| 초록 |
Controlled Rheology(CR) Polypropylene was made by reactive extrusion process with organic peroxide as radical initiator which can degrade PP molecule chains. Commonly, an organic peroxide leads to degradation of homo PP by β-scission. On the contrary, a peroxide attacks on PE leads to chain branching and cross linking. Consequently during reactive extrusion of impact polypropylene copolymers in the presence of peroxide, both mechanisms can affect. In this study, the influence of peroxide degradation on the rheological behavior, mechanical properties and crystallization of an impact polypropylene copolymer was characterized and the property between CR grade(CRPP) and Reactor grade(REPP) was compared. It has been observed that the viscous properties decreased with increase of peroxide concentration, moreover, stiffness, impact strength and elongation at break reduced. In the case of crystallization, both crystal spherulite density and crystal growth rate of CRPP are lower than REPP. |
