A Bi-Order Kinetic Model for Poly(methyl methacrylate) Decomposition in HNO3 Using Microwave Irradiation

作者：Lin, Chun Chih^*; Guo, Gia Luen; Tsai, Tsuey Lin

来源：AIChE Journal, 2009, 55(8): 2150-2158.

DOI：10.1002/aic.11813

• reaction kinetics
• mathematical modeling
• microwave digestion
• degradation
• polymer properties

In this study, a novel bi-order model combined with zero- and first-order kinetics was proposed,for the decomposition of PMMA (MW = 120,000 g/mol) in concentrated HNO3 by microwave irradiation. To develop and validate this model, Fourier Transform Infrared spectroscopy, scanning electron microscopy, fractional-life method, the gravimetric analysis and Newton's method were utilized. Rate constants, activation energies, the pre-exponential factors and the weight fractions (Phi) via main-chain scission for the decomposition at 423-453 K were derived from this model. The zero-order reaction was observed dominant at 423-443 K, while the first-order reaction dominated at 453 K and 473 K. The digestion efficiency increased as HNO3 was increased to >3 mL at 423 K-443 K. At 473 K. the digestion was almost 100% when HNO3 volume was >3 mL. The estimated Phi values increased with HNO3 volume at 423 and 443 K, but varied insignificantly at 453 and 473 K.

• 出版日期2009-8
• 单位南华大学