Isomerization polymerization cationic

Kennedy, J. P. and Johnston, J. E. The Cationic Isomerization Polymerization of 3-Methyl-1-butene and 4-Methyl-l-pentene. Vol. 19, pp. 57—95. 

Isomerization polymerizations can be associated with coordination catalyst systems, ionic catalyst systems, and free radical systems. The cationic isomerization polymerization of 4-methyl-1-pentene is of interest because the product can be viewed as an alternating copolymer of ethylene and isobutylene. This structure cannot be obtained by conventional... 

The Cationic Isomerization Polymerization of 3-Methy 1-1 -butene and 4-Methyl-l-pentene... 

This paper concerns the cationic isomerization polymerization of 3-methyl-1-butene and 4-methyl-1-pentene. Specifically, the microarchitecture (composition) of poly(3-methyl-l-butene) and poly(4-methyl-1-pentene) has been investigated, and the effect of synthesis conditions on polymer composition, polymer molecular weight and polymerization rate of 4-methyl-1-pentene has been studied. 

Previous work, (T-5) has shown that cationic isomerization polymerization of 3-methyl-1-butene produces a copolymer of two repeat units, the 1,2- i-CH2CH(iPrH-, and the 1,3- fCH2CH2C(CH3)2. Similarly, 4-methyl-l-pentene produces a terpolymer of 1,2-, 1,3-, and 1,4- -fCH2CH(iBu)-)-, -fCH2CH2CH(iPr)-f, and CH2CH2CH2C(CH3)2f, respectively. 

To predict the polymerization behavior of similar monomers on the basis of the knowledge generated with the 3-methyl-1-butene and 4-methyl-1-pentene systems, which in turn would yield novel copolymers via cationic isomerization polymerization. 

The cationic isomerization polymerization of 4-methyl- 1-pentene is similar to that of 3-methyl-1-butene as shown in Scheme 1 ... 

The results of the study of the effect of synthesis conditions on the composition of poly(4-methyl-l-pentene) have shown that even under conditions most favorable for the successful competition of isomerization with propagation, i.e., —120° C, using EtAlCl2, in ethyl chloride, the polymer contains only 50% of the desired 1,4-structure. It appears that in the series (n— l)-methyl-l-alkenes as n increases the likelihood of obtaining completely isomerized products via cationic isomerization polymerization is decreased. This is supported qualitatively by results obtained in the cationic polymerization of 4-methyl-l-hexene, an (n—2)-methyl-1-alkene (17). 

The detailed composition of poly(3-methyl-l-butene) and poly(4-methyl-l-pentene) produced by cationic polymerization has been investigated using high resolution 300 MHz H NMR and 20 MHz 13C NMR spectroscopy. It has been confirmed that both monomers polymerize by a cationic isomerization polymerization involving intramolecular hydride shifts. The composition of poly(3-methyl- 1-butene) obtained by cationic polymerization at — 130° C has been shown to be predominantly -(-CH2—CH2—C(CH3)2. ... 

P-Pinene which is a main component of natural turpentine can be polymerized by living cationic isomerization polymerization [82] (Scheme 10) using TiCl3(OfPr) as a Lewis acid in conjunction with rc-Bu4NCl in CH2C12 at -40 °C. When initiator 31 was used, polymerization led to a poly(P-pinene) macromonomer with a methacrylate function at the a end and a chlorine atom at the co chain end [83]. Three macromonomers were prepared with DPn=8,15, and 25 respectively they had narrow MWD (Mw/Mn= 1.13-1.22) and the reported functionality was close to 1 (Fn=0.90-0.96). 

Ferraris et al. contributed to the interpretation of cationic isomerization polymerization of 4-methyl-1-pentene [354], proposing the scheme, in which M = -CH,—CH -ch2CH(CH2)2... 

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