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| The feasibility of radical copolymerization of beta-pinene and acrylonitrile was clarified for the first time. The monomer reactivity ratios evaluated by Fineman-Ross method were r(Pin) = 0, r(AN) = 0.66 in dichloroethane at 60˚C with AIBN. The reactivity ratio data show that the copolymerization was a “simple alternating copolymerization”, yielding polymers rich in acrylonitrile units and randomly alternated by single beta-pinene unit. Furthermore, the possible controlled copolymerization of beta-pinene and acrylonitrile was then attempted via the reversible addition-fragmentation transfer (RAFT) technique. At a low beta-pinene/acrylonitrile feed ratio of 10/90 or 25/75, the copolymerization by using CPDB as the transfer agent displayed the typical features of “living” polymerization, such as first-order kinetics, a linear increase of the Mn with monomer conversions and low polydispersities (< 1.3). However, the “living” character could be observed only within certain overall monomer conversions. At higher overall conversions, the copolymerizations deviated from the living behavior probably due to the competitive degradative chain transfer of beta-pinene. |
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| Keywords:beta-Pinene; acrylonitrile; RAFT; copolymerization |
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