MODEL FOR VAPOR-DEPOSITION POLYMERIZATION OF PARA-XYLYLENE

A model is developed for the vapor deposition and polymerization of p-xylylene which links the process variables of temperature, pressure, and rate of growth with molecular rate constants, diffusional mass transport, and molecular weight. For an important limiting case, an approximate solution is extracted which predicts the interdependence of process variables and polymer properties. Data from the literature regarding the polymerization of p-xylylene are used to set up exemplary model parameters to describe the conditions present in a typical vapor deposition polymerization. The picture which emerges is that the polymer is formed within a few thousand angstroms of the growth surface in a medium which is best described as a slightly swollen solid. © 1978, American Chemical Society. All rights reserved.