CATALYTIC CRACKING OF POLYISOPRENE OVER SOLID BASE CATALYST
Keywords:
Catalytic cracking, solid base catalyst, polyisoprene, zeolites, metal oxideAbstract
This research involved the thermal cracking and catalytic cracking of polyisoprene using solid base catalysts. BaO, BaCO3, MgO, zeolite X and zeolite Y were used as the catalyst. The reactions were carried out at 360o C, 425o C and 475o C in a batch reactor under nitrogen atmosphere. The products were ranged from gases, liquid hydrocarbons, wax–like compounds and carbonnaceous residues. It was found that the higher thermal cracking temperature of polyisoprene, the higher gas and liquid products were obtained. The highest yield of gas and liquid products was achieved at 475o C whereas the highest selectivity of isoprene was occurred at 425o C. Catalytic cracking had no effect on enchanced yield of gas and liquid products while it improved the selectivity of isoprene monomer. In addition, zeolite X showed higher selectivity than zeolite Y for isoprene production. BaCO3 showed the highest selectivity compared to metal oxides and exhibited the highest yield of isoprene (56%) at 425o C.
References
ดารณี พิมพากรณ์, พิริยา พุทธิมัย และสุภาภัค ชูโต. (2542). โครงงานพิเศษเรื่องการสลายตัวของพอลิสไตรีนโดยใช้ตัวเร่งปฏิกิริยาที่เป็นเบส. ภาควิชาเคมี คณะวิทยาศาสตร์ สถาบันเทคโนโลยีพระจอมเกล้าเจ้าคุณทหารลาดกระบัง, หน้า 38-55.
Bhowmick, A.K., Rampalli, S., Gallagher, K., Seeger, R., and Mcintyre, D. (1987). The degradation of guayule rubber and the effect of resin components on degradation at high temperature. Journal of Applied Polymer Science, 33:1,125-1,139.
Dragunski, D.C., Freitas, A.R., Rubira, A.F., and Muniz, E.C. (2000). Influence of iron (III) chloride on the degradation of the polyisoprene and polybutadiene. Polymer Degradation and Stability, 67:239-247.
Haung, M., Kaliaguine, S., and Auroux, A. (1995). Lewis basic and lewis acidic sites in zeolites. Studies in Surface Science and Catalysis, 97:311-318.
Hocevar, S., and Drzaj, B. (1982). Electronegativity and catalytic properties of zeolites. Journal of Catalysis, 73:205-215.
IRSG Rubber Industry Report. (2003). World rubber industry statistics. The Rubber, 12(5):92.
Lin, R., and White, R.L. (1997). Acid-catalyzed cracking of polystyrene. Journal of Applied Polymer Science, 63:1,287-1,298.
Singh, R., and Dutta, P.K. (1999). Use of surface-modified zeolite Y for extraction of metal ions from aqueous to organic phase. Microporous and Mesoporous Materials, 32:29-35.
Sooknoi, T., and Dwyer, J. (1995). Hydrogenation of styrene and hydrogenolysis of 2-phenylethanol. Studies in Surface Science and Catalysis, 97:423-432.
Woo, O.S., Ayala, N., and Broadbelt, L.J. (2000). Mechanistic interpretation of base-catalyzed depolymerization of polystyrene. Catalysis Today, 55:161-171.
