Regioregular Polymers from Biobased (R)-1,3-Butylene Carbonate

Abstract

We present (R)-1,3-butylene carbonate ( R-BC) as a biorenewable monomer for the preparation of semicrystalline aliphatic polycarbonates. This conversion is achieved by using enantiomerically pure, biobased (R)-(−)-1,3-butanediol (bio-BG) as a renewable feedstock. Ring-opening polymerization from select catalysts at low temperatures can yield regioregular poly­((R)-1,3-butylene carbonate) ( R-PBC) with semicrystalline properties (X reg = > 0.99; T m = 72 °C). Along with the R-enantiomeric polymer, the alternate stereochemical polymers (using S- and racemic BC) were investigated. Our analysis shows that the highest level of crystallinity is achieved with regioregular, biobased R -PBC compared to the petrol-based S- and racemic congeners. This work shows the potential of stereochemically pure bio-BG as a starting material for semicrystalline, aliphatic carbonates when high regioregularity is achieved in the polymer microstructure. The synthesis and thermal characterization of regioregular butylene carbonate polymers are described in detail.

Complexities of Regioselective Ring-Opening vs Transcarbonylation-Driven Structural Metamorphosis during Organocatalytic Polymerizations of Five-Membered Cyclic Carbonate Glucose Monomers

“…The two isomers of each unimer fraction were produced in differing proportions. For the MBGC unimers (10,11) and unimers derived from MCGC and MEGC (12−15), integration of 1 H signals that were distinguishable as belonging to either the 3-or 2-unimer indicated, consistently, ca. 70:30 differential concentrations of the two regioisomers for each unimer type.…”

“…Polymeric materials constructed from renewable resources are prominent candidates toward achieving sustainability goals for the plastics market − while also offering potential for rich chemical functionalities, stereochemical diversities, and regiochemical differentiation . The regiochemical connectivity between repeating units along the backbone is known to have substantial impacts on physical, chemical, , and mechanical properties. , Regiochemical differences may be introduced through polymer connectivities being installed at different polymerizable sites within a common substrate, via polymerization conducted on positional isomers, , or from directional polymer backbone connectivity (head-to-head, head-to-tail, tail-to-tail). − …”

Highly Reactive Cyclic Carbonates with a Fused Ring toward Functionalizable and Recyclable Polycarbonates

“…Aliphatic polycarbonates (APCs) have received considerable attention as promising biomaterials owing to their biocompatibility and degradability. − The introduction of functionality into polycarbonates offers the opportunity to create novel, high-performance materials for drug-delivery vehicles, imaging agents, and three-dimensional (3D) printing. ,, Ring-opening polymerization (ROP) of cyclic carbonates (CCs) has been exploited for the preparation of APCs because of its capability for high levels of control over polymer molecular weight, dispersity, and end-group fidelity. − Previous reports have mainly focused on six-membered ring cyclic carbonates (6CCs) since a variety of biosourced compounds such as glycerol, glucose, and amino acid derivatives could be employed as starting materials, and their synthetic route is well established. − It is believed that seven-membered ring cyclic carbonates (7CCs) are great candidates for ROP as well due to their strong ring strain, which will result in high reactivity. However, only a few 7CCs including the unsubstituted 7CC and functionalized analogues and N-substituted 8CCs have been applied for ROP due to their challenging synthesis. ,− …”

Stereocomplexation of Stereoregular Aliphatic Polyesters: Change from Amorphous to Semicrystalline Polymers with Single Stereocenter Inversion

“…In addition to cases where high tacticity or enantiopurity orders packing of polymer chains, such ordering can also occur upon co-crystallization and assembly of two enantiopure polymers with opposite chirality (stereocomplexation), with the resulting crystallinity reflected in an increase in the melting temperature ( T m ). ,, Stereocomplexation has been found to be a useful strategy for enhancing polymer thermal properties beyond those of its enantiopure constituents, with the effects being dependent on the structural attributes of the monomeric units. PLA-related polymers have been studied extensively for stereocomplexation, − and other examples include polymethylmethacrylates, − polycarbonates, ,− polyhydroxyalkanoates, − polysaccharides, and polycarbodiimides . Notwithstanding these advances, the number of polyester stereocomplexes is modest and much remains to be learned about the factors contributing to stereocomplexation. − …”