alveolar structure was preserved after drying. Furthermore, high curing temperatures enhanced not only the final dry film opacity, but also originated less viscous and more stable particle dispersions. POLYM. ENG. SCI.,

show abstract

Study of multivesiculated polyester particles synthesis by double emulsion process

Cited by 6 publications

References 4 publications

Synthesis of multihollow polyester particles in supra- and infra-millimeter size ranges by double emulsion process

Synthesis of multihollow polyester particles in supra- and infra-millimeter size ranges by double emulsion process

Physicomechanical characterization of monodisperse multivesiculated polyester particles

Effect of curing conditions on the properties of multivesiculated polyester particle dispersions

Contact Info

Product

Resources

About