Isocyanate-functionalized latexes: Film formation and tensile properties

✍ Scribed by S. Mohammed; E. S. Daniels; L. H. Sperling; A. Klein; M. S. El-Aasser

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 255 KB
• Volume: 66
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19971205)66:10<1869::aid-app4>3.0.co;2-l

✦ Synopsis

Latexes functionalized with isocyanate groups were prepared by carrying out the emulsion terpolymerization of dimethyl meta-isopropenyl benzyl isocyanate (TMI) with methyl methacrylate and n-butyl acrylate. The film formation of these latexes and the tensile properties of the resulting latex films were studied. The effect of TMI concentration on the film properties was investigated. The locus of the isocyanate groups in the latex particles was controlled by using different polymerization processes. The locus of the functional groups was found to greatly influence the tensile properties of the latex films. Triethyl amine was used as an external catalyst to cure the TMI polymer films. One-component self-curable systems capable of undergoing crosslinking at ambient temperatures were developed by incorporating small amounts of methacrylic acid into the recipe. These systems exhibited significant improvement in tensile properties upon curing. In addition, the shelf-stability of these latexes was found to be excellent.