Mechanism of dispersion polymerization of L -lactide initiated with 2,2-dibutyl-2-stanna-1,3-dioxepane

Cyclic polymers: Synthetic strategies and physical properties

“…For most REPs of these monomers, the small Bu 2 Sn containing cycles summarized in Scheme 49 served as initiators [208][209][210][211][212][213][214][215][216][217][218][219][220][221][222][223][224][225][226] above all the seven-membered dibutyl-2-stanna-1,3-dioxepane (DSDOP). [212][213][214][215][216][217][218][219][220] The first three examples presented in Scheme 49 were known from the work of several inorganic chemists for a long time, [165][166][167][168] but those authors did not use these heterocycles as initiators.…”

Polylactones, 53. Formation of Cyclic Polyesters in the Combined Ring-Expansion Polymerization/Ring-Opening Polycondensation of Lactones

“…These peaks were observable up to 10 000-14 000 Da (depending on the sample). From previous studies of poly(l-lactides) [22] it was known that the DHB catalyzed the hydrolysis of the polylactide chains and even cleaved these chains itself forming fragments with DHB endgroups. All these facts together raised the suspicion that at least a fraction of the 4X chains resulted from DHB mediated hydrolysis of cycles during the preparation of the irradiation targets.…”

Effect of the phenyl ring substituent on stereoselectivity in the ring-opening polymerization of the rac-lactide initiated by salen aluminum complexes

“…The stereo-composition of the polymers affects the physical and chemical properties of themselves. Usually, PLA is prepared by the ring-opening polymerization (ROP) of lactide initiated by metal complexes, such as some alkoxides of Sn [7], Al [8][9][10][11][12], Zn [13][14][15][16], Mg [17][18][19], Fe [20], Ti [21][22][23][24][25][26], In [27], rare earth metal [28][29][30][31][32][33], organo-catalytic system [34,35], and enzyme [36]. In addition, the ring-opening copolymerization of epoxides and cyclic anhydrides has also the potential to produce a wider variety of polymer backbone structures [37,38].…”