Synthesis and Some Physico-Chemical Properties of Novel Starch-g-poly(citronellyl acrylate) Copolymers

Novel amphiphilic, more environmentally friendly starch graft copolymers obtained by applying the grafting from method are prepared. The graft copolymerization of various ratios of citronellyl acrylate monomer and potato starch at 80 degrees C in the presence of potassium persulfate (1wt.%) as an initiator is performed. The maximum of the grafting percent (%G) is observed for potato starch to monomer ratio 1:1.25 where ca. 1.8 hydroxyl groups per glycoside unit are covalently bonded with hydrophobic polymer chains. The graft materials are characterized by the attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), cross-polarization magic angle spinning (C-13 CP/MAS NMR), and scanning electron microscopy (SEM). The performed analyses affirm the structure of the graft materials and confirm the creation of non-porous copolymers with brief, heterogeneous surface. The selected physico-chemical properties of the obtained graft copolymers such as ability to gelation, moisture absorption, swelling in polar and non-polar solvents, chemical resistance, thermal properties, and pyrolysis mechanism are evaluated and compared with the previously tested starch-g-poly(citronellyl methacrylate) copolymers.