A strategy for toughening epoxy thermosets via topological rearrangement of cross-linked networks is presented. Amine-cured epoxy systems were modified by mixing partially reacted substructures (mPRS), which were synthesized by partially curing tetraglycidyl ether of diaminodiphenylmethane (TGDDM) and polyether monoamine (Jeffamine M1000) to provide free unbound surfaces that enhance protovoid formation during deformation. The influence of mPRS conversion and weight ratio on the properties of diglycidyl ether of bisphenol A (DGEBA) and TGDDM systems cured with Jeffamine D230 was investigated. Adding mPRS resulted in high T_g systems capable of exceptional strain at failure in tension: 43% for the DGEBA (T_g = 75 °C) and 20% for the TGDDM (T_g = 135 °C). The addition of mPRS, however, decreases T_g relative to unmodified systems. SEM and SAXS characterization provide evidence of protovoid (18–34 nm) formation. Quasi-static compressive tests conducted at testing temperatures selected to maintain a constant (T_g - T_test) reveal the protovoid opening mechanism plays a dominant role in enhanced ductility.

提出了通过交联网络的拓扑重排来增韧环氧热固性树脂的策略。通过混合部分反应的子结构（mPRS）对胺固化的环氧体系进行改性，该结构通过将二氨基二苯甲烷的四缩水甘油醚（TGDDM）和聚醚单胺（Jeffamine M1000）进行部分固化而合成，以提供自由的未结合表面，从而增强变形过程中原孔的形成。研究了mPRS转化率和重量比对双酚A二缩水甘油醚（DGEBA）和用Jeffamine D230固化的TGDDM体系的性能的影响。添加mPRS会导致高T _g系统，该系统能够在拉伸失败时产生出色的应变：DGEBA（T _g  = 75°C）为43％，TGDDM（T _g为20％） = 135°C）。然而，相对于未修饰的系统，mPRS的添加会降低T _g。SEM和SAXS表征提供了原生空（18–34 nm）形成的证据。在选择保持恒定的测试温度下进行的准静态压缩测试（T _g -T_测试）显示，原生空洞打开机制在增强延展性方面起着主要作用。