IR laser ablative and conventional decomposition of poly(vinyl phenyl ketone): Different processes and different products

摘要

Pulsed IR laser ablation of poly(vinyl phenyl ketone) results in the formation of CO, C_1-C_4 hydrocarbons, benzene, styrene and phenylacetylene and affords deposition of polymeric films that were examined by EDX-SEM, FTIR, UV and NMR spectroscopies and gel-permeation chromatography. It is revealed that the structure of the films is affected by laser fluence and their M_w distribution is almost identical to that of poly(vinyl phenyl ketone). The formation of the products is accounted for by cleavages of both polymer backbone and pendant group. Conventional heating of poly(vinyl phenyl ketone) yields CO, formaldehyde, methanol and benzene as major volatile products and affords a solid fraction showing substantial fragmentation of the polymer. The different degradation products from both processes are ascribed to different modes of heating and to the wall effect.