Tailored norbornene-based copolymer with systematic variation of norbornadiene as a crosslinker obtained via ROMP with alternative amine Ru catalysts

Author(s)

Carvalho, Jr., Valdemiro P. ^[1] ; Ferraz, Camila P. ^[1] ; Lima-Neto, Benedito S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: EUROPEAN POLYMER JOURNAL; v. 48, n. 2, p. 341-349, FEB 2012.
• Web of Science Citations: 21

Abstract

Copolymers of norbornene (NBE) with norbomadiene (NBD) were obtained via ROMP with {[}RuCl2(PPh3)(2)(L)] type complexes as initiators (1 for L = piperidine and 2 for L = 3,5-Me(2)piperidine). The reactions were performed using a fixed quantity of NBE (5000 equivalents/{[}Ru]) for different concentrations of NBD (500, 1000, 1500 and 2000 equivalents/ {[}Ru]) in CHCl3, initiated with ethyl diazoacetate at room temperature. The presence of NBD in the NBE chains was characterized by H-1 and C-13 NMR. Whereas the copolymer microstructure was influenced neither by the NBD quantity nor by the initiator type, the N-n and PDI values were improved when increasing the NBD quantity in the medium. When raising the NBD amount, DMA results indicated increased cross-linking with increasing T-g and E ` storage modulus, as well as the fact that SEM micrographs indicated decreased pore sizes in the porous isolated copolymers. (C) 2011 Elsevier Ltd. All rights reserved. (AU)