Vinyl ethers and epoxides photoinduced copolymerization with perfluoropolyalkylether monomers.

New perfluoropolyalkylether (PFPAE) monomers, chain extended with different alkyl groups and functionalized with vinyl ether or epoxide end-groups, were employed, together with trimethylolpropane trivinyl ether or trimethylolpropane triglycidyl ether, to produce fluorinated copolymers. The photoinduced cationic polymerization was investigated, and the PFPAE-based copolymer properties were thoroughly characterized. Interesting surface properties and two different values of refractive index were observed: thus, these fluorinated copolymers can be suitable materials for the manufacture of self-cleaning coatings and optical waveguides.

Diels-Alder-Chitosan based dissociative covalent adaptable networks.

For the first time, Diels-Alder and retro Diels-Alder reactions were evidenced by 1H NMR spectroscopy and DSC on chitosan based systems. At first, preliminary studies led to structural identification and better understanding of the Diels-Alder reaction. Then, chitosan of 30,000 g/mol and 150,000 g/mol were modified by furfuryl glycidyl ether with 20% substitution degree. The resulting products were cross-linked with bis and trismaleimide crosslinkers to produce films possessing interesting mechanical properties. Unprecedented for chitosan-based films, DMA measurement highlighted retro Diels-Alder between 110 and 130 °C. Films showed interesting hydrophobicity and fat absorption. They also exhibited resistance in acidic media whereas crude chitosan films were dissolved.

Correction: Synthesis of α,ß-unsaturated esters of perfluoropolyalkylethers (PFPAEs) based on hexafluoropropylene oxide units for photopolymerization.

[This corrects the article DOI: 10.1039/C8RA06354K.].

Synthesis of α,ß-unsaturated esters of perfluoropolyalkylethers (PFPAEs) based on hexafluoropropylene oxide units for photopolymerization.

α,ß-unsaturated esters are usually synthesized for polymer applications. However, the addition of maleate (cis-configuration) to a fluorinated moiety is challenging due to its potential isomerization during esterification. Various synthetic routes were attempted and led to very low conversion or side-products. The immiscibility of both reagents combined with an easy isomerization or attack on the double bond were potential explanations. In this paper, the synthesis of maleates oligo(hexafluoropropylene oxide) is reported by Steglich esterification and the reaction conditions are discussed depending on the molecular weight of the fluorinated moieties. After UV-curing, hydrophobic polymers were obtained by copolymerization with vinyl ethers by electron acceptor-donor systems.