Pyrolysis mass spectrometric analysis of styrene-isoprene-styrene copolymer

Thermal analysis of styrene-isoprene-styrene block copolymer, using the dir ect pyrolysis mass spectrometry (MS) technique, indicated that each block s howed very similar thermal behavior with the corresponding homopolymer, The isoprene block was found to be thermally less stable, decomposing by rando m scissions followed by cyclization reactions. The more stable styrene bloc k degraded by a radical depolymerization mechanism. With an indirect pyroly sis MS technique, it was found that production of benzene, toluene, 1-methy l cyclopentene and 1-methyl cyclohexene was more effective when degradation was carried out in a closed reactor. (C) 1999 Elsevier Science Ltd. All ri ghts reserved.