Research on Improving Hydrophilicity of Polyimide Plasma Treatment

• Categories:Technical Support
• Author:plasma cleaning machine-surface treatment equipment-CRF plasma machine-Sing Fung Intelligent Manufacturing
• Origin:
• Time of issue:2021-05-19
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(Summary description)Research on improving hydrophilicity of polyimide plasma treatment:         Polyimide (P84) fiber has good mechanical properties, radiation resistance, thermal stability and non-combustibility, and can be widely used in some special environments, such as fire protection, electronic aerospace and industrial production. Because polyimide (P84) fiber is limited by its surface structure chemical inertness and surface energy, its poor adhesion affects its reinforcing effect in composite materials. Low-temperature plasma surface modification methods can be used to overcome this shortcoming of fibers.         Plasma is a gas composed of high-energy charged particles and neutral particles. Plasma surface modification only occurs on the surface of the material and does not affect the body of the fiber, so that the fiber can fully improve its surface performance while maintaining its own excellent overall performance.         Through low-temperature plasma surface treatment, the surface of the material undergoes multiple physical and chemical changes, or is etched and rough, or forms a dense cross-linked layer, or introduces oxygen-containing polar groups to make the hydrophilic adhesiveness dyeable Performance, biocompatibility and electrical properties have been improved.         Comparing the surface of the P84 fiber before and after the treatment, it is found that the surface of the untreated fiber is smooth, while pits appear on the surface of the P84 fiber after the low-temperature plasma treatment. This is because particles such as ions and electrons excited molecules or atoms in the plasma sputter and etch the fiber surface. The chemically active substances in the plasma cause oxidative degradation and other reactions on the surface of the material to cause chemical micro-etching.         Under the simultaneous action of the two etchings, pits are formed on the surface of the P84 fiber, and convex deposits are generated at the same time, thus increasing the micro-roughness of the fiber surface. After low-temperature plasma modification, the relative content of N and O elements on the surface of P84 fibers increased significantly. The relative content of C element decreased, and the O/C ratio rose from 25.79% to 27.32%, which indicated that oxygen-containing groups were added on the fiber surface.         Plasma treatment produces unsaturated bonds and free radicals on the surface of polyimide (P84) fibers. These unsaturated bonds and free radicals interact with oxygen in the air to generate new oxygen-containing polar groups, thereby making P84 fibers The chemical composition of the surface changes.         After plasma treatment, the surface of polyimide (P84) fiber undergoes oxidation reaction, and hydrophilic polar groups are introduced into the fiber surface. Enhance the moisture absorption and moisture conduction performance. This is because when low-temperature plasma particles bombard the surface of the polyimide (P84) fiber, the surface will undergo processes such as etching, cross-linking and oxidation, thereby introducing a large number of hydrophilic groups. The presence of hydrophilic groups greatly enhances the moisture absorption capacity of the fiber surface; at the same time, the surface area of ​​the polyimide (P84) fiber after low-temperature plasma treatment increases the surface area, which further improves the moisture absorption and moisture conduction performance.