Motoshi Matsuura

Aramid/poly(ether sulphone) blend : crystallization accelerated by the presence of amorphous polymer

Abstract An aramid, prepared by the polycondensation of bis(4-aminophenyl) ether with isophthaloyl chloride, was found to render a single-phase mixture with poly(ether sulphone) (PES) by solution casting. Crystallization of the blend was studied by wide-angle X-ray diffraction, Hv light scattering, differential scanning calorimetry, Fourier-transform infra-red spectroscopy and scanning electron microscopy. The crystallization of aramid was found to be accelerated dramatically by adding PES, e.g. the crystallization rate constant of a 50 50 blend was shown to be one decade higher than that of neat aramid at around 310°C. The accelerated crystallization was ascribed to the elevation of chain mobility of aramid by blending with PES. It may be caused by the decrease of Tg via blending of a low-Tg component (PES), but this contribution was estimated to be small. The major contribution seems to be due to the partial dissociation of aramid-aramid interactions and the ‘up-hill diffusion’ associated with the liquid-liquid phase separation.

Crystallization from Single-Phase Mixtures of Nylon 6 and Aromatic Polyamide.

代表的な結晶性高分子である脂肪族ポリアミド (ナイロン6) と芳香族ポリアミド (MXD6) との混合系は結晶性高分子同士で相溶性を有する数少ない組合せであることがわかった. 本混合系の融点近傍およびガラス転移点近傍における結晶化挙動を, 光学顕微鏡観察, 光散乱法ならびにX線回折により調べた結果, 融点近傍の高温域ではナイロン6, MXD6はそれぞれ独立に結晶化し (MXD6の結晶化が先行) 共晶を形成しないこと, またガラス転移点近傍の比較的低温ではナイロン6とMXD6の結晶化速度は大きく異なるにもかかわらず, 両ポリマーが同時に結晶化することがわかった.