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ABSORPTION OF CO2 IN HIGH ACRYLONITRILE CONTENT COPOLYMERS: DEPENDENCE ON ACRYLONITRILE CONTENT. (R829555)
Citation:
Bortner, M. J., V. A. Bhanu, J. E. McGrath, AND D. G. Baird. ABSORPTION OF CO2 IN HIGH ACRYLONITRILE CONTENT COPOLYMERS: DEPENDENCE ON ACRYLONITRILE CONTENT. (R829555). 45(10):3413-3422, (2004).
Description:
In continuation of our goal to determine the ability of CO2 to plasticize acrylonitrile (AN) copolymers and facilitate melt processing at temperatures below the onset of thermal degradation, a systematic study has been performed to determine the influence of AN content on CO2 absorption and subsequent viscosity reduction. Our previous report focused on the absorption of CO2 in a relatively thermally stable 65 mol% AN copolymer. In this study, the ability for CO2 to absorb in AN copolymers containing 85–98 mol% acrylonitrile was determined, and subsequent viscosity and equivalent processing temperature reductions were evaluated. Eighty five and 90 mol% acrylonitrile/methyl acrylate (AN/MA) copolymers were found to absorb up to 5.6 and 3.0 wt% CO2, corresponding to reductions of Tg of 37 and 27 °C, and subsequent viscosity reductions of 61 and 56%, respectively. CO2 absorption in these copolymers was found to occur immediately, in contrast to the time dependent absorption observed in the 65 mol% copolymer. An Arrhenius scaling analysis was used to determine the equivalent reductions in processing temperature resulting from the viscosity reductions, and reductions of up to 25 and 9 °C were observed for the 85 and 90 mol% AN copolymers. Based on the specific conditions used for absorption, no significant CO2 uptake was observed for AN copolymers containing greater than 90 mol% acrylonitrile. Higher temperatures than those used here may be required to absorb CO2 into AN copolymers containing greater than 90 mol% AN.
Author Keywords: Author Keywords: Carbon dioxide; Acrylonitrile; Plasticizer