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Use of a Routh–Russel Deformation Map To Achieve Film Formation of a Latex with a High Glass Transition Temperature
journal contribution
posted on 2013-02-12, 00:00 authored by Edurne Gonzalez, María Paulis, María
Jesús Barandiaran, Joseph L. KeddieIn the film formation of latex, particle deformation
can occur
by processes of wet sintering, dry sintering, or capillary action.
When latex films dry nonuniformly and when particles deform and coalesce
while the film is still wet, a detrimental skin layer will develop
at the film surface. In their process model, Routh and Russel proposed
that the operative particle deformation mechanism can be determined
by the values of control parameters on a deformation map. Here, the
film formation processes of three methyl methacrylate/butyl acrylate
copolymer latexes with high glass transition temperatures (Tg), ranging from 45 to 64 °C, have been
studied when heated by infrared radiation. Adjusting the infrared
(IR) power density enables the film temperature, polymer viscosity,
and evaporation rate during latex film formation to be controlled
precisely. Different polymer particle deformation mechanisms have
been demonstrated for the same latex under a variety of film formation
process conditions. When the temperature is too high, a skin layer
develops. On the other hand, when the temperature is too low, particles
deform by dry sintering, and the process requires extended time periods.
The deduced mechanisms can be interpreted and explained by the Routh–Russel
deformation maps. Film formation of hard (high Tg) coatings is achieved without using coalescing aids that
emit volatile organic compounds (VOCs), which is a significant technical
achievement.