Nitrile rubber (NBR) is a common raw material for the production of chemicals, with excellent resistance to oil, high temperature, chemical corrosion and other properties, widely used in automotive, aerospace, petrochemical and other fields. This paper will introduce the manufacturing method of NBR.
I. Raw material preparation
1. Butadiene: Butadiene is the main monomer for the preparation of NBR, which is usually produced by naphtha cracking.
2. Acrylonitrile: Acrylonitrile is another main monomer for the preparation of NBR, which is produced by propylene oxidation method.
2. Emulsion polymerization
1. Formulation adjustment: according to the required product properties, mix butadiene and acrylonitrile in a certain proportion, add emulsifier, initiator and other additives, adjust pH to the appropriate range.
2. Polymerization reaction: Pump the mixed monomers into the polymerization kettle and carry out emulsion polymerization reaction under the action of initiator. Temperature, pressure and stirring speed need to be controlled during the reaction to ensure the smooth progress of the reaction.
3. Degassing and dehydration: After the polymerization reaction, the emulsion is degassed and dehydrated to remove unreacted monomer and water.
3. Post-treatment
1. Coagulation: Add coagulant to the emulsion after degassing and dehydration to make the rubber particles coagulate into lumps and precipitate water.
2. Washing and drying: Wash the coalesced rubber block with water to remove the residual emulsifier and salt, and then dry it.
3. Vulcanization: Vulcanize the dried rubber block to improve its physical properties and chemical stability.
4. Quality inspection and packaging
1. Quality inspection: carry out quality inspection on the vulcanized NBR, including appearance, hardness, tensile strength, tear strength and other indexes.
2. Packing: Pack the qualified NBR according to requirements for transportation and storage.
Through the above steps, nitrile rubber with excellent performance can be manufactured. During the production process, each process parameter needs to be strictly controlled to ensure product quality and yield. At the same time, the maintenance and upkeep of the production equipment should be strengthened to improve the operation rate of the equipment and reduce the production cost. In terms of environmental protection, it should strengthen the treatment of wastewater, waste gas and other pollutants to realize green production.
In conclusion, the manufacturing method of NBR involves a number of links and process parameters, which requires producers to have rich experience and skills. By continuously optimizing the production process and improving the technical level, the quality and output of NBR can be further improved, providing more high-quality raw materials for the development of related fields.
