Effects on Structure and Properties of Polymers

10 BLOCK AND GRAFT COPOLYMERIZATION 11.10.1 Effects on Structure and Properties of Polymers 

The number and order of sequences may be more complicated. Block copolymers are usually made by free radical or living polymerizations. These processes can produce polymers that consist of a pure A block connected to a pure B block, with no interphase zone of mixed A and B structure. The preparation of block copolymers is not limited to monomers A and B, but can also encompass segments of random copolymers. For example, a block of a random copolymer AB can be connected to a block of polymer A or B. Moreover, the point of attachment of the blocks can be either at the end or the middle of the polymer chain. Several examples of the various types of block copolymers possibly follow  

When the sequences making up the segments are random copolymers, the prefix CO may be introduced, with the major component monomer preceding the minor constituent. A backbone polymer of butadiene-styrene rubber grafted with styrene containing a small percentage of acrylic acid would be described as poly[(butadiene-co-styrene)-(styrene-co-acrylic acid)] and could be schematically represented as 

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