THE INTERDIFFUSION OF POLYMERIC GRADIENT REFRACTIVE INDEX (GRIN) LENS MATERIALS

摘要

The interdiffusion of two miscible polymers used to fabricate GRIN lenses, polymethylmethacrylate (PMMA) and poly(styrene-co-acrylonitrile) (SAN17) with 17% AN content, was studied as a function of contact time during a multilayer coextrusion process. Oxygen permeability increased from following the series model to following a miscible blend model as the number of layers increased from 17 to 1025. A model relating permeability and the interdiffusion state within the layers successfully predicted the observed permeability trends, and was used to determine the mutual diffusion coefficient of PMMA and SAN17.