Morphology-interface-toughness relationship in polyamide/polysulfone blends by reactive processing
Morphology-interface-toughness relationship in polyamide/polysulfone blends by reactive processing
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DOI：
10.1016/s0032-3861(99)00011-7
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发表时间：
1999-12
期刊：
影响因子：
4.6
通讯作者：
P. Charoensirisomboon-;Tsuneo Chiba;K. Torikai;H. Saito;T. Ougizawa;Takashi Inoue;Martin Weber
中科院分区：
文献类型：
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作者：
P. Charoensirisomboon-;Tsuneo Chiba;K. Torikai;H. Saito;T. Ougizawa;Takashi Inoue;Martin Weber
利用克级混合器（Mini-Max Molder）将聚酰胺6 （PA）与聚砜（PSU）反应共混，制备了一系列PA/PSU （80/20wt）。与不同直径的PSU颗粒共混；端邻苯二酸酐PSU （PSU- phah）为70nm，端环氧树脂PSU为0.4μm，马来酸酐接枝PSU为0.45μm，无反应PSU为1.3μm。通过光散射（LS）、小角x射线散射（SAXS）、广角x射线衍射（WAXD）和差示扫描量热法，表明共混物中PA基体的结晶形态没有差异。不同共混物的抗拉强度差异不大，但伸长率差异较大；PSU颗粒越小，断裂伸长率越大。PSU颗粒越小，共混物的体断裂韧性越高。特别是psu - phh共混物表现出非常高的韧性。通过扫描电镜观察，该共混物出现韧性断裂。透射电镜（TEM）观察证实了两相材料的均匀塑性变形，无界面脱粘。相反，其他共混物表现为脆性断裂并伴有界面脱粘。采用非对称双悬臂梁法测得的PA与PSU-PhAH相间的粘接强度明显高于其他体系。因此，当界面粘接强度高到足以提供足够的应力传递时，脆性PSU颗粒会发生塑性变形，从而使整个材料的均匀塑性变形具有较高的韧性。较低的界面附着力似乎屈服于较小的大规模塑性变形，从而导致较低的韧性。
By reactive blending of polyamide 6 (PA) with polysulfone (PSU) using a gram-scale mixer (Mini–Max Molder), we prepared a series of PA/PSU (80/20wt. ratio) blends with various diameters of PSU particles; 70nm by using phthalic anhydride-terminated PSU (PSU-PhAH), 0.4μm by epoxy-terminated PSU, 0.45μm by maleic anhydride-grafted PSU and 1.3μm by non-reactive PSU. By light scattering (LS), small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry, it was shown that there did not exist any difference in the crystalline morphology of PA matrix among the blends. Although difference in tensile strength among blends was small but on elongation it was large; the smaller PSU particles yielded larger elongation at break. The bulk-fracture toughness was shown to be higher for the blend with smaller PSU particles. Especially, PSU-PhAH blend showed a remarkably high toughness. In this blend, ductile fracture was shown by SEM observation. Transmission electron microscopic (TEM) observation confirmed the homogenous plastic deformation without interfacial debonding in the two-phase material. In contrast, other blends showed brittle fracture accompanied with interfacial debonding. The adhesive strength between PA and PSU-PhAH phases measured by asymmetric double cantilever beam method was shown to be much higher than in other systems. Thus, when the interfacial adhesive strength is high enough to provide adequate stress transfer, plastic deformation of brittle PSU particle can occur and hence the uniform plastic deformation of the whole material may render high toughness. The lower interfacial adhesion seems to yield in less massive plastic deformation to resulting in lower toughness.