Kinetics and rheology characterization during curing of dicyanates

✍ Scribed by Yung-Tin Chen; C. W. Macosko

• Book ID: 102657375
• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 720 KB
• Volume: 62
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19961017)62:3<567::aid-app14>3.0.co;2-w

✦ Synopsis

Reaction kinetics and viscosity rise of a liquid dicyanate ester monomer, l,l-bis(4-cyanatophenol)ethane, are characterized and fitted several models. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) are used to obtain the isothermal reaction kinetic data. The liquid dicyanate resin shows second-order reaction kinetics in the early stage and approaches a plateau conversion at longer times with each curing temperature. Experimental data show that the diffusion limitation for dicyanate resin occurs well before the vitrification point. A two-step kinetic model and a Williams-Landel-Ferry-(WLF-) type diffusion-controlled kinetic model are developed to describe the entire range of curing. For the temperature range we studied ( 14O0C-2OO0C), the WLFtype diffusion-controlled kinetic model gives a better prediction than the two-step kinetic model does. The viscosity rise during isothermal curing is characterized using disposable parallel plates. A Castro-Macosko type of equation is used to describe the isothermal viscosity rise.