A modification method of nano-samarium oxide MC nylon

MC nylon is a new type of engineering plastic, which is made of caprolactam as the main raw material by anion polymerization under atmospheric pressure. MC nylon is gradually replacing copper, aluminum, steel and other metal materials and is widely used in textile, rubber, petrochemical, steel rolling, mining machinery, automobile, elevator, crane and other industries. But compared with metal, MC nylon has some disadvantages such as lower strength, modulus and thermal deformation temperature, larger water absorption rate and poor dimensional stability. In recent years, the research on modified MC nylon is active at home and abroad. The common modification methods are mainly carbon fiber or glass fiber reinforcement, inorganic particle filling, copolymerization with other polymers, adding organic matter and so on. There are many methods of toughening and reinforcing plastic, such as blending, copolymerization and toughening agent. Filling the matrix with inorganic fillers usually reduces the cost of the product, improves the rigidity, heat resistance and dimensional stability, but often reduces the impact strength and fracture elongation. Adding elastic rubber particles into rigid plastics can increase impact strength, but decrease tensile strength. The tensile strength of polymer materials can be greatly increased by adding reinforced fibers, but the impact strength, especially the elongation at break, tends to decrease. In recent years, the in-situ composite reinforcement of polymer materials by liquid crystal polymers can improve the tensile strength and impact strength of composites, but the elongation at break still decreases. Traditional modification methods are all at the cost of sacrificing some properties of the material. When the impact toughness of the material is increased, its tensile strength, stiffness and other related properties are decreased, while when the tensile strength and stiffness of the material are increased, its toughness becomes worse. Therefore, the industry is looking forward to a new TYPE of MC nylon and its modification method to overcome the above shortcomings.

1. A nano-samarium oxide modified MC nylon and its modification method, including parent material caprolactam 100 weight parts, nano-samarium oxide 0.5-1.0 weight parts, accelerant sodium hydroxide 0.12-0.2 weight parts, curing agent TDI0.3-0.7 liter, Solid lubricants of molybdenum disulfide, graphite and boron nitride are 2-3 parts, 0.5-0.8 parts by weight and 0.3-0.5 parts by weight respectively, which are characterized by the specific production steps as follows:

(Step 1) Heating the mold: evenly smear the bottom mold and the upper mold with demoulding solution and heat them respectively. When the temperature of the bottom mold is 145℃-180℃ and the temperature of the upper mold is 175℃-220℃, install the upper mold on the bottom mold and start pouring.

(Step 2) Feeding: The base material caprolactam 100 weight into the melting kettle, connect the vacuum tube and measure the temperature, heating the melting kettle, the molten caprolactam below 120℃ began to vacuum, at this time the pressure in the melting kettle is negative pressure 0.08MPA-0.1mpa, close the vacuum pump, open the air valve, unplug the vacuum tube, Inject nano-samarium oxide 0.5-1.0 by weight, accelerant sodium hydroxide 0.12-0.2 by weight, solid lubricant molybdenum disulfide 23 by weight, graphite 0.5-0.8 by weight, boron nitrite 0.3-0.5 by weight, connect the vacuum tube, and then start the vacuum pump to vacuum for no less than 1min. The melting kettle temperature is maintained at 155℃-170℃;

(Step 3) curing molding: inject 0.3-0.7l of curing agent TDI into the activation molecules in the molten kettle and inject it from the pouring port of the mold. At the same time, open the centrifuge and control the centrifuge time in 1-5min. Turn off the power of the centrifuge and open the mold heating box after the centrifuge disk is stationary.

(Step 4) Internal stress treatment: Dip the solidified slider blank into the water heating container and cook it in boiling water for more than 3h:

(Step 5) Mechanical processing: the slider blank processed by internal stress is cooled naturally, and processed and formed according to the technical specifications after the blank temperature is cooled to the ambient temperature.

The invention relates to a nano-samarium oxide modified MC nylon and a modification method thereof, belonging to the technical field of plastics. Including base caprolactam 100 by weight, nano-samarium oxide 0.5-1.0 by weight, accelerant sodium hydroxide 0.12-0.2 by weight, curing agent TDI0.3-0.7 l, solid lubricant molybdenum disulfide, graphite, boron nitrite are 2-3 by weight, 0.5-0.8 by weight, 0.3-0.5 by weight, respectively. Specific production steps for heating mold, feeding, curing molding, internal stress treatment, mechanical processing. This invention can well transfer of external stress, can trigger a matrix yield again, consume a large amount of impact energy, which at the same time increase the effect of this invention product toughness and strength, the present invention adopt the centrifugal casting process technology of products, to eliminate the internal porosity of the product, overcome the steel slider due to its internal defects such as pores and inclusions of product quality problems.

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