Synthesis and characterization of poly(lactic acid) based graft copolymers

Sulfuric acid and Amberlyst-H+ catalyzed condensation reactions of renewable keto acids with paraformaldehyde: synthesis of a new dispiro bis-lactone ring system 2,9,13-trioxadispiro[4.1.4.3]tetradecane-3,6,10-trione

The acid catalyzed condensation of levulinic acid with paraformaldehyde at 80 °C gives 2,9,11,14-tetraoxadispiro[4.1.5.3]pentadecane-3,6-dione, in which the structure was confirmed by X-ray crystallography.

Poly(lactic acid) based hydrogels

Polylactide (PLA) and its copolymers are hydrophobic polyesters used for biomedical applications. Hydrogel medicinal implants have been used as drug delivery vehicles and scaffolds for tissue engineering, tissue augmentation and more. Since lactides are non-functional, they are copolymerized with hydrophilic monomers or conjugated to a hydrophilic moiety to form hydrogels. Copolymers of lactic and glycolic acids with poly(ethylene glycol) (PEG) provide thermo-responsive hydrogels. Physical crosslinking mechanisms of PEG-PLA or PLA-polysaccharides include: lactic acid segment hydrophobic interactions, stereocomplexation of D and L-lactic acid segments, ionic interactions, and chemical bond formation by radical or photo crosslinking. These hydrogels may also be tailored as stimulus responsive (pH, photo, or redox). PLA and its copolymers have also been polymerized to include urethane bonds to fabricate shape memory hydrogels. This review focuses on the synthesis, characterization, and applications of PLA containing hydrogels.

Fully biobased thermoplastic elastomers: synthesis and characterization of poly(l-lactide)-b-polymyrcene-b-poly(l-lactide) triblock copolymers

Fully biobased thermoplastic elastomers poly(l-lactide)-b-polymyrcene-b-poly(l-lactide) triblock copolymers with PLLA as hard block and polymyrcene as soft block were synthesized and evaluated.