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

Abstract

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 °C in the presence of potassium persulfate (1 wt.%) 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 (13C 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.

UV Polymerization of Methacrylates—Preparation and Properties of Novel Copolymers

“…Methacrylate ester monomers (geranyl methacrylate and citronellyl methacrylate) were obtained in the process of esterification of methacryloyl chloride with one of the natural terpene alcohols (geraniol or citronellol) in the presence of trimethylamine according to the procedure described in [30][31][32][33]. Terpene methacrylate esters were used as monomers in the preparation of copolymers with the commercially available methyl methacrylate (MM) monomer.…”

“…Scheme 1 shows chemical formulae of terpene methacrylate monomers. Methacrylate monomers were obtained as colorless liquids with a yield of over 95% using the synthesis method described previously in [30][31][32][33]. The structure of monomers and their purity were confirmed by 1 HNMR, 13 CNMR, and FTIR and the data were previously presented in [34].…”

“…Among the terpene compounds, the polymerization of β-pinene, monomers derived from pinene and limonene, and the polymerization of pinene with styrene or acrylates have been investigated [21][22][23][24][25]. Moreover, researchers have described the polymerization of citronellol oxide obtained from citronellol, leading to the production of hyperbranched polymers [26][27][28], and the graft polymerization of methacrylate ester derivatives of citronellol, geraniol, or nerol with starch in order to obtain more environmentally friendly graft materials with modified physicochemical properties [29][30][31][32].…”

Thermal studies on the starch-g-copolymers prepared from two terpene acrylate monomers under oxidative conditions

“…Starch/lactic acid graft copolymers [20][21][22], maleated thermoplastic starch-gpolylactic acid [23], esterified maleic anhydride starch-gpolylactic acid [24], hydroxyethyl starch-grafted-polylactide [25], starch-g-poly(vinyl alcohol) [26], starch-gpoly(n-vinylimidazole) [27], carboxymethyl starch-gpoly(N-vinylimidazole) [28,29] copolymers have been precisely studied. In addition, the copolymers received from potato starch and aromatic type meth(acrylate) monomers [30][31][32][33][34][35][36] and more, environmentally-friendly starch-g-poly(citronellyl acrylate) [37] and starch-gpoly(citronellyl methacrylate) copolymers [38,39] under the free radical copolymerization have been presented.…”