Development of a Coupled Viscosity‐Polymerization Model for the Synthesis of High Solids‐Low Viscosity Latexes

Abstract

Summary: The development of a model‐assisted methodology for the synthesis of high solids‐low viscosity latexes is presented. A simplified polymerization model for systems with a polydisperse particle size distribution, PSD, was developed. The polymerization model was then coupled with an equation for the computation of the viscosity. Their combination resulted in a powerful tool that helped to screen strategies for the synthesis of high solids‐low viscosity latexes. Furthermore, using the model‐assisted methodology it was possible to determine the workable viscosity boundary for a given formulation. The evolution of the viscosity with the volume fraction was calculated for different polymerization strategies.

High solid content latex: Preparation methods and application

“…Besides, Sudduth equation has great potential for quantitatively determining the effect of the PSD on the viscosity of HSC latexes. In the subsequent work of do Amaral et al [25], they attempted to experimentally determine the magnitude of the two contributions of the particle interaction coefficient (σ and ϕ m ). A series of polymerizations were simulated by using Sudduth's model.…”

Synthesis of High Solid‐Content Latex using Alkali‐Soluble Resin as Sole Surfactant

“…[28] However, the combination of the viscosity equation with a polymerization model [19,20] is preferable. [29] In this work, a polymerization model that calculated the particles competitive growth, Equation (6), was used to update the PSD of the polymer dispersion in order to calculate the viscosity of the latex during the polymerization process.…”

“…The value of the constants used in the simulation have been given elsewhere. [19] A semicontinuous process was selected. The initial charge consisted of a latex obtained by an ASR-stabilized miniemulsion polymerization, [27] and an additional amount of ASR, which would form agglomerates since the preformed polymer particles were fully covered by the ASR molecules.…”

“…[18] Highly concentrated latexes offer many possible advantages, including a higher unitary usage of industrial installations, faster drying rates, and lower shipment costs. [19] Many polymerization procedures can be found in patents Summary: A novel polymerization procedure to synthesize latex stabilized by alkali-soluble resin (ASR) is detailed. According to this process, latexes with a high solid content and low viscosity are obtained using a substantially lower amount of ASR when compared with existing techniques.…”

“…[20] Unfortunately, most of these processes are centered on an empirical basis; not surprisingly it has been considered that the synthesis of high solids/ low viscosity latexes remain more an art than a science. [18] Recently, do Amaral et al [19] proposed a novel coupled viscosity-polymerization model for the synthesis of concentrated latexes. The combination of a competitive growth polymerization model with a low-shear viscosity equation allows the calculation of the progress of the viscosity during the polymerization.…”