Copolymerization of carbon monoxide and norbornene derivatives with ester groups by palladium catalyst

✍ Scribed by Der-Jang Liaw; Jang-Shiang Tsai; Hui-Chuan Sang

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 144 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199808)36:11<1785::aid-pola12>3.0.co;2-a

✦ Synopsis

In this article we will discuss the synthesis of the new copolymers of norbornene derivatives with an ester group and carbon monoxide, using Pd(CH 3 CN) 4 (BF 4 ) 2 as a catalyst and 2,2 -bipyridine as a ligand in nitromethane/methanol at 60ЊC. Elementary analysis, infrared spectra, and NMR spectra indicated that copolymers contain ketone, ester, and bicyclic structures. Methanol functions as the coinitiator and chain transfer agent in copolymerization. A decrease in the molar ratio of [CH 3 OH]/[Pd] caused an increase in molecular weight and a decrease in yield of the copolymer. The number-average molecular weight of copolymers ( M n ) ranged from 3800 to 5300, and the glass transition temperature ( T g ) ranged from 032 to 117ЊC. Thermal analysis revealed that both T 10% d and T max d exceeded 180 and 230ЊC, respectively. Linear longchain substituents such as n-C 11 H 23 C(O){O{CH 2 { drastically reduced T g to a value of 032ЊC. In general, copolymers having a longer linear side-chain substituents of ester on norbornene have a more desirable solubility. Moreover, X-ray diffraction demonstrated that the degree of crystallinity decreases with an increasing length of side chain substituents.