4-Polydienes, chemical modifications

Chemical modification of polydienes - The studies of CAMERON et al.lOb-Dyf may considered quite representative of recent trends in this very rich field( 0). Addition in solution of aryl or alkylsulfenyl chlorides accross the double bond is selective and may be quantitative furthermore it is regioselec-tive and yields block copolymers for partial modification (R=H or CH3) ... 

The reactivity of conjugated double bonds is significantly different from that of isolated double bonds in the polymer backbone of polydienes. This difference can be used for selective chemical modification of the dienes with reactions such as the Diels—Alder reaction. With maleic anhydride as an enophile, selective addition to the terminal pair of conjugated double bonds in a chloroprene oligomer is complete in a few hours to give 102.391... 

Solution reactions of polydienes illustrate the diversity of chemical modifications on polymers (Scheme 11). Such polymers can be isomerized, cyclized, hydrogenat, epoxidized, and reacted with carbenes or enophiles. Most of these transformations increase the Tg s of the polymers with a consequent change in the physical/mechanical properties of the materials. 

Sjmip. 73-98 (1975), Recent Developments in Chemical Modification of Polydienes . 

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