Copolymer, graft random

Draw representative structures for (a) homopolymers, (b) alternation copolymers, (c) random copolymers, (d) AB block copolymers, and (e) graft copolymers of styrene and acrylonitrile. 

Other copolymers that may show micellization similarto that of BAB triblock copolymers include random copolymers if the hydrophobic units are located near both ends of the polymeric structure (Schild and Tirrell, 1991 Ringsdorf et al., 1992 Chung et al., 1999 Jones and Leroux, 1999), and graft copolymers if the hydrophobic blocks are grafted near both ends of a hydrophilic backbone. 

A comparison of the slloxane graft copolymers with random copolymers makes the former more attractive not only because of the possibility of synthesizing such tailor-made graft copolymers by the use of easily accessible slloxane macromers, but also because of the durability of surface modification characteristics Imparted by them. 

The present chapter is primarily concerned with the simultaneous polymerization of two monomers to produce random, statistical, and alternating copolymers. Graft copolymers and block copolymers are not synthesized by the simultaneous polymerization of two monomers. These are generally... 

Random Copolymers Alternating Copolymers Graft Polymers Block Copolymers... 

Acrylonitrile-butadiene-styrene copolymers (ABS) are random styrene-acrylonitrile copolymers grafted to butadiene, which are amorphous, opaque, and process easily. The properties depend on the ratios of the comonomers used. ABS is used in cosmetics packaging, and has been used in margarine tubs. 

As the components are incompatible they form some kind of dispersion. Mutual distribution of the polymers in the membrane depends very much on the method of preparation and may vary from random, when the membrane is made of e.g. copolymer grafted in solution, up to gradient when the ionic component penetrates the film of the inert polymer by means of diffusion and is then polymerized. 

Fig. 12.8 Schematic representations of various types of copolymers (a) random, (b) alternating, (c) diblock, (d) triblock, (e) single-graft, (f) multigraft and (g) cross-linked graft.

Figure 13.2. Polymer blend classification scheme. Random copolymers, block copolymers, graft copolymers, IPN s, a mechanical blends of various...

Figure 23-3. Arrangement of cooperatively operating catalytic positions in (A) graft copolymers (B) random copolymers and (C) conformationally prearranged (before introduction into polymer) groups.

The polymer-based miscible systems can be either intermolecular mixtures, for instance polymer solutions and blends, or intramolecular mixtures, such as block copolymers, star-shape multi-arm copolymers, grafted copolymers, random copolymers, and gradient copolymers with a composition gradient from one chain end to the other. Polymer-based miscible systems can phase separate into segregated phases with stable interfaces, or crystallize into crystalline ordered phases. In other words, there are two types of phase transitions, phase separation and crystallization. Under proper thermodynamic conditions, two phase transitions may occur simultaneously. The interplay of these two transitions will dictate the final morphology of the system. In the following, we will choose polymer solutions as typical examples to introduce the polymer-based miscible systems. 

Alternating copolymer Random copolymer Block copolymer Graft copolymer... 

Theoretical models for other systems, such as star, branched, and ring polymers, random and alternating copolymers, graft and block copolymers are discussed in the book by Mattice and Suter [1]. Block copolymers are discussed in Chap. 32 of this Handbook [2]. Theories of branched and ring polymers are presented in the book by Yamakawa [3]. Liquid-crystalline polymers are discussed in the book by Grosberg and Khokhlov [4], and liquid crystalline elastomers in the recent book of Warner and Terentjev [5]. Bimodal networks are discussed by Mark and Erman [6,7]. Molecular theories of filled polymer networks are presented by Kloczkowski, Sharaf and Mark [8] and recently by Sharaf and Mark [9]. 

Copolymer (i)k6- pa-l9-m9r (1936) n. This term usually, but not always, denotes a polymer two chemically distinct monomers. It is sometimes used for terpolymers, etc, containing more than two types of mer units. Three common types of copolymers are block copolymers, graft copolymers, and random copolymer. The lUPAC term for a polymer derived from two species of monomer, bipolymer eschews the foregoing ambiguity but is nevertheless rarely seen or heard. 

Fig. 1. Graft Copolymers (1) random graft copolymer (identical branches randomly distributed along the backbone) (2) regular graft copolymer (identical branches equally spaced along the backbone) (3) simple graft copolymer (3-miktoarm star copolymer) and (4) graft copolymer with two trifunctional branch points. Exact graft copolymers.

Scheme Pll.5.1 Graft copolymer synthesis random copolymer of styrene and ethyl acrylate grafted onto polystyrene (Problem 11.5). (Drawn following the synthesis method of Hawker, 1995.)...

Co-assembly of neutral-ionic blocks, 2009 [42] graft, random copolymers with oppositely chaiged species in aqueous solution synthetic (co)polymers of various architectures biopolymers multivalent ions metallic nanoparticles surfactants polyelectrolyte block copolymer micelles metaUo-supramolecular polymers... 

These are prepared by grafting random copolymers of styrene and 2- or 3-vinylthiophene with thiophene [92,94]. 

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