246. PAMAM dendron-grafted poly(vinyl alcohol) via click reaction

Franco Antonio-Antonio, Norberto Farfán, Rosa Santillan, Ma Eugenia Ochoa, Miguel C. Gutiérrez, Claudia Cecilia Rivera-Vallejo and Delia Soto-Castro; Materials Chemistry and Physics; (2021); DOI: 10.1016/j.matchemphys.2021.125215

Poly(vinyl alcohol) (PVA) is a linear polymer of synthetic origin, biocompatible and inert, representing a good starting point to incorporate dendrons and potentiate their ability to act as drug-carrier releasers. This article reports the synthesis of G 1.5 PAMAM-type dendrons from propargylamine with methyl or tert-butyl ester end groups. Subsequently, these dendrons were grafted into PVA functionalized with azide groups (N3) through a click reaction. Dendron-grafted PVA showed different chemical and physical properties to those of PVA and azidated PVA, since PAMAM-type dendrons modified the molecular interactions between the different polymer chains and with the medium, resulting in changes in hydrodynamic radius (Rh) density, solubility, and glass transition temperature. Compared with PVA and azidated PVA, the grafting of methyl ester ended dendrons afforded a 94% water-soluble material at room temperature, with a decrease in its density and an increase in its Tg, while in the case of the tert-butyl ester ended dendrons only 69% of the material is water-soluble, and it presented the lowest density and the lowest Tg due to increasing in free volume. The Rh values of dendron-grafted PVA increased according to molecular weight. The obtained products were characterized by ATR-FTIR, UVvis, and/or NMR (1H, 13C).