G. Kwag
May 24, 2002
Citations
0
Influential Citations
53
Citations
Journal
Macromolecules
Abstract
Ultrahigh cis-polybutadiene is prepared in 1,3-butadiene polymerization by the Nd catalyst of Nd(neodecanoate)3 (ND)/AlEt2Cl/Al(iBu)3 in the rubber industry. However, the catalytic activity remains low, and the reason is unclear. According to our matrix-assisted laser desorption ionization time-of-flight (MALDI−TOF) mass spectroscopic study, ND is a mixture of various oligomeric and hydrated compounds. The hydrated oligomeric structure would mainly lower the catalytic activity. To design a better Nd catalyst, Nd(neodecanoate)3·(neodecanoic acid) (NDH) was designed to satisfy the requisite of anhydrous and monomeric structure. NDH was prepared through ligand-exhange method between neodymium acetate and neodecanoic acid in an organic medium. NDH was identified and characterized with infrared (IR), MALDI−TOF mass, and synchrotron X-ray absorption spectroscopies (XAS) and with computer simulations. Weakly bound neodecanoic acid with the carbonyl peak at ca. 1670 cm-1 and carboxylate anion coordinated to Nd at...