Effect of Shell Growth on the Morphology of Polyvinyl Acetate/Polystyrene Inverted Core-Shell Latex Fabricated by Acrylonitrile Grafting

Synthesis and Application of Reactive Acrylic Latexes: Effect of Particle Morphology

The aim of the study is the synthesis and characterization of epoxy functional reactive polyacrylic latexes, e.g., poly (BA-co-MMA-co-AN-co-GMA) with core/shell and non-structured (random) particle morphologies. Additionally, their performance as binders and coating ability in leather finishing were studied. The epoxy functional polymers were synthesized via the seeded emulsion polymerization technique and the obtained latexes were characterized by means of particle size, zeta potential, FTIR, TEM, DSC, DMTA, and TGA. The results showed that the particle size and zeta potential values were very similar for both latexes, except core/shell latex had slightly higher particle size. DSC, TEM, and DMTA studies verified the successful synthesis of core/shell latex morphology. The copolymer films were elastic in nature and had low T_g values (-13 and -20 °C). The performance results showed some different behavior for core/shell and random copolymer coatings. The abrasion resistance of the leather finish with random copolymer as binder exhibited slightly better values, especially in wet conditions. On the other hand, the leathers finished with core/shell binder showed better performance in flexing endurance and the water spotting test.

Styrene-Acrylic Emulsion with "Transition Layer" for Damping Coating: Synthesis and Characterization

In order to study the dynamic mechanical properties of styrene–acrylic latex with a core/shell structure, a variety of latexes were synthesized by semi-continuous seeded emulsion polymerization based on “particle design” with the same material. The latexes were characterized by rotary viscosimeter, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), dynamic mechanical analysis (DMA), and universal testing machine. The effects of difference at the glass transition temperature (T_g) of core and shell and the introduction of the “transition layer” on the damping and mechanical properties of latex film were studied. The results indicate that as the T_g of core and shell gets closer, the better the compatibility of core and shell, from phase separation to phase continuity. Furthermore, the introduction of the “transition layer” can effectively improve the tensile strength and tan δ (max) of the latex film. The tensile strength and maximum loss factor (f = 1 Hz) of latex with the “transition layer” increased by 36.73% and 29.11% respectively compared with the latex without the “transition layer”. This work provides a reference for the design of emulsion for damping coating.