| MC nylon(Monomer casting nylon)is a new kind of engineering plastic, which has the advantage of light quality, good self-lubricating, low noise, good mechanical performance and so on. In recent years, it gradually replaces copper, aluminum, steel and other metal materials in industrial applications. But without modification, MC nylon has some shortcomings, such as low modulus of elasticity, the poor mechanical strength, poor dimensional stability and thermal stability and so on, limiting the practical application of MC nylon. Therefore, there is a need to modify MC nylon in order to improve the comprehensive performances.Molybdenum disulfide is the layer structure compound by stacking of S-Mo-S layers,known as the "king of the lubrication”. It can greatly improve the mechanical properties of composite materials due to its excellent lubrication performance, wear resistance, thermal stability and anisotropy, etc. This paper adopt the molybdenum disulfide as modifying agent to modify the mechanical properties and thermodynamic properties of MC nylon. The main research contents and conclusions are as follows:(1)The preparation of nano-Mo S2: orthogonal experiment design method was adopted to prepare nano-Mo S2, which selected the reaction temperature, reaction time and the amount of silicotungstic acid as the impact factors. The results showed that the best experiment conditions were reaction temperature 200℃, reaction time 24 h, silicotungstic acid addition amount for 1.0 g, for it had the highest production rate 76% and the smallest size. And the biggest impact factor was the reaction time, silicotungstic acid content followed, and last the reaction temperature. XRD and TEM patterns had been used to characterize the crystal structure and morphology of Mo S2. And XRD patterns showed that Mo S2 have good crystal structure, and TEM showed Mo S2 have good uniform nanopartical structure, with most of partical sizes less than 100 nm in diameter. TG patterns showed that nano-Mo S2 has stable thermal stability.(2)nano-Mo S2/MC nylon composites were prepared by in-situ polymerization.and the effects on the thermal stability 、mechanical performance、abrasion performance, and melt crystallization performance with the different addition of nano-Mo S2 were discussed. The results showed that the addition of molybdenum disulfide had greatly enhanced the impact strength and wear resistance of the composite materials. The impact strength has increased by42.3% and the wear volume reduced by 87.4% when the adding amount was 2.0%. In addition, thermal decomposition temperature of MC nylon was much higher than pure MC nylon, greatly promoted the thermal stability of the composites. And the thermal stability of the composites reached its best when the adding amount was 3.0%.In addition, the melt crystallization curves showed that the addition of nano-Mo S2 has promoted the crystallization nucleation process of composite materials and accelerated the crystallization process.(3)Oil Mo S2 / MC nylon composite has successfully prepared by a new method, and the mechanics performance, wear resistance, thermal stability and melting crystallization properties of compound material were discussed.The results showed that oil nano-Mo S2 have greatly improved the notched impact strength and wear resistance of composites. And the notched impact strength reached its maximum value at weight 2.0%, increased by 45.7%compared to pure MC nylon; and wear reaches its minimum volume, reduced by 88.7%compared with MC matrix.(4)Polyether/Mo S2/MC nylon composites were prepared and its mechanical properties along with the different amount of Mo S2 were discussed.The conclusions showed that the impact strength performance and the abrasion performance were greatly enhanced.When adding amount was 2.0%, the notched impact strength is higher than the MC nylon matrix by57%, and the wear volume was reduced by 94.8%. |
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