Phase Transfer Catalyzed Polymerization of Styrene and Graft Copolymerization of Styrene onto Gelatin

Abstract

The use of tetrabutylammonium bromide (TBAB), as phase transfer catalyst during polymerization of styrene in the presence of water-soluble radical initiator, potassium persulfate (KPS), and graft copolymerization of styrene onto gelatin, a water soluble polymer, using a water-insoluble radical initiator, benzoyl peroxide (BPO), has been explored in a water-benzene biphasic system. The percentage conversion (Pc) of styrene to polystyrene and percent grafting (Pg) of styrene onto gelatin was studied as a function of various reaction parameters. Under optimum reaction conditions, maximum Pc (76%) was obtained at [KPS] = 12.9 × 10−4 moles/L, [Sty] = 4.3 ×10−3 moles/L, and maximum Pg (87%) was obtained at [BPO] = 4.6× 10−4 moles/L, [Sty] = 13.88 × 10−3 moles/L using [PTC] = 2.89 × 10−4 moles/Lin 10 mL each of water and benzene in 120 min at 60 °C. The graft copolymer, Gel-g-poly(Sty), was characterized by IR, Thermogravimetric Analysis, Scanning Electron Microscopy and swelling behaviour in different solvents. Metal uptake and degradation studies of the grafted sample were also carried out. The grafted sample showed maximum uptake for Cu2+ (88%), Ni2+ (80%) and Fe2+ (50%). Degradation studies of Gel-g-poly(Sty) were carried out by soil burial test and UV radiations. Photo-degradation showed better degradation (5.26% wt. loss) in 32 h of exposure to UV radiations as compared to soil burial degradation (8.46% wt. loss) in 30 days. Gelatin-styrene graft copolymers can thus be used as bio- and photo-degradable materials for environmental management.