Synthesis and Characterization of Functional Copolymers of Citronellol with Butylmethacrylate Initiated by Benzoyl Peroxide

摘要

Benzoyl peroxide (BPO)-initiated free radical copolymerization of citronellol with butylmethacrylate (BMA) in xylene at 80 C 0.1 C under the inert atmosphere of nitrogen has been studied. The kinetics expression is Rp a [I]~(0.5±0.27) [citronellol]~(1.0±0.13) [BMA]~(1.0±0.18). The overall activation energy has been calculated as 65 kJ/mol. Bands at 3436 and 1732 cm 1 in the FTIR spectrum of the copolymer(s) have indicated the presence of hydroxy, ester group of citronellol and butylmethacrylate, respectively. The 1H-NMR spectrum shows peaks at 7.0_7.7 d due to AOH proton of citronellol and at 3.2_4.0 d due to AOCH2 proton of butylmethacrylate. The molecular weight Mv and gint of the copolymers have been measured with the help of gel permeation chromatography in tetrahydrofuran at 25 C to calculate Mark-Houwink constants as K _ 2.68 10 4 and a _ 0.34 0.40. The alternating nature of the copolymer is confirmed by reactivity ratios r1 (BMA) _ 0.023 0.004 and r2 (Citronellol) _ 0.0025 0.22. The Alfrey-Price Q-e parameters for citronellol have been calculated as Q2 _ 0.13 and e2 _ _1.28. Thermal decompositions of copolymer are evaluated with the help of thermal gravimetric analysis technique. The mechanism of copolymerization has been elucidated.