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

Abstract

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.

Water Barrier Properties of Resin‐Stabilized Waterborne Coatings for Paperboard

“…Starch-based coating [49] Paper Cobb = 20 g m −2 after 60 s Butyl acrylate/methyl methacrylate latex stabilized with SDS [50] Glass 100% mass increase within 100 min immersion in water Butyl acrylate/methyl methacrylate stabilized by poly(acrylamide) (PAM) or poly(acrylic acid) (PAA) [51] Freestanding film 29% and 27% mass increase after 12 h of immersion in water for PAM and PAA stabilized latexes respectively…”

Quantification for the Mixing of Polymers on Microspheres in Waterborne Latex Films

“…Especially, small-angle X-ray scattering (SAXS) and neutron scattering (SANS) are powerful tools for the characterization of the microscopic structures (1–100 nm) within the sample, − which cover the colloidal dimension. These SAS techniques have been applied to characterize the coalescence behavior and the colloidal crystalline structures of latex films. − Although the crystalline structures offer information pertaining to the packing structure in the films, the information on the microscopic interpenetration behavior is not directly reflected. Additionally, the penetration depth of the coalescence between polymer chains of adjacent microspheres has been characterized by calculating the radius of gyration ( R g ) of the microspheres in the film using SANS. − However, this method is experimentally limited as mixed matrixes that include deuterated and protonated microspheres are required.…”

Tracking Hydroplasticization by DSC: Movement of Water Domains Bound to Poly(Meth)Acrylates during Latex Film Formation

“…Bound The quantification of the bound water for the samples immersed in water for one week provides insight to the water distributed in the final dried polymer film. This measurements could be of interest when studying the water uptake by latex containing different surface functionalities [32] or when analyzing the underwater adhesion properties [33]. However, this is a redistribution of water reentering into a formed polymer matrix of a dried latex film.…”