Guo Bingxue, Lou Jinfen, Kuang Tingting, Wang Yanping, Zhang Kai, Qin Jun, He Min, Liu Yufei, Gong Yong-Ji
School of Materials Science and Metallurgical Engineering, Guizhou University Guiyang 550025 China.
National Engineering Research Center for Compounding and Modification of Polymeric Materials Guiyang 550014 China.
RSC Adv. 2025 May 6;15(19):14594-14603. doi: 10.1039/d5ra01209k.
PA6 is widely used but vulnerable to thermo-oxidative aging, impacting its durability. Hindered phenols are key antioxidants that extend the service life of PA6 by slowing this aging process. However, the effect of molecular structural differences on their antioxidant activity is still elusive, impeding their development and application. Here, two antioxidants, 2-((3-(3,5-di--butyl-4-hydroxyphenyl)propionyl)oxy)ethyl acrylate (PEA) and 2-((3-(3,5-di--butyl-4-hydroxyphenyl)propionyl)oxy)propyl acrylate (PPA), were utilized to enhance the thermo-oxidative aging resistance of PA6. Their primary difference is that PPA possesses an electron-donating group in its molecular structure. The methyl functional group in the PPA molecule can increase the electron cloud density around the benzene ring, resulting in PPA having a higher free radical scavenging rate compared to PEA. In addition, in contrast to PEA, the low volatility and mobility of PPA ensure that its antioxidant activity can be fully utilized during aging. These factors collectively support the excellent antioxidant activity of PPA (PPA > PEA). As a result, the PA6/PPA composite maintains 88% of its original tensile strength after 12 days of continuous aging, whereas PA6/PEA and PA6/1010 (commercial antioxidant) composites retained 70% and methyl 30%, respectively. These encouraging findings provide a theoretical basis for the synthesis of antioxidants.
聚酰胺6（PA6）被广泛使用，但易受热氧化老化影响，从而影响其耐久性。受阻酚是关键的抗氧化剂，通过减缓这种老化过程来延长PA6的使用寿命。然而，分子结构差异对其抗氧化活性的影响仍不明确，这阻碍了它们的开发和应用。在此，使用两种抗氧化剂，丙烯酸2-((3-(3,5-二叔丁基-4-羟基苯基)丙酰基)氧基)乙酯（PEA）和丙烯酸2-((3-(3,5-二叔丁基-4-羟基苯基)丙酰基)氧基)丙酯（PPA）来增强PA6的抗热氧化老化性能。它们的主要区别在于PPA在其分子结构中具有供电子基团。PPA分子中的甲基官能团可增加苯环周围的电子云密度，导致PPA与PEA相比具有更高的自由基清除率。此外，与PEA相比，PPA的低挥发性和迁移率确保其抗氧化活性在老化过程中能够得到充分利用。这些因素共同支持了PPA出色的抗氧化活性（PPA > PEA）。结果，PA6/PPA复合材料在连续老化12天后仍保持其原始拉伸强度的88%，而PA6/PEA和PA6/1010（商业抗氧化剂）复合材料分别保留了70%和30%。这些令人鼓舞的发现为抗氧化剂的合成提供了理论依据。
