Synthesis of Tough and Hydrophobic Polyamide 6 for Self-Cleaning, Oil/Water Separation, and Thermal Insulation

The growing demand for polymeric materials has encouraged industries and the academic community to develop materials with improved mechanical properties, particularly those that can be used in various fields. Polyamide 6 (PA6) is a versatile engineering plastic material with various advantageous properties; however, improving its toughness and hydrophobicity is conducive to expanding its application. In this work, α, ω-aminopropyl-terminated poly(methyltrifluoropropylsiloxane) prepolymer (APMFS) was synthesized for its outstanding flexibility and hydrophobicity. It was then covalently incorporated into a PA6 backbone through straightforward large-scale melt polymerization. The functionalized PA6 exhibited the highest breaking strength and toughness of approximately 59.6 MPa and 426.3 MJ/m3, respectively. Moreover, the impact strength of PA6-APMFS reached 63.7 kJ/m2, more than twice that of conventional PA6. The water contact angle was measured at its highest, 94°, with water absorption reduced to 0.5 wt %. Microfibers exhibited a very low wicking height of 7.5 cm. Subsequently, functionalized nanofibrous membranes and foams were applied for self-cleaning, oil/water separation, and thermal insulation, showcasing excellent potential for protective and water purification applications. This work illustrates the multifunctional application advantages of modified PA6.