Polymerization of cyclohexene oxide using yttrium isopropoxide and a bimetallic yttrium-aluminium isopropoxide as initiators

Abstract

SUMMARY: The polymerization of cyclohexene oxide (CHO) using yttrium isopropoxide and a bimetallic yttrium-aluminium isopropoxide initiation system is described. The reaction proceeds in bulk at room temperature leading to 70% yield in a few mins. High molecular weight polymers are obtained with a polydispersity index around 2. The polymerization in toluene solution is slower but leads to polymers with the same characteristics. Complete conversions can be obtained at low temperatures. NMR spectra of the resulting poly(cyclohexene oxide) revealed an atactic structure.

Synthesis, structural characterisation of new oligomeric alkyl aluminium (2,2′-methylene-p-chloro-bisphenoxides) and application as catalysts in polymerisation reactions involving cyclohexene oxide

“…4 typically shows the 13 C NMR spectrum for a poly(cyclohexene oxide) obtained after a ROP catalysed by an aluminium p-chloro-bisphenoxide. In a comparable manner, three main signals were found in 13 C NMR spectra for the methine carbons at 78.6, 78.0 and 76.6 ppm confirming the presence of several regions of different tacticity in the polymers [24]. The remaining methylene groups of the cyclohexane moieties belonging to the polymer backbone were found in two main groups ranging from 29.0 to 30.1 ppm and 23.4 and 22.2 ppm.…”

“…T.A. Zevaco et al / Journal of Organometallic Chemistry 692 (2007) 1963-1973 For compound 2 several 13 C NMR signals are found for the ethyl groups bound to the aluminium atoms, as expected at high-field, at 0.55 ppm, and 1.32 ppm for the methylene groups and 8.03, 8.58 and 9.87 for the methyl groups suggesting a structure in solution with different types of ethyl groups. In 1 H and 1 H-based 2D spectra of trinuclear 2 (COSY, gHMQC a.o.…”

“…Compared to other homogeneous aluminium-based catalytic system involving cyclohexene oxide as substrate like e.g. the multinuclear aluminium-yttrium isopropoxides of Spassky and Thiam [24] (M n 23 800-37 000, PDI 2.11-2.83, CHO/ Catalyst from 250 up to 550), it can be noticed that the aluminium para-bisphenoxides are promising catalysts due to a significant better molecular weight distribution. To complete the data gained from the DSC, the stereochemistry of the isolated poly(1,2-cyclohexene oxide) was investigated with 1 H NMR spectroscopy according to the literature [25].…”

Influence of Catalyst and Polymerization Conditions on the Properties of 1,3‐Trimethylene Carbonate and ε‐Caprolactone Copolymers

“…[26] It appears from the results that not all of the potentially active groups of the yttrium isopropoxide added to the reaction mixture were available for initiation of the polymerization. [18,23,27] When the sequential polymerization of the monomers was done in reverse order (i.e., TMC was the first monomer to be polymerized; entry 6, Table 2) the conversion of CL was not complete, resulting in a polymer enriched in TMC. From GPC analysis it was noticed that the copolymer thus prepared exhibited a broad bimodal molecular-weight distribution (M w /M n ¼ 3.7).…”

Ring‐opening polymerization of cyclohexene oxide by recyclable scandium triflate in room temperature ionic liquid

“…Some catalysts for ROP of CHO have been reported. [10][11][12][13][14][15][16][17] So far, there is no report concerning the CHO polymerization by Sc(OTf) 3 18 and stored in argon after that volatile chemicals were completely removed in high vacuum at 60 C.…”