Effect of LiClO4 on the radical polymerization of Di-2-[2-(2-methoxyethoxy)ethoxy]ethyl itaconate

✍ Scribed by Hiroyuki Nakamura; Makiko Seno; Tsuneyuki Sato

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 247 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19970115)35:1<153::aid-pola16>3.0.co;2-j

✦ Synopsis

The effect of LiClO 4 on the polymerization of di-2-[2-(2-methoxyethoxy)ethoxy]ethyl itaconate (DMEI) with dimethyl 2,2-azobisisobutyrate (MAIB) was investigated in methyl ethyl ketone (MEK) kinetically and by ESR. The polymerization rate (R p ) at 50ЊC, where the concentrations of DMEI and MAIB were 1.00 and 5.00 1 10 02 mol/L, increased with increasing [LiClO 4 ]. Marked acceleration was observed at higher [LiClO 4 ]s than 1.0 mol/L. The molecular weight of resulting polymer (ca. 10,000) was relatively insensitive to [LiClO 4 ], indicating occurrence of chain transfer. IR analysis of mixtures of LiClO 4 /DMEI and LiClO 4 /poly(DMEI) indicated complexation of LiClO 4 with DMEI and its polymer. The rate constants of propagation (k p ) and termination (k t ) were determined by ESR. k p (1.7-10.5 L/mol s at 50ЊC) increased with [LiClO 4 ]. k t (5.2-1.0 1 10 4 L/mol s at 50ЊC) showed remarkable decrease at higher [LiClO 4 ]s than 1.0 mol/L. R p of polymerization of equimolar complex of LiClO 4 /DMEI with MAIB at 50ЊC in MEK was expressed by R p Å k[MAIB] 0.5 [DMEI] 2.4 . k p increased and k t decreased with [DMEI]. The activation energies of overall polymerization, propagation and termination were estimated to be 34.5, 8.0, and 59.4 kJ/mol. Copolymerization of DMEI with styrene was also profoundly affected by the presence of LiClO 4 . Such large effects of LiClO 4 on the homo-and copolymerization of DMEI are explicable in term of association of LiClO 4 -complexed DMEI monomers.