Polymerization of .beta.-monosubstituted-.beta.-propiolactones using trialkylaluminum-water catalytic systems and polymer characterization

Abstract

The homopolymerization la was attempted with anionic (nbutyllithium), cationic (titanium tetrachloride), and radical (AIBN; benzoyl peroxide; benzoin methyl ether, hv) initiators. In each case, no polymer was obtained and the monomer was recovered.

Ring-opening polymerization of ?-caprolactone initiated by cyclopentadienyl sodium

“…It was demonstrated by Gross and colleagues 24 and Kricheldorf and Boettcher 25 that t-BuOk and n -butylLi can initiate anionic polymerization of lactide in toluene. They found that the polymerization of lactide reacted by the deprotonation of monomers [ eqs.…”

New promising biodegradable polyesters derived from poly((R,S)-3,3-dimethylmalic acid) for cardiovascular applications

“…13 C NMR spectroscopy was used in the literature to identify the stereoregularity of the polyester [111][112][113][114]. The carbonyl peak around 167 ppm is a particularly sensitive and effective signal which provides the [115][116][117].…”

Synthesis and degradation of polyesters

“…By using the characterisation methods DSC and 13 C NMR, the structure of the copolymers synthesized has been studied in detail. Some suggestions on the possible types of copolymers obtained (block, alternating or random) are made, based on the experimental results.…”

“…Tetramethylsilane (TMS) was used as internal reference. 13 C NMR measurements of 1±1.5 %(w/v) were recorded at 50.3 MHz on a Bruker WP 200 SX spectrometer with a total of 2000±4000 scans collected and a delay time of 0.5 s.…”

“…Thus, by studying the sequence distribution in the copolymers by 13 C NMR spectroscopy and then considering their reactivity ratios, it might be possible to obtain a better idea of the real structure of the synthesized copolymers.…”