Epoxy resins are inherently brittle due to their high crosslink density. Hybridization of epoxies with a thermoplastic phase is an effective solution for reducing the brittleness and improving the toughness without impairing the thermal and mechanical properties. The present study focuses on the development of a novel room temperature curable epoxy resin by blending with different proportions of hydroxyl terminated poly (etheretherketone)s (PEEKTOH) as thermoplastic toughening agent. The systems were cured using triethylenetetramine (TETA). Isothermal rheological studies showed that, incorporation of PEEKTOH phases reduced the gelation time of the blend from 175 min to 30 min. The glass transition temperature of the blends were improved marginally (from 74 to 80 °C) as evidenced by dynamic mechanical thermal analysis studies. The toughened and the unmodified systems were examined for their adhesive properties on aluminium substrates. It was noted that, about 19% improvement in lap shear strength (LSS) was achieved for the toughened adhesive. Higher proportions of PEEKTOH in the epoxy matrix led to increased viscosity which consequently reduced the wetting characteristics, as proven by contact angle measurements. The fracture toughness of the cured blends improved up to 86%. Fracture morphology evaluation by scanning electron microscopy (SEM) showed a brittle fracture for the unmodified epoxy and a phase separated morphology for the toughened blends. Transparency was reduced in the toughened formulations due to phase separation of PEEKTOH.

环氧树脂由于其高的交联密度而固有地易碎。环氧树脂与热塑性相的杂化是在不损害热和机械性能的情况下降低脆性和提高韧性的有效解决方案。本研究致力于通过与不同比例的羟基封端的聚（醚醚酮）（PEEKTOH）混合作为热塑性增韧剂，开发一种新型的室温可固化环氧树脂。使用三亚乙基四胺（TETA）固化系统。等温流变学研究表明，掺入PEEKTOH相可将共混物的凝胶化时间从175分钟减少至30分钟。动态机械热分析研究表明，共混物的玻璃化转变温度略有提高（从74到80°C）。检查了增韧和未改性体系在铝基材上的粘合性能。注意到，对于增韧的粘合剂，搭接剪切强度（LSS）提高了约19％。接触角测量证明，较高的PEEKTOH在环氧基体中的比例会导致粘度增加，从而降低润湿性。固化共混物的断裂韧性提高了86％。通过扫描电子显微镜（SEM）进行的断裂形态评价表明，未改性的环氧树脂具有脆性断裂，而增韧的共混物具有相分离的形态。由于PEEKTOH的相分离，增韧配方的透明度降低。增韧粘合剂的搭接剪切强度（LSS）提高了约19％。接触角测量证明，较高的PEEKTOH在环氧基体中的比例会导致粘度增加，从而降低润湿性。固化共混物的断裂韧性提高了86％。通过扫描电子显微镜（SEM）进行的断裂形态评价表明，未改性的环氧树脂的脆性断裂和增韧的共混物的相分离形态。由于PEEKTOH的相分离，增韧配方的透明度降低。增韧粘合剂的搭接剪切强度（LSS）提高了约19％。接触角测量证明，较高的PEEKTOH在环氧基体中的比例会导致粘度增加，从而降低润湿性。固化共混物的断裂韧性提高了86％。通过扫描电子显微镜（SEM）进行的断裂形态评价表明，未改性的环氧树脂的脆性断裂和增韧的共混物的相分离形态。由于PEEKTOH的相分离，增韧配方的透明度降低。固化共混物的断裂韧性提高了86％。通过扫描电子显微镜（SEM）进行的断裂形态评价表明，未改性的环氧树脂的脆性断裂和增韧的共混物的相分离形态。由于PEEKTOH的相分离，增韧配方的透明度降低。固化共混物的断裂韧性提高了86％。通过扫描电子显微镜（SEM）进行的断裂形态评价表明，未改性的环氧树脂的脆性断裂和增韧的共混物的相分离形态。由于PEEKTOH的相分离，增韧配方的透明度降低。