Poly isobutylene Backbone

The simplest method to obtain PIB backbone with pendant functionalities able to initiate polymerization of a second monomer is via copolymerization of IB with a functional monomer such as bromomethylstyrene (BMS) or chlorometh- 

All products were soluble in water, indicating the formation of the graft copolymer and the absence of ungrafted macroinitiator. Dialysis of the product also revealed the absence of low MW ( 6000 g mol-1) homo poly(2-methyl-2-oxazoline). Due to the amphiphilic nature of the graft copolymer, aggregation in water as well as in chloroform was shown by NMR spectroscopy, solution vis- 

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Wolter (1978) has claimed that the data presented in Tables 6.1 and 6.2 are capable of a more refined interpretation. He noted that the correlation between the UCFT and the 0 -temperature was excellent, irrespective of the molecular weight, for poly(oxyethylene) in aqueous 0 39 M MgS04 and poly(isobutylene) in 2-methylbutane. Both of these chains lack dipolar substituent groups attached to the backbone chain. An identical comment applies to the UCFT data presented in Table 6.8 for poly(dimethylsiloxane), which were unavailable to Wolter. Again, this is for a polymer lacking dipolar substituents. 

Better control of grafting and less homopolymer formation is achievable in ionic reactions than can be obtained in free-radical reactions. Anionic grafting via backbone initiation has been demonstrated (22) with caprolacteim on macromolecular ester sites of styrene/methyl methacrylate copolymers. Cationic grafting of isobutylene onto poly(vinyl chloride) with the aid of aluminum alkyl has been carried out by J. P. Kennedy (23). 

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