Synthesis of Fluorine‐Containing, UV‐Responsive PLA‐Based Materials by Means of Functionalized DOX Monomer

Abstract

1,3‐Dioxolan‐4‐ones (DOX) chemistry is exploited for the synthesis of UV‐curable, polylactic acid (PLA)‐based copolymers. DOX monomer functionalized with 4‐fluoro‐4′‐hydroxybenzophenone is synthesized and employed as comonomer with l‐lactide. Copolymerization reactions are performed with different DOX loadings through a solvent‐free, metal‐catalyzed protocol. Products are characterized through NMR analysis in order to demonstrate the random insertion of the modified monomer within the polymeric chain. Copolymers are subjected to UV irradiation and compared to a control PLA synthesized and processed in the same conditions. The evolution of the molecular weight during prolonged UV exposure is evaluated through SEC analysis, showing the effect of the benzophenone side groups, which promote crosslinking reactions. A crosslinking mechanism is proposed and demonstrated by means of 1H NMR and FT‐IR analyses. The gel content of the samples is measured after the UV exposure, demonstrating a correlation with the concentration of DOX‐derived units. Finally, water contact angle analyses are performed to investigate the effects of the fluorination degree on the wettability properties and thermal characterization is carried out. Moreover, rheological analyses show a shear thickening behavior for the copolymers with the highest concentration of DOX‐derived units.

Hemiacetal Esters: Synthesis, Properties, and Applications of a Versatile Functional Group

“…Ring-opening polymerization can also be performed from five-membered ring monomers such as 1,3-dioxolan-4-ones (DOLOs). 37,38,91 These biobased and inexpensive monomers are prepared from the reaction between ketones or aldehydes with α-hydroxy acids (such as lactic or mandelic acids). Homopolymerization and copolymerization with cyclic esters (e.g., ε-caprolactone or β-butyrolactone) were reported to follow a ring-opening mechanism leading to the formation of polyesters and the release of formaldehyde or acetone in the presence of salen, DBU, TBD, or ZnEt 2 catalysts.…”

“…Ring-opening polymerization can also be performed from five-membered ring monomers such as 1,3-dioxolan-4-ones (DOLOs). ,, These biobased and inexpensive monomers are prepared from the reaction between ketones or aldehydes with α-hydroxy acids (such as lactic or mandelic acids). Homopolymerization and copolymerization with cyclic esters (e.g., ε-caprolactone or β-butyrolactone) were reported to follow a ring-opening mechanism leading to the formation of polyesters and the release of formaldehyde or acetone in the presence of salen, DBU, TBD, or ZnEt 2 catalysts. , Regarding homopolymerization, the salen-catalyzed reaction led to the formation of an isotactic biodegradable polyester, which had so far been synthesized only through a very expensive and toxic process (ROP of O -carboxy anhydrides using stoichiometric amounts of phosgene) .…”

Poly(alditol sebacate)-PLA copolymers: enhanced degradability and tunable surface properties

“…30,31 To overcome such drawbacks, our previous works pointed out the possibility to introduce appropriate side groups through copolymerization reactions between lactide and 1,3-dioxolan-4-ones (DOX) monomers. [32][33][34] On a general level, copolymerization reactions can be exploited in several different ways to improve the properties of a material or a class of materials [35][36][37][38][39] and within this perspective, and with the idea of developing fully biobased and biodegradable materials, mannitol was investigated as a possible comonomer for the synthesis of PLA-based polyesters with tunable properties and degradability. Mannitol, dulcitol and alditol in general are biobased carbohydrates that have often been employed as monomers for the synthesis of functional polyesters.…”