Spring 2008 Chap 12 ZieglarNatta Catalyst Before ZN

Spring 2008 Chap 12. Zieglar-Natta Catalyst - Before Z-N Catalyst invention, PP composites were only atactic form - After that, isotactic PP composites of extraordinary MW(>106) is synthesized LDPE = HPPE HDPE This has less hardness, stiffness and strength compared to HDPE, but better ductility, Free radical Use chromium compounds. Zieglar-Natta process is recent application. A few number of branches Al. R 3, Al. HR 2 10 billion lb/yr PP Natta 4 billion lb/yr l. Characteristic conditions for PP PP and solid catalysts are put together at 50℃ to 90℃ below 5 atm. After stopping of reaction, it is washed with H 2 O or ROH to remove the catalysts. MW is on the control of chain transfer agent E. g. ) CO 2, H 2 O, … Hanyang Univ.

Spring 2008 Dr. Ziegler and Dr. Natta Both earned the Nobel Prize in 1963 !! Hanyang Univ.

Spring 2008 Zieglar-Natta Catalyst Monometallic Bimetallic mechanism Assumption: equal site reactivity - Monometallic Corsee mechanism Hanyang Univ.

Spring 2008 Zieglar-Natta Catalyst Bimetallic Ti. Cl α-Ti. Cl 3 β-Ti. Cl 3 2 vacancy sites => atactic 1 vacancy site => isotactic Hanyang Univ.

Spring 2008 Zieglar-Natta Catalyst This image shows the mechanism by which the Ziegler Natta catalyst polymerizes 1 -propene. The image was created by Christine Ann. Hanyang Univ.

Spring 2008 A Polymerization rate B C Time Types of rate curves observed in Ziegler-Natta polymerization: (A) constant; (B) decaying; and (C) decaying to constant Hanyang Univ.

Spring 2008 Polyethylene Polymerization A B E D C Hanyang Univ.

Spring 2008 Chap 13. Polymerization Processes Bulk polymerization v Homogeneous polymerization Solution Polymerization Suspension polymerization v Heterogeneous polymerization Emulsion polymerization Hanyang Univ.

Spring 2008 Bulk polymerization Hanyang Univ.

Spring 2008 Solution Polymerization Hanyang Univ.

Spring 2008 Suspension polymerization Hanyang Univ.

Spring 2008 Emulsion polymerization Hanyang Univ.

Spring 2008 Stages in Emulsion Polymerization Hanyang Univ.