Preparation of an acrylic-grafted polyester and its aqueous dispersion?Effect of the molecular structures of the grafted polyesters on viscosity and rheology of dispersion

Abstract

An investigation was undertaken to develop a new class of water-borne polyesters that have various viscosity and various rheological profiles. We discussed the effect of the grafting condition on the molecular weights of the acrylic segments in the acrylic-grafted polyester. The molecular weights of the acrylic segments could be changed by an initiator concentration, a chain transfer agent concentration, and a monomer concentration. We discussed the viscosity and the rheology of the dispersions obtained from the above-grafted polyesters. The viscosity of the dispersion decreased as the molecular weights of the acrylic segments decreased. It was considered that the interaction between the particles of the dispersions decreased with a decrease in the thickness of the shell layer. The viscosity of the dispersions also decreased as the solubility of the acrylic segments in water decreased. It was considered that the interaction between the particle of dispersion decreased with the shrinkage of the shell layer. The rheological profile of dispersion was changed not by the molecular weights but the composition of the acrylic segments. The dispersions having various rheological profiles could be obtained by the control of the molecular weights or the composition of the acrylic segments in the grafted polyesters.

Rheological behavior of aqueous organosilicone resin emulsion stabilized by colloidal nanosilica particles

“…For example, emulsion polymerization is empolyed to prepare O/W (oil-in-water) latexes, or emulsification technique of polymers in aqueous phase is used for O/W emulsions. Generally, the emulsification of polymers could be performed via following two ways: One is to introduce some base or acid groups into macromolecular chains first during synthesis process, these groups are then neutralized using acid or base compounds, respectively, followed by high shear dispersing [1,2]. Another is to directly post-emulsify polymers (especially oligomers) in aqueous media under high speed shearing with the aid of emulsifiers [3], which form a protection layer on the surfaces of the dispersing phase by steric hindrance, electrostatic repulsion to stabilize the emulsion.…”

Applications for Automotive Coatings

“…They consist of "core-shell" particles with a core of high molecular weight polyester. Small particle diameters were obtained by use of polyesters having the largest amount of unsaturated bonds unless gelation occurs [24][25][26][27][28][29][30]. Thermosetting water based polyester resin coating composition prepared from polyalkadienediol may be directly applied to wet electrodeposited coating [31].…”

Preparation of an acrylics-grafted polyester and its aqueous dispersion?Structural study of acrylics-grafted polyesters

“…They consist of “core‐shell” particles with a core of high molecular‐weight polyester. In previous articles, we discussed the preparation and the characterization of an acrylics‐grafted polyester and its dispersion, i.e., the effect of the grafting conditions, reactivities of the grafting monomers, the grafting solvents,10 the grafting methods11 on the molecular structures of the grafted polyesters, the particle structures,13 the particle diameters of their dispersions,10 and the dispersion viscosity and the dispersion rheology 12. We discussed the mechanical properties of the acrylics‐grafted polyesters to make the factor effecting the mechanical properties clear in our previous article 14.…”