Copolymer , graft multicomponent

The most complete theoretical treatment of MaxwellAVagner polarization process in polymer blends was done by Steeman and coworkers (Steeman and van Tumhout 2003) especially also for higher concentrations of the dispersed phase and multicomponent polymer blends (Steeman et al. 1994 Steeman and Maurer 1990, 1992). Quantitative conclusions about the phase structure of the different systems can be drawn including the modeling also of interfaces. This has also some impact on blend compatibilization by grafted copolymers (Eklind et al. 1997). 

The behavior of multicomponent polymer systems has been the subject of several recent reviews. Bucknall has examined polymer blends and grafts, with particular reference to the toughening of plastics. All aspects of block copolymers have been explored by Noshay and McGrath. Manson and Sperling reviewed the entire field of polymer blends and composites. 

Multiphase or multicomponent polymers can clearly be more complex structurally than single phase materials, for there is the distribution of the various phases to describe as well as their internal structure. Most polymer blends, block and graft copolymers and interpenetrating networks are multiphase systems. A major commercial set of multiphase polymer systems are the toughened, high impact or impact modified polymers. These are combinations of polymers with dispersed elastomer (rubber) particles in a continuous matrix. Most commonly the matrix is a glassy amorphous thermoplastic, but it can also be crystalline or a thermoset. The impact modified materials may be blends, block or graft copolymers or even all of these at once. 

The methods of separation and identification of multicomponent polymers are far different from the methods described previously for the statistical type of polymer. First, only the blends are separable by extraction techniques. The remainder are bound together by either chemical bonds or interpenetration. The interpenetrating polymer networks and the conterminously grafted polymers are insoluble in all simple solvents and do not flow on heating. The graft and block copolymers, on the other hand, do dissolve and flow on heating above T/and/or Tg. 

A special case of specific adhesion is when there are primary chemical bonds present. For example, graft or block copolymers may bond the different phases of a multicomponent material together see Chapter 13. Direct bonding to substrates is also encouraged in many systems. For example, maleic anhydride comonomers are used to bond to metallic surfaces. 

Multicomponent polymeric materials consist of polymer blends, composites, or combinations of both. A polymer blend has two definitions The broad definition includes any finely divided combination of two or more polymers. The narrow definition specifies that there be no chemical bonding between the various polymers making up the blend. Table 2.5 and Section 2.7 summarize the basic types of polymer blends based on the broad definition primarily these are the block, graft, star, starblock, and AB-cross-linked copolymers (conterminously grafted copolymers), interpenetrating polymer networks, as well as the narrow definition of polymer blends. More complex arrangements of polymer chains in space can be shown to be combinations of these several topologies. 

Deng X-X, Cui Y, Wang Y-Z, Du F-S, Li Z-C (2014) Graft copolymers with polyamide backbones via combination of Passerini multicomponent polymerization and controlled chain-growth polymerization. Aust J Chem 67(4) 555-561... 

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