MONOMER REACTIVITY RATIOS OF STYRENE-4-VINYLPYRIDINE COPOLYMERS AT LOW AND HIGH CONVERSIONS
POLYMER, vol.34, no.1, pp.145-149, 1993 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 34 Issue: 1
- Publication Date: 1993
- Doi Number: 10.1016/0032-3861(93)90297-n
- Journal Name: POLYMER
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.145-149
- Middle East Technical University Affiliated: No
Abstract
Monomer reactivity ratios in free-radical copolymerization of styrene and 4-vinylpyridine monomers at 80-degrees-C in toluene solution under reduced pressure were determined for low and high conversions. Finemann-Ross, Kelen-Tudos, extended Kelen-Tudos and Mayo-Lewis methods were used for this purpose. The most reliable method was found to be the extended Kelen-Tudos method. By the use of this method, for conversions below 20%, monomer reactivity values of 0.700 +/- 0.005 and 0.335 +/- 0.001 were calculated for 4-vinylpyridine and styrene respectively. For conversions greater than 20%, these values were found to reduce to 0.538 +/- 0.004 and 0.277 +/- 0.001 respectively.