Cyclization and characterization of polyisoprene

• Main Authors: Sun, Wen-bin, 孫文彬
• Other Authors: J.H.Liu, J.H.Wang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/10231085408512801126

碩士 === 國立成功大學 === 化學工程學系 === 84 === Abstract Cyclization of polyisoprene by sulfuric acid in tetra-hydrofuran solvent was investigated in this paper. Effects of concentration of sulfuric acid, and the molecular weight of polyisoprene on the cyclization were investigated. The glass transition temperature, mechanical properties and transparency of polyisoprene before and after photo-curing were also studied. Cyclization of polyisoprene was carried out in the presence of sulfuric acid and aluminum chloride in tetra-hydrofuran and toluene. It was found that the cyclization of polyisoprene by using sulfuric acid as a catalyst in tetrahydrofuran was better than in toluene, and the degree of cyclization was increased with increasing the amount of solvent. Effect of temperature on the cyclization of polyiso-prene was also investigated. It was found that the degree of cyclization was increased with increasing the reaction temperature, and the intromolecular cyclization occurred effectively at the relatively lower temperature. However, the transmittance decreased with increasing the degree of cyclization. In addition, the tensile strength increased with increasing the degree of cyclization, and the physical properties were further enhanced after photo-irradiation.