The molecular‐weight dependence of the glass‐transition temperature (Tg) of a series of atactic polyacrylonitriles (PAN)s was studied by inverse gas chromatographic (IGC) analysis. PANs having different molecular weights were prepared by either; (i) the addition of isopropyl alcohol as a chain‐transfer agent, or (ii) a scission reaction induced by the addition of alkali (NaOH) to a solution (N,N‐dimethylformamide solution, at 25 °C) of the resulting polymer. The intrinsic viscosity [η] was in the range of 10.9–0.1 (dl · g−1), which corresponds to a viscosity‐averaged molecular weight (Mv) of 1 590 000–3 000. As part of the results, a side reaction, which saw the conversion of the nitrile (CN) groups of PAN into amide (CONH2) and/or carboxylic acids (COOH) groups by alkali, was found to occur. The typical molecular‐weight dependence of the Tg in free‐radically prepared PAN was discussed in connection with a chain‐transfer mechanism in an aqueous medium.Molecular‐weight dependence of the Tg for PAN (WA). An error bar is given by a short vertical arrow.magnified imageMolecular‐weight dependence of the Tg for PAN (WA). An error bar is given by a short vertical arrow.

The glass‐transition temperature (Tg) of several atactic monodisperse polystyrenes (PSt)s was studied by an inverse gas chromatographic (IGC) analysis, as a preliminary study for the detection of the Tg of polyacrylonitrile. The Tg of PSt with different molecular weights was clearly obtained by this method. The agreement in the Tg values obtained by IGC and by differential scanning calorimetry (DSC) was quite good within the molecular‐weight range Mp = 7 600–2 430 000 (where, Mp = (Mn × Mw)1/2). This method has a wide universality for the detection of the Tg of polymers. Several essential factors were extracted for the establishment of the optimum conditions for IGC measurements, such as the concentration of polymer toward a clay matrix (10 wt.‐%), and the type of lower probe, decane. The best probe was determined empirically from the most effective detection in the IGC measurements of PSt.Molecular‐weight dependence of the Tg of PSt. Experimental data obtained here are indicated by an arrow. Other data was taken from ref.21magnified imageMolecular‐weight dependence of the Tg of PSt. Experimental data obtained here are indicated by an arrow. Other data was taken from ref.21

Behavior of dry corrosion which is electrochemical reaction between Al Mg Si alloy 6063 and ethanol in gasoline has been investigated. Dry corrosion has not been observed in E3 (3 ethanol) and E10 (10 ethanol) at room temperature, but observed in E3 and E10 when a small amount of aluminum chloride had been added to them at room temperature. The higher solution temperature is, the more often the dry corrosion occurs. Dry corrosion has also been observed in the above solution environments in which 0.1 and 1 water contained. Occurrence of dry corrosion was detected by the area polarization method, which revealed that initiation and propagation of the dry corrosion corresponds to the decrease of anodic polarized resistance of 6063.

Aluminum ethyleneglycoxides, Al OCH 2 CH 2 OH 3 were obtained when aluminum powder mixed with AlCl 3 has been refluxed in dehydrated ethylene glycol at 471 K for 12 h. Characteristics of the aluminum ethyleneglycoxide were measured by XRD and particle size distribution analysis. Particle morphology observed by SEM was like rectangular column shape. It is considered that the aluminum ethyleneglycoxides obtained is interpreted as corrosion product which is a reaction product that aluminum was corroded in ethyleneglycol.