Aluminium and rare earths alkoxides as initiators for the heterogeneous anionic coordinated polymerisation of propylene oxide. A 1H NMR approach of the regioselectivity and transfer ability of the catalytic system

New Highly Functionalized Primary Allyl, Hydroxyl, and Tosyl Poly(propylene glycol)s (PPG) from Available PPG Derivatization

“…This terminal double bond, arising from a side reaction during the base-catalyzed polymerization of propylene glycol, leads to an allyl alcoholate species which can also react with propylene oxide (PO) to give CH 2 dCH-CH 2 -(OCH 2 CH(CH 3 )) n -OH chains. 3,14,15 Of note, these monohydroxylated species were not detected in the MALDI spectrum at 18 Da below the main series, but only seen with a very low intensity level in the m/z range 1300-1600 as previously reported. 3 From NMR intensities of allyl, hydroxyl, and polymer chain resonance protons, by assuming that all chains have either olefinic or alcohol end group, the polymerization degree of available PPG was calculated according to the following relation: DP ) 2h CH3(PG) /3(h all + h OH ), where h CH3(PG) , h all , and h OH are respectively the peaks integrations of β methyl (c), allyl (e), and hydroxyl (d) groups of polymer (Figure 3A).…”

“…Beside the signals of polymer chain and hydroxy ends, the spectrum showed also the characteristic peaks of allyl group at 3.9, 5.1, 5.2, and 5.8 ppm (Figure A). This terminal double bond, arising from a side reaction during the base-catalyzed polymerization of propylene glycol, leads to an allyl alcoholate species which can also react with propylene oxide (PO) to give CH 2 CH−CH 2 −(OCH 2 CH(CH 3 )) n −OH chains. ,, Of note, these monohydroxylated species were not detected in the MALDI spectrum at 18 Da below the main series, but only seen with a very low intensity level in the m / z range 1300−1600 as previously reported 3 300 MHz 1 H NMR spectra of (A) starting PPG 2000 in DMSO- d 6 , (B) PPG-diallyl in CDCl 3 for run 10, and (C) PPG-di(CH 2 ) 3 OH for run 14 in DMSO- d 6 .…”