TY - JOUR
T1 - Synthesis of ethylene/propylene elastomers containing a terminal reactive group
T2 - The combination of metallocene catalysis and control chain transfer reaction
AU - Kandil, U.
AU - Chung, T. C.
PY - 2005/5/1
Y1 - 2005/5/1
N2 - This article discusses a chemical route to prepare new ethylene/propylene copolymers (EP) containing a terminal reactive group, such as φ-CH 3 and OH. The chemistry involves metallocene-mediated ethylene/propylene copolymerization in the presence of a consecutive chain transfer agent - a mixture of hydrogen and styrene derivatives carrying a CH 3 (p-MS) or a silane-protected OH (St-OSi). The major challenge is to find suitable reaction conditions that can simultaneously carry out effective ethylene/propylene copolymerization and incorporation of the styrenic molecule (St-f) at the polymer chain end, in other words, altering the St-f incorporation mode from copolymerization to chain transfer. A systematic study was conducted to examine several metallocene catalyst systems and reaction conditions. Both [(C 5Me 4)SiMe 2N( tBu)]TiCl 2 and rac-Et(Ind) 2ZrCl 2, under certain H 2 pressures, were found to be suitable catalyst systems to perform the combined task. A broad range of St-f terminated EP copolymers (EP-t-p-MS and EP-t-St-OH), with various compositions and molecular weights, have been prepared with polymer molecular weight inversely proportional to the molar ratio of [St-f]/[monomer].
AB - This article discusses a chemical route to prepare new ethylene/propylene copolymers (EP) containing a terminal reactive group, such as φ-CH 3 and OH. The chemistry involves metallocene-mediated ethylene/propylene copolymerization in the presence of a consecutive chain transfer agent - a mixture of hydrogen and styrene derivatives carrying a CH 3 (p-MS) or a silane-protected OH (St-OSi). The major challenge is to find suitable reaction conditions that can simultaneously carry out effective ethylene/propylene copolymerization and incorporation of the styrenic molecule (St-f) at the polymer chain end, in other words, altering the St-f incorporation mode from copolymerization to chain transfer. A systematic study was conducted to examine several metallocene catalyst systems and reaction conditions. Both [(C 5Me 4)SiMe 2N( tBu)]TiCl 2 and rac-Et(Ind) 2ZrCl 2, under certain H 2 pressures, were found to be suitable catalyst systems to perform the combined task. A broad range of St-f terminated EP copolymers (EP-t-p-MS and EP-t-St-OH), with various compositions and molecular weights, have been prepared with polymer molecular weight inversely proportional to the molar ratio of [St-f]/[monomer].
UR - http://www.scopus.com/inward/record.url?scp=19944370820&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=19944370820&partnerID=8YFLogxK
U2 - 10.1002/pola.20672
DO - 10.1002/pola.20672
M3 - Article
AN - SCOPUS:19944370820
SN - 0887-624X
VL - 43
SP - 1858
EP - 1872
JO - Journal of Polymer Science, Part A: Polymer Chemistry
JF - Journal of Polymer Science, Part A: Polymer Chemistry
IS - 9
ER -