Direct synthesis of a polyamide by an enol phosphite and imidazole

Direct polycondensation of various dicarboxylic acids and diamines was effected under mild conditions by using an enol phosphite, diethyl 1-methyl-3-oxo-1-butenyl phosphite (I), in the presence of imidazole. To check the activity of the enol phosphite and various organic bases in an amidation reaction, the model reaction of acetic acid and aniline was carried out, and the yield of acetanilide was estimated by means of gas chromatography. Among organic bases, imidazole was the best in terms of yield of acetanilide. Polycondensation performed by varying solvents, temperature, and amount of imidazole resulted in high yields of polyamides with inherent viscosities of 0.1-0.25.     

The packing structure of side chains of liquid-crystalline side-chain polymers before and during heat treatment

Six varieties of liquid-crystalline side-chain polymers, poly (cholesteryl ω-(methacryloyloxy)alkanoates) (p-ChMO-n, n = 1,2,3,4,5,7, the carbon number of the alkyl chain), were studied by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). On and after the first cooling run from the isotropic state, these polymethacrylates gave the same smectic phase. However, on the first heating run for virgin samples, unique phenomena were observed, similar to those frequently observed on the first heating run for thermotropic liquidcrystalline polymers. The thermal properties of the first heating run for these six polymers showed different tendencies between pChMO-n (n-1-3) and pChMO-n (4-7). Although the DSC curve of pChMO-n (n = 4, 5 and 7) exhibited the melting and clearing points on the first heating run, the DSC curve of pChMO-n (n = 1,2 and 3) exhibited an exothermal peak between the glass transition and the clearing point on the first heating run. This difference, probably due to the difference in the spacer length of these polymers, was investigated quantitatively by small-angle X-ray scattering by which the micro-change of the packing structure of the side chains of the polymers was traced.     

Polymerisation von makro cyclischen Formalen

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