| 초록 |
The UV- degradation and discoloration mechanisms of the PP composite system were investigated. The technical approaches include optical microscopy, video microscopy, scanning electron microscopy, energy dispersive spectroscopy, Fourier- transform infrared spectroscopy and pyrolysis-GC/MS. Microscopy observations showed that surface degradation was occurred, followed by massive surface crackings. FTIR analysis indicated that olefinic and carbonyl groups arisen from chain-scission were accumulated after exposing UV condition. It was clearly found that the debonding between carbon black particle and PP matrix. This leaded the discoloration from black to chalky white at exposed surface of the PP composite. This discoloration phenomenon can be related to the combination of the debonding between carbon black particle and PP matrix, and the migration of calcium component from the bulk of PP composite. |
