Castor oil (CO) derived polyurethane networks exhibit poor mechanical properties and non-reprocessibility due to flexible, highly and permanently cross-linked network structures. To overcome these defects, we designed and fabricated a series of poly (urethane urea) (PUU) networks by reacting CO-based polyurethane precursor with different amounts of 4-aminophenyl disulfide (APD). The equilibrium swelling behavior, mechanical properties, stress relaxation and reprocessibility of the COPUU networks were investigated in detail in this study. The swelling ratio increased with increasing APD content due to the reduced crosslink density. The mechanical properties of the COPUU networks are tunable over a broad range (either as elastomers or as plastics) depending on the APD component inputs. The tensile strength, Young's modulus and elongation at break for COPUU composed of CO/APD (W/W, 7:3) were improved by 11.7, 2.7 and 5.2 times, respectively, compared to the control CO-based polyurethane without APD. The COPUU can be reprocessed though thermal compression molding and the mechanical properties recovered completely after reprocessing at 180 °C for several cycles. The stress relaxation of COPUU accelerated with increasing APD content due to the increasing concentration of exchangeable disulfide linkage.

蓖麻油（CO）衍生的聚氨酯网络由于具有柔性，高度和永久性交联的网络结构而表现出较差的机械性能和不可再加工性。为了克服这些缺陷，我们通过使基于CO的聚氨酯前体与不同量的4-氨基苯基二硫化物（APD）反应，设计和制造了一系列聚（尿烷脲）（PUU）网络。在这项研究中，对COPUU网络的平衡溶胀行为，力学性能，应力松弛和可再加工性进行了详细研究。由于交联密度的降低，溶胀率随APD含量的增加而增加。根据APD组件的输入，COPUU网络的机械性能可在很宽的范围内调节（无论是弹性体还是塑料）。拉伸强度，杨氏 与不含APD的对照CO基聚氨酯相比，由CO / APD（W / W，7：3）组成的COPUU的s模量和断裂伸长率分别提高了11.7、2.7和5.2倍。可以通过热压成型对COPUU进行再加工，并在180°C下进行数次循环再加工后，机械性能完全恢复。随着可交换二硫键浓度的增加，随着APD含量的增加，COPUU的应力松弛加快。