Kinetic and ESR studies on radical copolymerization of p-tert-butoxystyrene and di-n-butyl maleate in benzene

✍ Scribed by Tsuneyuki Sato; Takashi Kitajima; Makiko Seno; Yukako Hayashi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 189 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980715)36:9<1449::aid-pola13>3.0.co;2-4

✦ Synopsis

The copolymerization of p-tert-butoxystyrene ( TBOSt ) ( M 1 ) and di-n -butyl maleate ( DBM ) ( M 2 ) with dimethyl 2,2 -azobisisobutyrate ( MAIB ) in benzene at 60ЊC was studied kinetically and by means of ESR spectroscopy. The monomer reactivity ratios were determined to be r 1 Å 2.3 and r 2 Å 0 by a curve-fitting method. The copolymerization system was found to involve ESR-observable propagating polymer radicals under practical copolymerization conditions. The apparent rate constants of propagation ( k p ) and termination ( k t ) at different feed compositions were determined by ESR. From the relationship of k p and f 1 (

) based on a penultimate model, the rate constants of five propagations of copolymerization were evaluated as follows; k 111 Å 140 L /mol s, k 211 Å 3.5 L /mol s, k 112 Å 61 L /mol s, k 212 Å 1.5 L /mol s, and k 121 Å 69 L /mol s. Thus, a pronounced penultimate effect was predicted in the copolymerization.