Thermal degradation of nitrogen-containing polymers, acrylonitrile-butadiene-styrene and styrene-acrylonitrile

摘要

Thermal degradation of nitrogen (N)-containing recycled plastics (styrene-acrylpnitrile (SAN), acrylonitrile-butadiene-styrene (ABS)) was carried out in a stirred-batch reactor at 300-400℃ under nitrogen stream. The degradation oil began to be generated over 300℃. Recycled SAN plastic was converted to oil with 91.3 wt% yield at 380℃, while only 70.9 wt% of recycled ABS plastics was converted to oil at the same temperature and both oils contained about the same 3.7 wt% nitrogen as an elemental basis. Rate of oil formation from the thermal degradation of SAN was much higher than that of ABS, but showed a similar degradation pattern in terms of chemical composition. In oil products, aromatic contents obtained at 360℃ were 70 wt% for SAN and 79 wt% for ABS, respectively, and decreased to 59 wt% and 57 wt% at 380℃ with increasing degradation temperature. Dominant product of both degradation oils was styrene, and the following was ethylbenzene for ABS, but none in case of SAN. Both oils contained the N-contain-ing plastic additives that give rise to a confusion for the identification of authentic N-containing degradation products.