Preparing And Properties Of High Thermal Conductivity POM/Al₂O₃ Composites

With the high-speed development of science, technology and industrial production, the application field of polymer materials is more and more wide.At the same time,the materials’ requirement standards are becoming much higher than before in some special fields.Thermal conductive polymer materials have gained widespread attention of its excellent performances.Therefore,preparing polymer composite materials with well conductivity and good comprehensive properties has very high practical significance.In this paper,POM thermal conductive composites prepared by melt blending method based on polyoxymethylene (POM) resin as matrix, the zinc oxide (ZnO), alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC) as the thermal conductive fillers. The main content:(1)The kind and amount of coupling agent on thermal conductive powder filler, the effects of surface treatment and the properties of composite was studied. Results show that the use of titanate coupling agent YDH-201 has best effect at 1.5% dosage. Thermal conductive composites’ thermal conductivity and compatibility have been improved better than others. (2)We studied the effect on thermal properties and mechanical properties of composites about filler type, size of fillers and filler content of single component. Through filling two kinds of zinc oxide particles (2μm,4μm) and four different size alumina particles (6μm, 10μm,15μm,30μm) as one-component into POM resin to prepare thermal conductive composite materials.the thermal conductivity of the composites increased with the increase of filler dosage,but its mechanical properties all showed a trend of decrease.At the same time,we also know that the thermal conductivity of POM composite filled 15 microns alumina is highest, due to the alumina of medium size,can be well dispersed in the resin.Material mechanics performances is better also.When the dosage of 65%, thermal conductivity can reach to 1.68 W(m·K)-1, volume resistivity of 3.2×105Ω·cm., the tensile strength 24.0MPa, the bending strength is 42.9 MPa, the impact strength 4.90 kJ/m2. (3) Research of filler compound and the mixed ratio effect on thermal conductivity and mechanical properties of composite materials. Now We mixed 15μm alumina with high thermal conductivity filler aluminum nitride (10μm), silicon carbide (15μm) respectively and added into POM By measuring the thermal conductivity, volume resistivity, melt index, found that the show best performances while Al2O3:AlN at7:3. Thermal conductivity of POM composite reached to 1.791 W(m·K)-’, volume resistivity 1.18×1015Ω·cm, melt index 5.54 g/10 min.