端炔基聚丁二烯的固化动力学及性能研究

To develop a non-isocyanate curing system for propellant liner adhesives, a novel alkynyl-terminated polybutadiene (PTPB) was designed and synthesized. Comprehensive structural characterizations were performed using fourier-transform infrared spectroscopy (FT-IR), ¹³C and ¹H nuclear magnetic resonance (¹³C NMR,¹H NMR), and gel permeation chromatography (GPC). The PTPB-based polytriazole liner films were subsequently prepared using glycidyl azide polymer (GAP) as the curing agent via a click chemistry approach. Systematic investigations were conducted to evaluate the influence of both the curing parameter R value and montmorillonite (MMT) addition on the mechanical properties and plasticizer migration resistance of the liners. The synthesized PTPB exhibits a glass transition temperature (T_g) of −80 ℃, a number-average molecular weight (M_n) of 10 653, and its polydispersity index (PDI) of 2.15. Kinetic analysis reveals an apparent activation energy (E_a) of 68.6 kJ·mol⁻¹ and a reaction order (n) of approximately 0.906, enabling accurate simulation of the curing process. Optimal comprehensive mechanical properties, including significantly enhanced tensile strength, were achieved at R = 1.1 with 3 % MMT. Furthermore, the plasticizer migration rate decreased with increasing MMT content. Mechanistic analysis reveals that the PTPB-GAP cross-linked network inhibits migration at the molecular scale through chain entanglement and steric hindrance, while the lamellar structure of MMT extends the diffusion pathway at the nanoscale. These two mechanisms work synergistically to establish a multi-barrier migration suppression system.