Nonisocyanate CO₂-Based Poly(ester-co-urethane)s with Tunable Performances: A Potential Alternative to Improve the Biodegradability of PBAT

Abstract

The objective of this study is to develop a nonisocyanate route to prepare a biodegradable CO 2 -based poly(ester-co-urethane) (PEU), which has some improved performances when compared with commercial poly(butylene adipate-co-terephthalate) (PBAT). These performances include mechanical properties, biodegradability, and melt processability. Specifically, five bis-alkylcarbamates were synthesized from diamines, methanol, and CO 2 . Subsequently, 1,4-butanediol (BDO) and dimethyl terephthalate (DMT) reacted with five kinds of CO 2 -based bisalkylcarbamates to study the influence of methylene group number on the performances of PEUs. Moreover, the effect of various ratios of aromatic to aliphatic blocks in PEUs on their properties was systematically investigated. Additionally, the hydrolytic stability of synthesized PEUs was evaluated upon the degradation percentage in phosphate-buffered saline. The semicrystalline PEUs with tunable properties exhibit an initial thermal decomposition temperature of over 273.7 °C and a T g above 12.4 °C. Due to the presence of hydrogen bonding, the tensile strength is as high as 49 MPa. The designed and synthesized PEUs are promising as a potential biodegradable thermoplastic with superior performances when compared with commercial PBAT.

New Kind of Thermoplastic Polyurea Elastomers Synthesized from CO2 and with Self-Healing Properties

“…Carbon dioxide (CO 2 ) is an abundant, inexpensive, and renewable carbon feedstock to replace fossil resources in manufacturing high-value chemicals − such as methanol, − cyclic carbonates, , urea derivatives, , and polymeric materials. − Therefore, the utilization and transformation of CO 2 as carbon–oxygen resource is currently attracting much attention in the field of sustainable and green chemistry. Especially, CO 2 can be used as a carbonyl building block to synthesize polymeric materials such as polycarbonates, − polyurethanes, − and polyureas. ,, Polyureas (PU) are important polymeric materials with versatile properties.…”

Recycling Polyurethanes through Transcarbamoylation

“…The obtention of O -dimethylcarbamates makes this strategy also very attractive since this intermediate is able to react with polyols to regenerate PUs using transcarbamoylation releasing MeOH. The reactivity of this intermediate also offers huge versatility in the outputs of this strategy since the mixture obtained from depolymerization can be used directly to regenerate new PUs through polycondensation or by modifying the formulation (e.g., by adding polyols) to rectify or confer new properties or performances to the regenerated PU . Alternatively, each constituent resulting from depolymerization can be isolated, particularly the O -dimethylcarbamates which due to their stability can be further reacted to synthesize new PUs (nonisocyanate routes) or converted to diisocyanates to be fed back into the classical PU industry to generate virgin PUs.…”

“…The reactivity of this intermediate also offers huge versatility in the outputs of this strategy since the mixture obtained from depolymerization can be used directly to regenerate new PUs through polyconden- sation or by modifying the formulation (e.g., by adding polyols) to rectify or confer new properties or performances to the regenerated PU. 49 Alternatively, each constituent resulting from depolymerization can be isolated, particularly the Odimethylcarbamates which due to their stability can be further reacted to synthesize new PUs (nonisocyanate routes) 49 or converted to diisocyanates to be fed back into the classical PU industry to generate virgin PUs. The last route is of interest in the case of the composition of PUs that is not suitable for the market or does not satisfy new regulations due to the presence of toxic substances (e.g., brominated flame retardant).…”

Soft, Formstable (Co)Polyester Blend Elastomers

“…Such polymer structure is typically realized in block-and multiblock copolymers, in which different block types or segments show low miscibility [3,4]. Various polyurethanes [5], especially poly(ester urethanes) (PEU) [6,7] and poly(ether urethanes), are thermoplastic elastomers, in which usually the polyurethane part forms the physical netpoints. High deformability of such poly-meric materials requires a high content of the amorphous phase with low T g , while the form stability demands stable physical interactions.…”