OP-II-3

PP-III-48SBA-TYPE CATALYSTS IN DEGRADATION OF POLYPROPYLENEZeynep Obali, Naime Aslı Sezgi, Timur DoğuMiddle East Technical University, Chemical Engineering Department,Ankara, Turkey, z_obali@yahoo.comThe dramatic growth of welfare levels in the second half of the 20 th century hasbeen accompanied by a drastic increase in plastic product use. This unavoidably has ahuge impact on the environment, as it causes a rapid increase in the amount of plasticwaste and hence a large strain on existing disposal methods such as landfill andincineration. Landfill space has been becoming scarce and expensive, a problemintensified by the fact that plastic waste is more voluminous than other waste types.Incineration, on the other side, could produce air pollution problems due to the possibletoxic emissions. An alternative approach to the solution of problem caused by thesewastes is the recycling of them by chemical recovery. In this method, the wasteplastics are thermally non-catalytically or catalytically degraded into gases and oils.Major advantages of the catalytic thermal degradation over the non-catalytic processare lower operating temperatures and higher yields of valuable chemicals [1-3].In this study, pure and Al-containing SBA-type catalysts were synthesized inorder to be tested in the catalytic degradation of polypropylene. The pure SBA-typecatalysts were synthesized using hydrothermal synthesis route and the aluminumcontaining ones were synthesized using impregnation method [4]. Tetraethylorthosilicate was used as the Si source and aluminum isopropoxide and aluminumsulphate were used as the Al sources. It was observed that these materials had highsurface areas in the range of 200-890 m 2 /g and exhibited isotherms of Type IV. Thealuminum incorporation into the structure was very effective. 27 Al MAS NMR spectraof the catalysts exhibited a mixture of tetrahedral and octahedral aluminum. TEMimages showed well-ordered hexagonal arrays of uniform mesopores with channels.After the characterization of these catalysts, their performances have beeninvestigated in polypropylene degradation reaction using a thermal analyzer. TheTGA results showed a marked reduction in the degradation temperature and theactivation energy in the presence of aluminum containing SBA-type catalyst, asshown in Figure 1. In the case of using aluminum isopropoxide as the aluminumsource in the synthesis of the catalysts, the activation energy values were obtained in526