Polybutadiene at a glancetires,belts,hoses,Uses:gaskets,and sealsbutadieneMonomer:Ziegler-NattaPolymerization:polymerization,Morphology:amorphousGlass transition-106°Ctemperature:
Polybutadiene at a glance Uses: tires, belts, hoses, gaskets, and seals Monomer: butadiene Polymerization: Ziegler-Natta polymerization, Morphology: amorphous Glass transition temperature: -106 oC
4.4.2.1Ppolymerization-Free-radicalpolymerization:lowstereoregularity,little interest-Commercialpolymers:alkyllithium or Ziegler-Natta catalysts
▪Free-radical polymerization: low stereoregularity , little interest ▪Commercial polymers : alkyllithium or Ziegler-Natta catalysts. 4.4.2.1 polymerization
4.4.2.1polymerizationfour stereoregularforms:1.cis-1,4-polybutadiene,2. trans- 1,4-polybutadiene,3.isotactic 1,2-polybutadiene;4.syndiotactic1,2-polybutadiene
four stereoregular forms : 1.cis- 1,4-polybutadiene; 2. trans- 1,4-polybutadiene; 3. isotactic 1,2-polybutadiene; 4.syndiotactic 1,2-polybutadiene. 4.4.2.1 polymerization
4.4.2.1polymerization4.high resilience at lowdeformations-5.ozoneresistance(bothstatic and dynamic)-6.ability to accept higherlevels of filler and oil
▪4. high resilience at low deformations ▪5. ozone resistance( both static and dynamic) ▪6. ability to accept higher levels of filler and oil 4.4.2.1 polymerization
4.4.2.1polymerizationPolymer microstructure dependsstrongly on the ratio of monomer toorganolithium concentrationsConventional linear materialsareprepared at temperatures in the range24~40°C
▪Polymer microstructure depends strongly on the ratio of monomer to organolithium concentrations ▪Conventional linear materials are prepared at temperatures in the range 24~40ºC 4.4.2.1 polymerization