Toluene , glass former

Figure 14. Imaginary part of the dielectric permittivity e,(co) of (a) fluoroaniline (7 — 173 K) and (b) toluene (Tg = 117 K), both type B glass formers showing in addition to the main relaxation (a-process) a secondary relaxation peak (p-process) numbers indicate temperature in K. Unfilled symbols represent data obtained from a broad-band spectrometer [6,153]. Filled symbols represent data from a high-precision bridge [137] interpolations for fluoroaniline (solid lines) were done by applying the GGE distribution (a-process) and a Gaussian distribution (p-process) of relaxation times [142], and these for toluene (dashed lines) were done by the gamma distribution (a-process) and a Gaussian distribution (p-process) [6] (cf. Section IV.C.2).

Figure 15. Time constants of the a- and p-processes of several glass formers, as determined by dielectric spectroscopy (DS), light scattering (LS), photon correlation spectroscopy (PCS), NMR, Kerr effect (KE), neutron scattering (NS), and viscosity o-Terphenyl (OTP, type A) NMR (crosses, [177-179]), DS (filled squares [151]), KE (unfilled circles [66]), viscosity (solid line [164]). m-Tricresyl phosphate (m-TCP, type A) NMR (crosses [15]), LS (unfilled squares [181]), DS (circles [180]) and viscosity (line [182]). m-Fluoroaniline (FAN, type B) DS (stars [153]). 2-Picoline (PIC, type A) LS (unfilled circles [183]), NS (filled triangles [184]), PCS (unfilled squares [65], DS (filled diamonds, [181]). Toluene (type B) NMR (+ [11]), DS (filled squares [153]) and LS (filled circles [185]).

Non-aqueous binary glass formers were studied by Micko et They worked on mixtures of toluene with polychlorinated biphenyl or picoline (with different isotopic compositions) at low temperatures and measured, among other properties, the H spin-lattice relaxation rates. The analysis of the data allowed conclusions on glassy dynamics. Bauer et reported a related study on mixtures of alcohol isomers, 4-methyl-3-heptanol and 2-ethyl-l-hexanol, making use of H and H relaxation experiments. 

Some properties of p-iPP differ significantly from those of a-iPP. In comparison with a-iPP, fi-iPP possesses lower crystal density, melting temperature and fusion enthalpy, but a similar glass transition temperature (Table 3). The chemical resistance of p-iPP seems to be lower than that of a-iPP. The former could be selectively extracted with hot toluene from samples of mixed polymorphic composition [8]. 

A second approach adopted by O Brien and co-workers (1841, 1849) is the preparation of bis(dithiocarbamate) complexes generated from trimethylethy-lene and trimethylpropylene diamines. The former gives fairly insoluble products that were not pursued, but the latter are soluble in toluene and benzene and were successftdly used to deposit thin films of ZnS and CdS on glass, which gave better quality films than [Cd(S2CNEt2)2]. 

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