In-situ preparation and properties of bio-renewable acylated sodium alginate-g-polytetrahydrofuran/Ag-NPs nanocomposites

Biomass sodium alginate (SA) and biomass-derived ether tetrahydrofuran (THF) have drawn considerable attention due to their sustainability and bio-renewability. In this paper, the novel acylated sodium alginate- g -polytetrahydrofuran graft copolymers (ASA- g -PTHF) with various PTHF branches ( M n,PTHF  = 600–4800 g/mol, G N  = 3–20 per 1000 SA monosaccharide) could be successfully synthesized by combination of THF living cationic ring-opening polymerization with grafting-onto method. The microphase separation of ASA- g -PTHF graft copolymer formed via self-assembly from two kinds of segments in backbone and side chains and was emphasized by thermal annealing, leading to a remarkable increase in water contact angle on polymer surface even by 38.4°. The hydrophilicity and crystallization behavior of ASA- g -PTHF can be decreased with increasing M n,PTHF and G N , which confine the crystallization of graft copolymer. ASA- g -PTHF microspheres (~1 μm) loaded with ibuprofen shows pH sensitivity and reach 100% of drug-release at pH = 7.4 within 30 h. ASA- g -PTHF exhibits resistance to bovine serum albumin adsorption and its composite with small-scaled silver nanoparticles (Ag-NPs, <2.6 wt%, 5–15 nm) generated in - situ behaves good antibacterial performance against E. coli and S. aureus . The ASA- g -PTHF would contribute to the better utilization of biomass and has promising for biomedical applications.