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Structure of glassy polymers

The general principles of the structure of glassy polymers and their rubber-modified derivatives, and of the molecular and morphological parameters have been thoroughly investigated. [Pg.277]

We shall conclude with some remarks on the structure of glassy polymers. If one frequently speaks of glass structures, this does not mean that there exists one definite glass structure similar to a crystal. In a macromolecular solid-e.g., the polystyrene-plasticizer system, entirely different glasses are obtainable, the macroscopic composition of which is always the same (8). In Figure 10 the full... [Pg.66]

Thus, one could conclude that the molecular structure of glassy polymers has only a small effect on the relaxation processes associated with the nonequilibrium thermodynamic state of the glasses. [Pg.257]

Experimental means of characterization of the structure of glassy polymers... [Pg.54]

The reaction of curing the epoxy-amine system occurring in the diffusion-controlled mode has little or no effect on the topological structure of the polymer 74> and on its properties in the rubbery state. However, the diffusion control has an effect on the properties of glassy polymers 76 78). [Pg.136]

Petrie, S. E. B. The effect of excess thermodynamic properties versus structure formation on the physical properties of glassy polymers. J. Macromol. Sci., Phys. 12, 225 (1976)... [Pg.55]

The model system is a cube of glassy polymer with 3D periodic boundaries, filled with chain segments at a density corresponding to the experimental value for the considered polymer. The entire contents of the cube are formed from a single parent chain with the chemical structure of the polymer. The cube can thus be considered as part of an infinite medium, consisting of displaced images of the same chain, as shown on Fig. 58. [Pg.94]

In this section we will discuss the molecular structure of this polymer based on our results mainly from the solid-state 13C NMR, paying particular attention to the phase structure [24]. This polymer has somewhat different character when compared to the crystalline polymers such as polyethylene and poly(tetrameth-ylene) oxide discussed previously. Isotactic polypropylene has a helical molecular chain conformation as the most stable conformation and its amorphous component is in a glassy state at room temperature, while the most stable molecular chain conformation of the polymers examined in the previous sections is planar zig-zag form and their amorphous phase is in the rubbery state at room temperature. This difference will reflect on their phase structure. [Pg.84]

The results presented in Table II show that even small amounts of gas affect the cooperative main-chain molecular motions of glassy polymers. Evidence that the presence of gases in polymer cause structural and dynamic changes can be seen in the depression of the Tg (42, 43, 44), and in the increased viscoelatic relaxation rates (43, 44) of... [Pg.111]

A relatively high sb 12.30>35> in the glassy state is possible and it is not related to the inhomogeneous structure of the polymers. As it will be shown in Sect. 5.1.2., the largest possible elongation of intercrosslinked chains of these polymers is about 50 %. [Pg.76]

We have reviewed the recent development of a nonequilibrium statistical mechanical theory of polymeric glasses, and have provided a unified account of the structural relaxation, physical aging, and deformation kinetics of glassy polymers, compatible blends, and particulate composites. The specific conclusions are as follows ... [Pg.188]

For ionomer samples with low ion. content (less than 5 mol %), only crazes are formed. Figure 24 shows a typical TEM picture of a craze in a deformed thin film of an ionomer with low ion content. This can be compared with the craze structure of starting PS (Fig. 12b). Also, in Fig. 25 two views of the craze microstructure in PS (Fig. 25a and b) are compared with corresponding views (Fig. 25c and d) of the craze structure of the ionomer containing 4.8 mol % ion content. These micrographs show typical structural features of crazes of glassy polymers a) a midrib of lower fibril... [Pg.109]


See other pages where Structure of glassy polymers is mentioned: [Pg.301]    [Pg.304]    [Pg.2523]    [Pg.413]    [Pg.1]    [Pg.174]    [Pg.213]    [Pg.220]    [Pg.301]    [Pg.304]    [Pg.2523]    [Pg.413]    [Pg.1]    [Pg.174]    [Pg.213]    [Pg.220]    [Pg.2361]    [Pg.203]    [Pg.223]    [Pg.235]    [Pg.159]    [Pg.205]    [Pg.22]    [Pg.34]    [Pg.44]    [Pg.327]    [Pg.131]    [Pg.297]    [Pg.126]    [Pg.69]    [Pg.69]    [Pg.101]    [Pg.317]    [Pg.62]    [Pg.144]    [Pg.152]    [Pg.63]    [Pg.260]    [Pg.145]    [Pg.407]    [Pg.65]    [Pg.278]    [Pg.304]    [Pg.305]   
See also in sourсe #XX -- [ Pg.59 ]

See also in sourсe #XX -- [ Pg.304 ]




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