Conformation Copolymers

Experiments were also performed with the aim of polymerizing a mixture of two monomers (69). The reaction rate and the composition of the graft copolymer conform to the rules of mechanochemical synthesis and radical copolymerization. If the two monomers have almost equal reactivities, the composition of the copolymer is approximately that of the initial monomer mixture (Fig. 20). The... 

Table 1 Effect of A and B solubility on copolymer conformation during the coloring process...

Bracco, S., Comotti, A, Simonutti, R., Camurati, L, Sozzani, P., Low-temperature crystallization of ethylene-ran-propylene copolymers conformational rearrangement of sequences during the formation of the aggregates. Macro-molecules 2002, 35 1677-1684. 

Experiments were also performed with the aim of polymerizing a mixture of two monomers [88]. The reaction rate and the composition of the graft copolymer conform to the rules of mechanochemical synthesis and radical copolymerization. If the two monomers have almost equal reactivities, the composition of the copolymer is approximately that of the initial monomer mixture (Fig. 5.20). The reaction rate is also intermediate between those of the separate monomers. If the two mechanically activated monomers have different reactivities, the two monomers largely polymerize separately. The reaction rate depends on the polymer properties for the monomer that polymerizes first. As an example, in the system chloroprene-methyl methacrylate [88], the more active chloroprene polymerizes at first the reaction rate is low as polychloroprene is a flexible chain and the second monomer behaves as an inert solvent, reducing the viscosity. The reaction rate increases in the second part of the reaction when an appreciable amount of poly-(methyl methacrylate) is produced (see Fig. 5.21). Two monomers added... 

Fig. 10 Copolymer conformations top) and corresponding midblock fiactions from simulations bottom)...

An overview of the experimental findings of the systematic SANS investigations of different combinations of PEB-n copolymers and wax molecules was done in terms of structiue diagrams for each of the investigated polymer-wax mixed systems [12]. These diagrams display temperature versus wax volume fraction maps that indicate the different structures found by SANS experiments and reveal the wax and copolymer conformation within the joint formed structures (Figs. 33-35). 

We finish off this section by showing some pictures of typical copolymer conformations obtained from Monte Carlo simulations using a modification of the program developed by Clark et The chain does a self-avoiding walk on a diamond lattice, and interaction energies ab... 

No.5, 26th Feb. 2002, p. 1677-84 LOW-TEMPERATURE CRYSTALLIZATION OF ETHYLENE-RAN-PROPYLENE COPOLYMERS. CONFORMATIONAL REARRANGEMENT OF SEQUENCES DURING THE FORMATION OF THE AGGREGATES... 

Figure 10 Schematics of two-dimensional chain conformations of the block copolymer and the microsphere in a binary blend [36].

The efficiency of the copolymers, either block or graft, acting as the compatibilizer depends on the structure of the copolymers. One of the primary requirements to get maximum efficiency is that the copolymer should be located, preferentially at the blend interface (Figs. 2a, b, and c). There are three possible conformations, as shown in the figure. Many researchers [10-12] found that the actual conformation is neither fully extended nor flat (Fig. 2c). A portion of the copolymers penetrates into the corresponding homopolymer and the rest re-... 

Figure 2 Conformation of copolymer at the blend interface (a) completely extended, (b) completely flat, and (c) neither completely extended nor completely flat.

The copolymer with the structure shown in Figure 16-15 displays a behavior similar to that of Ooct-OPV5-CN. In solution, one finds a fast double-exponential decay, while in a polysulfonc matrix single-exponential decay with a time constant of l. 7 ns is observed. We attribute this behavior to the same conformational phenomena. 

The possibility of conformational changes in chains between chemical junctions for weakly crosslinked CP in ionization is confirmed also by the investigation of the kinetic mobility of elements of the reticular structure by polarized luminescence [32, 33]. Polarized luminescence is used for the study of relaxation properties of structural elements with covalently bonded luminescent labels [44,45]. For a microdisperse form of a macroreticular MA-EDMA (2.5 mol% EDMA) copolymer (Fig. 9 a, curves 1 and 2), as compared to linear PM A, the inner structure of chain parts is more stable and the conformational transition is more distinct. A similar kind of dependence is also observed for a weakly crosslinked AA-EDMA (2.5 mol%) copolymer (Fig. 9b, curves 4 and 5). 

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