Graft copolymers general

Poly (ary lene ether sulfone)s and poly(arylene ether ketone) have been employed to prepare block and graft copolymers. Generally, the block copolymers can be prepared by reacting functional-group-terminated oligomers with other functional oligomers and monomers. 

Hybrid Graft Copolymers. The most widespread complex hybrid structures are the graft copolymers. Generally, all typical grafting techniques have been applied for the preparation of synthetic polymer/PLL hybrid graft copolymers. 

Acrylamide graft copolymers such as those with starch (qv)(131), dextran (132), and lignin (qv) (133), have been studied to try to reduce copolymer costs. A general disadvantage of acrylamide copolymers is greater cost compared to partially hydroly2ed polyacrylamides. 

Two commercially significant graft copolymers are acrylonitrile—butadiene—styrene (ABS) resins and impact polystyrene (IPS) plastics. Both of these families of materials were once simple mechanical polymer blends, but today such compositions are generally graft copolymers or blends of graft copolymers and homopolymers. 

Another factor that affects the extent of grafting is the nature and the concentration of the monomer. Generally, maximum graft copolymer is observed at an opti-... 

These two parameters give the quantitative measurement of the grafting reaction. The general characterization of the graft copolymer is based on the following ... 

Generally, a graft copolymer should offer a clear advantage over the physical blend when a high degree of incompatibility exists between the component parts. It is... 

Generally, the number of the shell chains in a microsphere ranges from a few hundred to a few thousand. The range of the diameter of the core is from 10-100 nm. Such a core-shell structure is very similar to the (AB)n type star block copolymers, which have many arms and spherical polymer micelles of the block or graft copolymers formed in selective solvents that are good for the corona sequence and bad for the core sequence. In fact, many theoretical investigations of the chain con-... 

In terms of structural control, block copolymers have considerable advantages over graft copolymers. The segment length and sequence are generally more easily controlled for block copolymers than for graft copolymers. 

M, in their reaction mixtures. In general, as the mass fraction of hydrolyzable sidechain in the graft copolymer increases, the... 

A graft copolymer consists of a linear Polymer chain of one type to which has been grafted side-chains of a different type of polymer. The formation of a graft copolymer can be brought about by either of two general methods ... 

Generally the graft copolymers are made up of a main homopolymers chain with branches of another... 

The reaction scheme is very general, but control over the extent of the intermolecular reactions and the distribution of the number of arms in the star is limited. The arm first method includes the polymerization (to form star polymers) or copolymerization (to form comb or graft copolymers) of macromonomers. The technique provides a handy simplification if the arm MW need not be very high and the MW control of the branched polymers is not very important. 

In principle the composition of a copolymer may also be determined by analyzing the composition of the residual monomer by a suitable method after polymerization. It will usually be necessary first to separate the copolymer by precipitation, followed by careful recovery of the filtrate containing the residual monomer, but the direct method of analysis of the copolymer will generally be preferred. Block and graft copolymers can be characterized in the same manner. However, consideration must be taken of the fact that they usually contain large... 

Graft copolymers should in principle exhibit similar structure/properties relationships as block copolymers. The problem is that pure graft copolymers which are not accompanied by large amounts of homopolymers are - with few exceptions - very difficult to synthesize. This is the reason why reliable property data in relation to the structure of graft copolymers only in few cases are available, but these can not be generalized. 

Block copolymers are linear, but graft copolymers are branched, with the main chain generally consisting of a homopolymer or a random copolymer, while the grafted side chains are composed of either the same or another monomer or several monomers ... 

In general, graft copolymers play often a role as compatibilizer in polymer blends (see Sect. 5.5). 

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