Copolymerization of the fungicidal chlorophenyl acrylates with vinyl acetate

Abstract

The four chlorophenyl acrylates; pentachlorophenyl acrylate (PCPA), 2,4,6-trichlorophenyl acrylate (2,4,6-TCPA), 2,4,5-trichlorophenyl acrylate (2,4,5-TCPA) and 4-chloro-3-methylphenyl acrylate (4-Cl-3-MPA), were synthesized with percentage yield of 87, 90, 92 and 85, respebtively. Their chemical structures were confirmed by spectroscopic iden-tification. The last three acrylates are the novel compounds as revealed by literature search. Each of these compounds was copolymerized with vinyl acetate (VAc) and with various monomer feeding ratios. Their homopolymers were prepared as well. The copolymer composition of each copolymer was then determined by UV-Visible spectroscopy usin.g the corresponding homopolymer as a standard. In addition, determination of copolymer composition of poly(2,4,5-TCPA-co-VAc) by 'H-NMR gave the same result as considered by UV-Visible spectroscopy. Particularly, both homopolymerization of 4-chloro-3-methylphenyl acrylate and its copolymerization with vinyl acetate exhibitXed the slowest rates of reactions. This indicated the chain transfer reaction had occurred during polymerization. Finally, the monomer reactivity ratios of each chlorophenyl acrylate with vinyl acetate were determined using linearization method derived by Fineman and Ross (1950). It revealed that for PCPA—Vac, r₁=2.18, r₂=0.02; for 2,4,6-TCPA—Vac, r₁=0.80, r₂=0.03; for 2,4,5-TCPA—Vac, r₁=0.981, r₂=0.035 and for 4-Cl-3-MPA—Vac, r₁=0.808, r₂=0.01.