Ultrasonic Solution Degradations of Polystyrene and Substituted Polystyrenes in Tetrahydrofuran as Solvent |
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| Authors: | S L Malhotra M Breton J M Gauthier |
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| Institution: | Xerox Research Centre of Canada Mississauga , Ontario, L5L 1J9, Canada |
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| Abstract: | Abstract Ultrasonic (70 W, 20 kHz) solution (2% THF) degradations of polystyrene (PS), poly(α-methylstyrene) (PαMeS), poly(p-isopropyl α-methylstyrene) (PpiPrαMeS), poly(p-chlorostyrene) (PpCIS), poly(p-bromostyrene) (PpBrS), and poly(p-methoxystyrene) (PpOMeS) have been carried out in tetrahydrofuran at 27° C. The average number of chain scissions S (where S = (M n)0/(M n)t] - 1), computed from the overall values of (M n)0 and (M n)t, were found to be different from those of S' (where S' = α((M n)0/(M n)t] - 1)) based on the component (only that part of the polymer which is involved in degradation) data of the weight fraction (α), (M n)0, and (M n)t), S' for polystyrene and substituted polystyrene follows the order PS gt; PpCIS gt; PpiPrαMeS gt; PpBrS gt; PpOMeS gt; PαMeS. In the case of PS where degradations were also carried out at -20°C, lowering of the temperature increased the weight fraction of polymer degraded as well as S. Based on the viscosity and GPC data, it is concluded that the ultrasonic solution degradation of PS does not lead to branched polymers. |
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