Fabrication And Performance Of Poly(ether Ether Ketone)fiber-based Thermally Conductive Composites

With the rapid development of industrial technology,electronic products are also advancing in the direction of smaller size and higher power density,which not only increases efficiency but also bring the thermal dissipation issue along with it resulting to reduced service life and operation stability.Traditional heat dissipation materials have disadvantages such as high-density and difficulties to adapt to complex environments.Therefore,choosing the right materials to achieve effective heat management is the key to technological progress in the electronics industry.The polymers matrix is light-weight,cheap,easily processed and excellent chemical stability,thus widely utilized in many fields.Poly ether ether ketone（PEEK）is super engineering plastics with excellent comprehensive performance,but its thermal conductivity is poor,only 0.25 W/m·K which restricts their applications for thermal management materials in electronics field.The economical and effective method to enhance the TC of polymer is to embed thermally conductive fillers into the polymer matrix.In this work,in order to improve the interface compatibility between PEEK matrix and filler aminated PEEK fiber is used as the carrier for the filler orientation,while acylated graphene（GO-COCl）and carboxyl multi-walled carbon nanotubes（MWCNTs-COOH）are selected as filler,respectively.The thermal conductive composites are fabricated by easy and efficient method where the oriented thermal conduction pathway is constructed and the thermal resistance of the interface is reduced.The influence of filler content,distribution state and preparation process on the properties of composite materials were studied systematically.The composites have excellent performance and good heat management ability.The main research includes as follows:1.GO was obtained by oxidation of flake graphite and then acylated（GO-COCl）,while PEEK fiber is nitrificated and then reduced to aminated PEEK（PEEK-NH₂）.GO-COCl is oriented and grafted on the surface of the fiber.PEEK-based composites with high heat conductivity are obtained by vacuum heat molding.With the increase of filler loading,the thermal conductivity of composites increases.When the GO-COCl filler reaches 20 wt%,the thermal conductivity of the composites reaches to 1.202 W/m·K,which is 4.81 times higher than that of pure PEEK.2.PEEK fibers were coated with hydrolyzed KH550 solution uniformly to obtain MPEEKF fiber.Then MWCNTs-COOH were grafted on the MPEEKF fibers to form oriented structure.CNT/MPEEKF composites with oriented structure were prepared by vacuum heat molding.The amount of KH550 is optimized to be 5 vol%to obtain the preferred thermal conductive properties.With the increase of filler loading,the thermal conductivity of composite materials increases.When the content of MWCNTs-COOH is 25 wt%,the through-plane and in-plane thermal conductivity increased to 0.708 and1.904 W/m·K,respectively,which is 2.8 and 7.6 times higher than the pure PEEK.The in-plane thermal conductivity for the composites without KH550 modified PEEK fiber is only close to 0.643 W/m·K in the same filler loading which confirms that interphase interaction enhances between modified PEEK fiber and MWCNTs and interphase heat resistance reduces resulting from the formation of specific thermal conduction paths.The research provides new ideas and strategies for PEEK-based thermal conduction composites.