Functionality of Telechelic Diene Polymers

x and y stand for the weight fraction of 1,2 and 1,4 units, respectively. On the other hand, commercial hydroxy-telechelic polybutadiene obtained by radical 

The functionality of hydroxy-telechelic polybutadiene and polyisoprene was determined by -NMR after modification with phenyl isocyanate or naphthyl isocyanate. Liquid telechelic polybutadiene and polyisoprene, prepared by choosing appropriate reaction conditions, showed Fn value of about 1.9, which agreed with the values determined by titration method [69]. 

Amino-terminated telechelic polybutadiene was prepared by LiAlH4 reduction of amidino end-group in polybutadiene, which was polymerised by a water-soluble initiator, 2,2 -azobis(amidinopropane)dihydrochloride. The structure was analysed by 1H- and 13C-NMR, but functionality of 2.0 was obtained by a titration method [70]. Synthesis of co-epoxy-functionalised polyisoprene was carried out by the reaction of 2-bromoethyloxirane with living polymer that was initiated with sec-butyl lithium. The functionality of the resulting polyisoprene was 1.04 by 1H-NMR and 1.00 by thin layer chromatography detected with flame ionisation detection [71]. 

The terminal hydroxyl groups in hydroxy-telechelic polybutadiene are assumed to be predominantly primary alcohols linked to c/s-1,4, trans-1,4, and 1,2 butadiene units [72], Detailed structure of the butadiene or isoprene units at both terminals was studied by the use of 2H-NMR [73], as shown in Section 6.1 

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