Indexed by:期刊论文

Date of Publication:2009-07-28

Journal:MACROMOLECULES

Included Journals:EI、SCIE、Scopus

Volume:42

Issue:14

Page Number:5073-5079

ISSN No.:0024-9297

Abstract:A series of dendrigraft star-comb polybutadienes (PBs), from generation zero to four (G0-G4), were synthesized by anionic polymerization and grafting-onto methodology. The 4-arm star PB (GO PB) with high 1,4-content and narrow molecular weight distribution (MWD) was selectively epoxidized at the 1,4-PB sites to introduce grafting sites randomly along the polymer arms. The G1 PB was prepared by grafting of the epoxidized GO PB with polybutadienyllithium (PBLi) anions. The dendrigraft star-comb PBs of higher generations (G2, G3, and G4) were synthesized by repeating the epoxidation and grafting reaction cycles. The dendrigraft star-comb PBs had high molecular weights (M(w) = 8.3 x 10(3) -1.4 x 10(7)) and narrow MWDs (M(w)/M(n) = 1.01-1.20). Moreover, the molecular weight and branching functionality increased geometrically for the successive generations. The solution properties and the characteristic parameters ([eta], R(g), R(h) and g') of the dendrigraft star-comb PBs were determined and compared with those of the corresponding linear PBs. All results pointed to a much higher compactness of the dendrigraft star-comb macromolecular structure.