| 초록 |
It is well known that shish-kebab structure of linear polyolefines is formed from the sheared melt. On the other hand, there are no studies on shear induced crystallization of cyclic polyolefines. In order to clarify the role of entanglement species on the formation of shish-kebab structure, we measured formation rate of shish I of cyclic, linear polyethylenes and their blend as a function of crystallization temperature Tc by means of polarizing optical microscope. We prepared the blend sample (C/L-PE) of cyclic polyethylene (C-PE with Mw=43600 as a matrix) and linear polyethylene (L-PE with Mw=65000, 3 wt%). As the results, we found that C-PE also forms shish-kebab structure from the sheared melt and I of C-PE with Mw=115000 is smaller than that of L-PE with Mw=65000. Whereas, we could not observe the formation of shish for C-PE homopolymer with Mw=43600. We found that Tc of C/L-PE is higher than that of C-PE with Mw=115000 and I of C/L-PE is close to L-PE homopolymer. |
