Diffusion coefficients of acrylic monomers in poly(methyl methacrylate)
Journal
Journal of Polymer Research
Journal Volume
5
Journal Issue
3
Pages
187-191
Date Issued
1998
Author(s)
Abstract
The average diffusion coefficients (Davg) of three acrylic monomers methyl methacrylate (MMA), butyl methacrylate (BtMA) and cyclohexyl methacrylate (ChMA) in poly(methyl methacrylate) (PMMA) were measured by the thermogravimetric (TGA) technique. The measured Davg values were in the range of (0.2-105.7) ×10-7 for a PMMA solid content of 10∼50% and a temperature range of 323-353 K. It was found that the solid content of PMMA, the molar volume of the acrylic monomer and the temperature significantly affected the Davg values. A large decrease in the Davg value was found at the 50% PMMA solid content for all three acrylic monomers. The order of the Davg value for MMA, BtMA, and ChMA was MMA > BtMA > ChMA due to an increasing molar volume. The Davg value was significantly increased with an increasing temperature, especially at a low PMMA solid content. The measured Davg value can be used for predicting the refractive index distribution of gradient-index polymer optical fibers.
Type
journal article