Polybutadiene synthesis procedure

Styrene and butadiene also form copolymers known as high impact polystyrene, or rubber-modified polystyrene, when the content of butadiene is 10%. This type of material has excellent mechanical properties, and it is widely used in practice for the manufacturing of numerous objects, including parts for household appliances, furniture, etc. Rubber-modified polystyrene is commonly used as wood replacement and also for packaging. The synthesis of this material typically is done by dissolving polybutadiene in styrene monomer, followed by free radical polymerization achieved using a peroxide catalyst. This procedure leads to block or graft type copolymers. 

These procedures have also been applied to the synthesis of 1,1-dipheny-lethylene-functionalized polybutadiene macromonomers (79) [208, 209]. The general reaction scheme is shown in Eq. (45) ... 

Isothermal crystallization of a model hydrogenated polybutadiene, HPB (M of 25Kg/mol, polydispersity index of 1.01, 10 wt% ethyl branches) was carried out on a Perkin-Elmer DSC7 (the synthesis and experimental procedure for the preparation of the HPB has been described in Refs [77,78]). 

The anionic arm-first methods can also be applied to the synthesis of star block copolymers [59]. The procedure is identical except that living diblock copolymers (arising from sequential copolymerization of two appropriate monomers, added in the order of increasing nucleophilicity) are used as living precursor chains. The active sites subsequently initiate the polymerization of a small amount of a bis-unsaturated monomer (DVB in most cases) to generate the cores. If polystyrene and polyisoprene (or polybutadiene) are selected, the resulting star block copol)miers behave as thermoplastic elastomers because of their different glass transition temperatures. 

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