Laser interferometric technique for measuring polymer cure kinetics

✍ Scribed by O. Dudi; W. T. Grubbs

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 205 KB
• Volume: 74
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19991128)74:9<2133::aid-app3>3.0.co;2-x

✦ Synopsis

An optical interference apparatus for the analysis of polymer curing kinetics is described. The device employs a helium-neon laser and a home-built Michelson interferometer to measure refractive index variations and film thickness variations during film polymerization. The refractive index variation provides a phenomenological measure of the extent of cure. The technique is demonstrated by collecting interferometric curing profiles for a UV photocurable acrylate resin formulation. Systematic comparisons of curing profiles are made as a function of UV illumination intensity and photoinitiator concentration. Several aspects of the curing process are characterized by these interferometric measurements, such as film shrinkage, gel point formation, and the kinetics of photopolymerization inhibition.