TURBIDITY STUDY OF THE PROCESS OF FILM FORMATION OF POLYMER PARTICLES IN DRYING THIN-FILMS OF ACRYLIC LATTICES .1. INTRASTRUCTURE OF ACRYLIC LATTICES STUDIED WITH TRANSMISSION SPECTROPHOTOMETRY

The aim of this study is to determine the factors that define the process of film formation of binder particles in drying aqueous dispersion coatings, based on acrylic polymers. The film formation process is investigated with transmission spectrophotometry. In this paper static measurements are used to relate the turbidity behavior of thin latex films with the physical properties of the latex. This paper focuses on the intrastructure in films of concentrated acrylic dispersions. In concentrated latices the binder particles are arranged in closely packed structures, which cause colored light patterns, due to Bragg diffraction. Light waves traveling in the latex film are scattered at the internal structures of the spheres and the water voids. The pattern of the light transmission as a function of wavelength reveals the internal structure of the latex film. The influence of weight fraction, particle size, film thickness, and particle size distribution on the transmission pattern has been investigated. The results are verified with other particle size measurements and imaging techniques. © 1992.