Copolymerization of the fungicidal chlorophenyl acrylates with methyl methacrylate

The four chlorophynyl acrylates, i.e., pentachlorophynyl acrylate(PCPA), 2,4,5-trichlorophynyl acrylate (2,4,5-TCPA), 2,4,6-trichlorophynyl acrylate (2,4,6-TCPA), and 4-chloro-3-methylphenyl acrylate (4-Cl-3-MPA) were synthesized in reasonable yield. The identification of these compounds were performed by the IR and NMR spectroscopy. Each of these chlorphenyl acrylates was copolymerized with methyl methacrylate (MMA), in benzene at 50๐C initiated byα, α’-azobisisobutyronitrile (AIBN). For each chlorophynyl acylate, various monomer feeding ratios, usually from 0.1 to 0.7 mole fraction of the chlorophynyl acrylate, were used. For low conversion, the copolymer composition of each copolymer was then determined by UV-Visible spectroscopy using the corresponding fungicidal homo-polymer as a standard. For high conversion, the residual monomer in each reaction was, instead, monitored by gas-liquid chromatography. Finally, the monomer reactivity ratios of each copolymer were determined by using two methods; Fineman-Ross and and Mayo-Lewis method. The first method gave r1 = 1.07+-0.04, r 2 = 0.08+-0.11 for MMA-2,4,5-PCPA; r1 = 0.84+-0.01, r2 = 0.36+-0.05 for MMA-2,4,6-TCPA; r1 = 0.58+-0.01, r2 = 0.20+-0.05 for MMA-2,4,6-TCPA; r1 = 0.67+-0.2, r2 = 0.33+-0.02 for MMA-4-Cl-3-MPA. Mayo-Lewis method yielded r1 = 1.00, r2 = 0.08 for MMA-PCPA; r1 = 0.92, r2 = 0.42 for MMA-2,4,5-TCPA; r1 = 0.63, r2 = 0.12 for MMA-2,4,6-TCPA and r1 = 0.64, r2 = 0.37 for MMA-4-Cl-3-MPA. The monomer reactivity ratios, as determined by both methods, are in reasonable agreement.