Stereoselective Ring-Opening (Co)polymerization of β-Butyrolactone and ε-Decalactone Using an Yttrium Bis(phenolate) Catalytic System

Abstract

An effective route for ring-opening copolymerization of β-butyrolactone (BBL) with ε-decalactone (ε-DL) is reported. Microstructures of the block copolymers characterized by 13 C NMR spectroscopy revealed syndiotactic-enriched poly(3-hydroxybutyrate) (PHB) blocks. Several di- and triblock copolymers (PDL- b -PHB and PDL- b -PHB- b -PDL, respectively) were successfully synthesized by sequential addition of the monomers using (salan)Y(III) complexes as catalysts. The results from MALDI-ToF mass spectrometry confirmed the presence of the copolymers. Moreover, thermal properties of the block copolymers were also investigated and showed that the microphase separation of PDL- b -PHB copolymers into PHB- and PDL-rich domains has an impact on the glass transition temperatures of both blocks.

Tacticity Characterization of Biosynthesized Polyhydroxyalkanoates Containing (S)- and (R)-3-Hydroxy-2-Methylpropionate Units

“…The tacticity of the P(3H2MP) homopolymers was further studied via 125 MHz 13 C NMR spectroscopy (Figure ). The expansion resonances for the methyl (∼14 ppm), methine (∼40 ppm), and carbonyl (∼174 ppm) regions were assigned at the diad and triad levels, corresponding to the GC-MS data and related studies. , Sample 3-S, with a 99 mol % ( S )-enantiomer fraction (98% ee ), revealed extremely high meso -diad ( m ) or isotactic-triad sequences ( mm ) at each resonance expansion (Figure B). For Samples 3-R and 3-RS, the NMR resonance showed a similar pattern except for the ratio between each diad and triad sequence.…”

Controlling polymer stereochemistry in ring-opening polymerization: a decade of advances shaping the future of biodegradable polyesters

“…The possibilities opened by lactones copolymerization in terms of materials properties modulation were recently explored by Venditto et al 82 Taking advantage of the remarkable reactivity of (salan)Y(III) complexes (30-Y), they reported an efficient route for the ring-opening copolymerization of β-butyrolactone (BBL) with ɛ-decalactone (ɛ-DL). By this way, several di-and triblock copolymers were successfully synthesized by sequential addition of the monomers (Scheme 7).…”

Recent Developments in Lactone Monomers and Polymer Synthesis and Application

“…Unfortunately, it has poor mechanical properties due to its fragility and tendency toward thermal degradation. Bioresorbable applications use block copolymers of β-butyrolactone as the soft segment and ε-caprolactone, lactide (LA) or ε-decalactone as the segment improving mechanical and thermal properties [41][42][43][44]. Copolymerization of β-butyrolactone with β-malolactone allows the obtaining of structures with biologically active centres [45].…”