Polycetyl methacrylate

TABLE 3.4. Conformational and Hydrodynamic Characteristics of Homopolymers of PM-16 and Polycetyl Methacrylate and Their Copolymers in Tetrachloromethane... 

The optical anisotropy of the segment of polymer 6 in Table 3.5 (polymers of p-methacrylylhydroxybenzoic acid cetyl ester, PCEM [55]) is ttj - 0x2 = -445 40 cm and the optical anisotropy of the monomeric unit is Aa = -18 10 cm. This value of Aa of PCEM is significantly higher than the optical anisotropy of molecules of polycetyl methacrylate (polymer 5 in Table... 

The orientation of the segments of a macromolecule in an electric field is cooperative in nature, where the orientation of each chain element causes the orientation of neighboring elements. This means that increases in the cooperative effect can be expected with an increase in the molecular weight. This hypothesis is confirmed by the dependence of the Kerr constant on the composition of the copolymer (cf. Fig. 3.9) and the different character of the dependence of K on M in the two compositions of the copolymer (cf. Fig. 3.13). The absolute values of K decrease with a decrease in the proportion of the nematogenic component (polymer PM-16 in the copolymer with polycetyl methacrylate), i.e., with a decrease in the intramolecular interaction (copolymer of 1 1 composition), and they are not dependent on the molecular weight (line 2 in Fig. 3.13) [81], which indicates attenuation of the cooperative character of the orientation of the individual kinetic units in an electric field. Such a decrease in the orientational order reflects a decrease in the absolute values of K (curve 2 in Fig. 3.12) with an increase in the temperature [79]. 

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See also in sourсe #XX -- [ , , ]

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