Polydienes terminally functional

Amination. The synthesis of polymers with primary amine end-group functionality has been a challenge because the primary amine group can undergo rapid chain transfer and termination reactions with car-banionic chain ends (14). Schulz and Halasa (15) used a phenyllith-ium initiator with a bis(trimethylsilyl)-protected amine group to prepare amine-terminated polydienes. Nakahama and coworkers (16,17)... 

These results indicate that if polydienes and similar polymers can be prepared quantitatively with tertiary amine terminal groups, then they can be combined with other halogen functional polymers using established techniques to create interesting new block copolymer systems. For example, consider the reaction between telechelic pyridine terminated polybutadiene and monofunctional bromine terminated polystyrene (equation 4) -the latter has been prepared in 95% yield. >it The product would be an ABA... 

Synthesis of functional Terminal Polymers. Mono-and di- terminal -OH and - polydienes were prepared according to our published procedures (13.14). Star -OH polydienes were synthesized analogously except that ethyl 6-1ithiohexyl acetaldehyde acetal was used as the initiator and trichloromethylsilane as the joining agent. 

The x,x -azobis(x-cyano-alkanol)s are prepared by the Strecker synthesis followed by oxidation of the hydrazo intermediate. The same method was also used for 4,4 -azobis(4-cyano-n-pentanol) and 5,5 -azobis(5-cyanohexane-2-ol). The former one was a good initiator for secondary hydroxyl-terminated polydienes. Similar results were reported by Reed (see Sect. 1.1.2. a) for hydroxytelechelic polybutadienes (the functionality was 1.9 to 2.5, generally higher than 2, M < 5000). 

Another group of block copolymers which has been studied is that of poly (e-caprolactam)-iilock-polydiene elastomers. Originally (see Ref [52]), hydroxy-terminated polybutadienes (PBDs) were functionalized by diisocyanates, mostly by toluene diisocyanate (TDI), 23. Polymerizations were performed first in solvents for polydienes, such as hexane or decalin [54], and later in the monomer phase [55], but neither the yields nor the mechanical properties of the products proved satisfactory. 

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