Alentiev Alexander Yu, Levin Ivan S, Belov Nikolay A, Nikiforov Roman Yu, Chirkov Sergey V, Bezgin Denis A, Ryzhikh Victoria E, Kostina Julia V, Shantarovich Victor P, Grunin Leonid Yu
A.V. Topchiev Institute of Petrochemical Synthesis RAS, 119991 Moscow, Russia.
N.N. Semenov Federal Research Center For Chemical Physics RAS, 119991 Moscow, Russia.
Polymers (Basel). 2021 Dec 29;14(1):120. doi: 10.3390/polym14010120.
Poly-2,6-dimethylphenylene oxide (PPO) film samples with varying degrees of crystallinity (from 0 to 69%) were obtained by means of different techniques. The films were studied by various physicochemical methods (Fourier-transform infrared spectroscopy, positron annihilation lifetime spectroscopy, X-ray diffraction, and H nuclear magnetic resonance relaxation). Solubility coefficients of gases in the PPO samples were measured via sorption isotherms of gases by volumetric technique with chromatographic detection. The apparent activation energy of permeation and the activation energy of diffusion of all gases were estimated based on temperature dependences of gas permeability and diffusivity for amorphous and semi-crystalline PPO in the range of 20-50 °C. The peculiarities of free volume, density, and thermal properties of gas transport confirm the nanoporosity of the gas-permeable crystalline phase of PPO. So, the PPO can be included in the group of organic molecular sieves.
通过不同技术获得了具有不同结晶度（从0到69%）的聚-2,6-二甲基苯醚（PPO）薄膜样品。采用多种物理化学方法（傅里叶变换红外光谱、正电子湮没寿命光谱、X射线衍射和氢核磁共振弛豫）对薄膜进行了研究。通过体积技术结合色谱检测的气体吸附等温线测量了气体在PPO样品中的溶解度系数。基于20-50°C范围内非晶态和半晶态PPO的气体渗透率和扩散率的温度依赖性，估算了所有气体的表观渗透活化能和扩散活化能。气体传输的自由体积、密度和热性能的特点证实了PPO透气结晶相的纳米孔隙率。因此，PPO可归入有机分子筛类别。
