Synthesis of end-capped polyester from SmI2-catalyzed Tishchenko-type polyaddition of dialdehydes

✍ Scribed by Isao Yamaguchi; Takahiro Kimishima; Kohtaro Osakada; Takakazu Yamamoto

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 159 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199710)35:14<2821::aid-pola2>3.0.co;2-t

✦ Synopsis

SmI 2 -catalyzed polyaddition of 1,12-dodecanedial followed by treatment with benzaldehyde gives a polyester (1) containing three structural units, [OCH 2 -(CH 2 ) 10 -CH 2 O], [OCH 2 -(CH 2 ) 10 -CO], and [CO-(CH 2 ) 10 -CO], in the main chain and an OCH 2 Ph end-capping group. GPC analysis of 1 shows molecular weights of M n Å 5.5 1 10 3 and M w Å 14 1 10 3 . The 1 H-NMR spectrum reveals the polymer structure with the COOCH 2 Ph end group as well as the M n value (2.6 1 10 3 ) calculated based on an amount of the end-capping group and lower than that estimated from GPC. Mixtures of terephthalaldehyde and 1,12-dodecanedial in several molar ratios undergo similar polyaddition catalyzed by SmI 2 to give the corresponding copolyesters after treatment with benzaldehyde. Increase in the ratio of 1,12-dodecanedial causes increase in yield and molecular weight of the copolymer. Terephthalaldehyde shows a tendency to give alcohol-side {O{R{O{ unit in the polyester, whereas 1,12-dodecanedial is mostly incorporated as the acid-side {CO{R{CO{ unit. Terminal aldehyde group derived from dodecanedial is capped effectively by benzaldehyde to give the COOCH 2 Ph end group.