Degradation of Various Low Density Polyethylene Products on Alumina Surface with Sulphuric Acid—DTS Technique

Various low density polyethylene products commonly present in municipal solid waste were degraded on alumina surface with sulphuric acid. Sulphuric acid plays two important roles in the degradation (i) supplies protons to polymer via alumina for the initiation of degradation using triphase catalytic activity of alumina; (ii) acts as a scavenger for degraded fragments. During degradation sulphuric acid was circulating in two step cyclic pattern, dropping towards the hot reaction surface containing polymer and alumina in its first half, and then in its second half sulphuric acid condensed on the upper end of the assembly. This cyclic rotation of sulphuric acid was continuously changing the reaction surface temperature and produced scavenging on the degraded products. Resultant scavenging of the degraded fragments from the different temperature conditions was named as different temperature scavenging (DTS) technique. The application of this technique towards polymeric degradation was justified by using a relative weight loss study. The oily fraction obtained as a result of degradation was thoroughly analyzed by GC- MS measurements. The product selectivity towards liquid function (≈l60-70%) was found to be almost unaffected by the type of polymer but it, principally, influenced the formation of branched hydrocarbons.