Poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) is a high-performance commercial thermoplastic polymer that exhibits cocrystalline phases (CC) with many low molecular mass guest molecules as well as nanoporous crystalline (NC) phases. In this paper, preparation and characterization, mainly by WAXD and FTIR techniques, of PPO films exhibiting the CC phase with carvacrol (a relevant natural antimicrobial) are reported. The study shows that the relative intensities of two O–H out-of-plane deformation peaks (at 698 and 717 cm⁻¹) of carvacrol are highly sensitive to its concentration in CC films. The reported data can be rationalized by assuming that 698 and 717 cm⁻¹ peaks are due to isolated and hydrogen-bonded guest molecules, respectively, and by preferential inclusion of carvacrol in the cavities of the NC phase. Polarized FTIR spectra of axially stretched CC PPO/carvacrol films show that the guest peak at 717 cm⁻¹ is not dichroic, while the guest peak at 698 cm⁻¹ is markedly dichroic. This confirms that the O–H out-of-plane deformation peak at 698 cm⁻¹ is due to isolated guest molecules, which are mainly enclosed in the cavities of the axially oriented CC phase.

聚（2,6-二甲基-1,4-亚苯基）氧化物 (PPO) 是一种高性能的商业热塑性聚合物，具有共晶相 (CC) 与许多低分子量客体分子以及纳米多孔结晶 (NC) 相。在本文中，主要通过 WAXD 和 FTIR 技术制备和表征了具有香芹酚（一种相关的天然抗菌剂）的 CC 相的 PPO 薄膜。研究表明香芹酚的两个 O-H 平面外变形峰（698 和 717 cm ^-1）的相对强度对其在 CC 膜中的浓度高度敏感。通过假设 698 和 717 cm ^-1峰分别是由于分离的和氢键结合的客体分子，以及香芹酚优先包含在 NC 相的空腔中。轴向拉伸的 CC PPO/香芹酚薄膜的偏振 FTIR 光谱表明，717 cm ^-1处的客体峰不是二向色性的，而 698 cm ^-1处的客体峰是明显的二色性。这证实了 698 cm ^-1处的 O-H 面外变形峰是由于孤立的客体分子，其主要封闭在轴向取向的 CC 相的空腔中。