Copolymer , graft diagram

By also using the LASIP procedure, grafted PS-b-PI and PBd-b-PS block copolymers have been prepared (Fig. 7) [72]. Using silane and thiol-DPE initiators, polymerization was carried out on the SiOx and Au surface by sequential addition of monomers. Typically, after allowing this first reaction to reach completion, the second monomer was added to the living anion, and polymerization of the second block was allowed to proceed. The polymerization was also investigated by SPS [80], AFM, ellipsometry, FT-IR, and XPS. The schematic diagram for the reaction on Au surfaces and the formation of the block copolymers is shown in Fig. 6. The results are summarized in Table 2. 

Fig. 2.35).The synthesis and morphology of more complex trifunctional branched graft copolymers have recently been discussed. Gido et al. (1996) prepared PS2-PI-PS2 (H-shaped) and (PS-PI)PI(PS-PI) ( -shaped) copolymers (see Fig. 2.33). The observed morphology of these samples was compared to the theory of Milner, the comparison being facilitated by considering the H- and -shaped molecules to each be composed of two single graft copolymers. This generally produced a satisfactory mapping onto the phase diagram in Fig. 2.34.

The formation of the graft copolymers was proved by the analysis of the fractions I-IV obtained through extraction and l SO and NaOH treatment, according to the schematic diagram presented in Figure 2. The IR spectra of the insoluble fractions II and soluble fraction III present absorption bands (19,20) characteristic of those of the control rayon and of the polymers P-1 -P-4, as it can be seen in Table III and Figure 3, respectively. 

The most common polymeric silicone surfactants are based on polyoxyalkylene groups. The structures of graft-type (rake-type) and ABA structures are illustrated in Figures 6.17 and 6.18. It should be noted that there are many possible variants of these basic structures. The actual structure of graft-type silicone copolymers is a random copolymer of m and n rather than the blocky structure suggested by the diagram. 

FIGURE 6-3 Schematic diagram illustrating the formation of a graft copolymer. ... 

FIG. 6 Emulsion type diagram of ra-dodecane-water emulsions ( = 0.5) stabilized with hydrophobically modified poly(sodium acrylate)s effect of changing the degree of grafting and type of the graft (single versus twin-tailed). Salt is used as a tool to estimate the copolymer HL properties. (From Ref. 152.)... 

In contrast to the situation found for dilute solutions, the behavior of nonlinear block copolymers in the solid state seems to have attracted great attention. Many theoretical publications appeared in recent years, dealing mainly with the phase behavior of star-block, simple graft and comb copolymers. Issues like the nature of the phase diagram and the order-disorder transition have been studied in considerable detail. The compatibilizing effects of complex copolymers, in comparison to simple diblock copolymers, were also investigated. 

Block and graft copolymers possessing segments with chemical structures which are the same as those of the polymers to be blended are effective com-patibilizing agents. Thus, an AB block or graft copolymer compatibilizes polymers A and B (see Diagram 1). 

Modification of Mechanical Properties. Application of these concepts is illustrated by impact polystyrene polystyrene (PS) grafted onto polybutadiene (PBD) permits as much as 40% PBD in PS to be incorporated whereas, in the absence of the graft copolymer, incompatibility is detectable by stratification when more than 10% elastomer is blended with PS (Diagram 3). Acrylonitrile-... 

ABS-type resins are used as impact modifiers for PVC, but the resultant blend has insufficient transparency for application in clear bottles. Transparency can be obtained by grafting PMMA onto crosslinked PBD (5) or poly (butyl acrylate) (6) which has been previously grafted onto PS (Diagram 4). In this case the PMMA branch is compatible with PVC by virtue of its solubility parameter, and optical clarity results from suitable component ratios in the graft copolymer so that the refractive index matches that of PVC. The desired results are not obtained if a copolymer of methyl methacrylate and styrene is... 

An impact resistant PVC-acrylic polymer alloy is formed by grafting PMMA onto poly (ethylhexyl acrylate) (PEHA) and then blending the resultant mixture of graft copolymer and homopolymers with PVC (7) (Diagram 5). 

The compatibility of PMMA and PVC is also used in adhesives for applying PVC decorative film to wooden or gypsum surfaces a mixture of PMMA and an epoxy resin makes a useful adhesive. The less than 10% compatibility of PMMA with the epoxy resin limits the level of adhesion. However, by polymerization of methyl methacrylate in the presence of epoxy resin, up to 30% PMMA in the composition is compatibilized because of in situ generation of the graft copolymer (Diagram 11). 

Figure 27.5 Schematic diagram showing interactions of block and graft copolymers through the interface.

Figure 3.9 Diagram of a graft copolymer capital letters represent different monomers...

FIGURE 1.1 Schematic diagram of (a) statistical, (b) alternating, (c) block, and (d) graft copolymers. 

Figure 7. Retention diagrams of >L-dodecane on graft copolymers with PSMA branches (M =4460). SMA contents in.wt % (1) 100 (PSMA homopolymer) (2) 69 (3) 50 (4) 30 (5)...

Rgure 1 Schematic diagram of common copolymer architectures (a) AB diblock copolymers (b) linear ABA triblocks (c) linear ABC triblocks (d) linear ABAB. .. multiblocks, which can terminate with either an A or a B block (e) graft copolymers, illustrated with B side chains grafted to an A backbone (f) multiann star copolymers, illustrated as a four-arm star with the B blocks joined at the center. 

Schematic diagram illustrating the process of immobilization of trichlorosilane coupling agent on the ITO surface, surface-initiated ATRP of GMA from the ITO-Cl surface to produce the inner block, followed by block copolymer of FMMA and the coupling of GOD to the epoxide groups of the P(GMA) (scheme 1). In scheme 2, P(FMMA) is first grafted from the ITO-Gl surface, and the P(GM A) segment is then grafted as the outer block of the copolymer. (Reproduced from Zhang et al. 2010. Enzyme-mediated amperometric biosensors prepared via successive surface-initiated atom-transfer radical polymerization. Biosensors Bioelectronics 25 (5) 1102-1108, with permission from Elsevier.)...

There is an extensive literature describing solution polymerization processes. " In this chapter, emphasis is on only those aspects directly related to the synthesis of rubber-modified plastics, which requires discussion of the ramifications resulting from the two-phase nature of the polymerizing systems. Of key interest are the phase diagram and its interpretation, formation of the graft copolymer and crosslinking. These will now be addressed. 

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