As a special polymer material, poly (arylene ether nitrile) (PEN) has been widely used in commercial areas. By enhancing the crystalline properties of PEN, it is more conducive to improving its heat resistance, mechanical strength and corrosion resistance. In this paper, a crystalline PEN copolymer was synthesized with the monomers of bisphenol A, hydroquinone and dichlorobenzonitrile by random copolymerization, and the film was cast by a simple casting method. Then the crystalline PEN film was modified by isothermal heat treatment and thermal stretching method. During the heat treatment, the crystallization of the PEN film was researched, and suitable temperature conditions were found for the thermal stretching experiment. During the thermal stretching process, the bisphenol A segment increased the plasticity of the copolymer, promoted crystallization, and improved the overall performance of the copolymer film. The final sample with a stretching rate of 200% had the best overall performance with the thermal decomposition temperature of 5% mass (T_d5%) of higher than 500 °C, the mechanical tensile strength of 197.6 MPa, the dielectric constant of 3.4, the dielectric loss of less than 0.02, and the crystallinity of 34.49%. Besides, the closely arranged spherulites were observed by scanning electron microscope. Therefore, this article provides a new effective way to improve the crystalline properties of the crystalline PEN, and the modified PEN copolymers have potential application value in the fields of high temperature resistance and electronics.

聚（亚芳基醚腈）（PEN）作为一种特殊的高分子材料，在商业领域得到了广泛的应用。通过增强PEN的结晶性能，更有利于提高其耐热性、机械强度和耐腐蚀性能。本文以双酚A、对苯二酚和二氯苯甲腈为单体，通过无规共聚合成了结晶PEN共聚物，并通过简单的流延方法进行流延。然后通过等温热处理和热拉伸方法对结晶PEN薄膜进行改性。在热处理过程中，研究了PEN薄膜的结晶，并找到了适合热拉伸实验的温度条件。在热拉伸过程中，双酚A链段增加了共聚物的塑性，促进结晶，提高共聚物薄膜的整体性能。拉伸率为 200% 的最终样品在热分解温度为 5% 质量 (T_d5% )高于500℃，机械抗拉强度197.6MPa，介电常数3.4，介电损耗小于0.02，结晶度34.49%。此外，通过扫描电子显微镜观察到紧密排列的球晶。因此，本文为提高结晶PEN的结晶性能提供了一种新的有效途径，改性PEN共聚物在耐高温和电子领域具有潜在的应用价值。