| 초록 |
In order to investigate the effects of long chain branch (LCB) on melt fractures of mLLDPE, we prepared a sparsely long chain branched mLLDPE, mLLDPE without LCB and their blends. The blends thus prepared are considered to contain well defined amounts of the LCB. By thermal and rheological analysis ofthe blends, it was confirmed that the blends are miscible and the LCBs are homogeneously distributed. Gross melt fractures (GMF) were observed to decrease as the degree of LCB increases as expected. However, sharkskin melt fractures were found to increase with the degree of the LCB. There have been debates on the effect of the LCB on the SMF. Majority of research groups believe that the SMF decreases with the degree of the LCB. This study clearly showed that the SMF becomes severe with the increase of LCB density, and suggested that there may be another mechanism on the SMF. |
