Synthesis of Poly(2-methyl-3-hydroxyoctanoate) via Anionic Polymerization of α-Methyl-β-pentyl-β-propiolactone

Abstract

Synthesis of an alpha,beta-alkyl branched polyester, i.e., poly(2-methyl-3-hydroxyoctanoate), has been accomplished via anionic polymerization of alpha-methyl-beta-pentyl-beta-propiolactone mediated by supramolecular complexes of potassium methoxide or potassium hydroxide, respectively. The structure of resulting polymers has been established by electrospray ionization multistage mass spectrometry (ESI-MSn), FT-IR, NMR, and GPC analyses. Previously proposed addition-elimination mechanism of the polymerization of beta-lactones containing alpha-hydrogen by alkoxide anion has been confirmed to operate also in the case of beta-lactone having alkyl substituents in both alpha and beta positions.

Ring-opening copolymerization of (R,S)-β-butyrolactone and ε-caprolactone using sodium hydride as initiator

“…Therefore, several attempts to use a catalyst based on much less toxic metal compounds are being undertaken [2,6,11,[22][23][24][25][26][27]. The anionic polymerization of β-butyrolactone had been widely studied [27][28][29][30][31][32][33][34][35][36][37][38][39][40], and in general polymers with low molecular weight were obtained. Relatively low toxic alkali metal hydrides are among the initiators used for this purpose [27], nevertheless, they have not been used so far for the synthesis of copolymers of (R,S)-BL and CL.…”

Controlled polymerization of α-methyl-β-pentyl-β-propiolactone by a discrete zinc alkoxide complex

“…MPP was prepared according to a literature procedure, 25 through cyclization of the appropriate b-hydroxy acid. LDA-mediated aldol condensation of commercially available propionic acid and hexanal gave the b-hydroxy acid, 3-hydroxy-2-methyloctanoic acid, in 97.6% yield after extraction and solvent evaporation.…”

“…† However, one group has reported the synthesis of poly(a-methyl-b-pentyl-bpropiolactone) (PMPP) from a-methyl-b-pentyl-b-propiolactone (MPP), a b-lactone obtained in two steps from propionic acid and hexanal (Scheme 2). 25 While the polymerization, initiated by crown ether/KOH or CH 3 OK complexes, proceeded only to oligomers in this case, we hypothesized that the material at a higher molecular weight could be used as an LLDPE substitute for PLA toughening. Although the properties of PMPP had not been investigated, we speculated that the glass transition temperature would be below room temperature, and the polyester backbone would be degradable.…”

“…In this report, we detail our synthesis of MPP according to the previously mentioned route, 25 and include additional information regarding product characterization, diasteromeric ratios, and monomer purification and stability. Additionally, we report the successful ring opening polymerization of MPP by a recently reported, high activity lactide polymerization catalyst, LZnOEt (LZ2,4-di-tertbutyl-6-{[(2 0 -dimethylaminoethyl)-methylamino]methyl}-phenol), 28 yielding an amorphous, high molecular weight polymer not readily available through microbial means.…”

Synthesis of Polylactide-b-Poly (Dimethyl Siloxane) Block Copolymers and Their Blends with Pure Polylactide

“…They offer attractive properties for biomedical, drug delivery, tissue engineering and packaging applications [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Among them, polylactide (PLA) possesses good barrier properties and excellent transparency.…”