Preparation of Thermochromic Films from Latexes Made by Miniemulsion Polymerization. Issue 3 (2nd April 2019)

• Record Type: Journal Article
• Authors: Colmán, Maria M. Espinola; García Valdez, Omar; George, Sean; Cunningham, Michael F.; Laqua, Letícia Alves da Costa; Giudici, Reinaldo
• Is Part Of: Macromolecular reaction engineering. Volume 13:Issue 3(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-04-02
• Subjects: free radical polymerization -- miniemulsion polymerization -- nitroxide mediated polymerization -- thermochromic pigment; Polymers -- Periodicals; Polymerization -- Periodicals; Reaction mechanisms (Chemistry) -- Periodicals; Electronic journals; 547.705
• DOI: 10.1002/mren.201900009
• Languages: English
• ISSNs: 1862-832X

Abstract

Abstract: Thermosensitive‐thermochromic pigments are classified as smart materials capable of detecting and/or responding to environmental stimuli, and specifically in this study, changes in temperature that induce a change in the color of the material. This study aims to obtain nanoparticles of poly(styrene‐co‐butyl acrylate) and poly(styrene‐co‐methyl methacrylate), containing thermosensitive‐thermochromic pigments that are incorporated into the monomer droplets in miniemulsion polymerization. Miniemulsion polymerization has the advantage that the pigment particles can be dispersed directly in the monomer droplets and are encapsulated when the miniemulsion droplets are polymerized. Using controlled/living radical polymerization (or Reversible Deactivation Radical Polymerization), it is possible to produce polymers with better control of microstructure and narrower molecular weight distributions. Nitroxide‐mediated polymerization (NMP) is conducted using the BlocBuilder initiator, as well as a conventional free radical polymerization (FRP) using potassium persulfate (KPS) and 2, 2‐azobis(2‐methylpropionitrile) (AIBN). Stable latexes containing the thermosensitive‐thermochromic pigments are obtained by both NMP and FRP. Films are made from the latexes and shown to exhibit thermochromic behavior. Abstract : Polymeric films incorporated with a thermosensitive pigment are prepared from latexes made by miniemulsion polymerization . Stable latexes of poly(styrene‐co‐butyl acrylate) and poly(styrene‐co‐methyl methacrylate) containing the thermochromic pigment are obtained by both nitroxide‐mediated miniemulsion polymerization as well as by conventional free‐radical miniemulsion polymerization. The polymeric films made by drying the latexes exhibit thermochromic behavior.