Propylene ethylene block copolymer
DATE：2022/12/29 8:36:29 / READ： / SOURCE：This station
2.2.3 Propylene ethylene block copolymer
The propylene ethylene block copolymer is the same as the propylene ethylene random copolymer, but due to the different copolymerization methods and process conditions, the copolymer of propylene and ethylene can be divided into random copolymer and block copolymer. According to the national standard GB 2546-88, the abbreviation code of block copolymer polypropylene is PP-B.
(1) Performance characteristics
The crystallinity of propylene ethylene block copolymer is high, and its performance characteristics are similar to those of isotactic polypropylene, mainly depending on changes in ethylene content, block structure, molecular weight and distribution of copolymer. PP-B generally has higher rigidity and better low-temperature toughness. Compared with propylene ethylene random copolymer, the impact strength is greatly improved and the embrittlement temperature is much lower. Ethylene content in propylene ethylene block copolymer is generally in the range of 5%~20% (mass). When the ethylene content is 2%~3%, the embrittlement temperature is - 35~- 22 ℃. Compared with high-density polyethylene, block copolymer has high heat resistance, good stress cracking resistance, high surface hardness, low shrinkage and good creep resistance.
See Table 2-47 for physical and mechanical properties of propylene ethylene block copolymer. The performance comparison between block copolymer and random copolymer is shown in Table 2-48. See Table 2-49 for properties of propylene ethylene block copolymer produced by Yanshan Petrochemical Company.
(2) Forming method and application
The method of forming plastic products with propylene ethylene block copolymer is the same as that of forming plastic products with isotactic polypropylene. The products can be molded with an extruder, an injection molding machine, or molded with methods such as blow molding and spinning. In addition, the products can also be welded, electroplated, or processed for the second time if necessary. The type of molded plastic products is also the same as that of isotactic polypropylene, but because the toughness and low-temperature performance of propylene ethylene block copolymer are better than that of homopolymer polypropylene, for those polypropylene products that require good toughness for application in low-temperature environment, propylene ethylene block copolymer raw materials should be preferred for processing products. The main products include: industrial accessories, large containers, transport boxes, blow moulded bottles and other hollow containers, extruded cables, pipes and plates, as well as films, composite films and crude fibers. Specific applications can refer to the use of isotactic polypropylene products. There are many domestic producers of propylene ethylene block copolymer, such as Beijing Yanshan Petrochemical Company, Yangzi Petrochemical Company, Liaoyang Petrochemical Fiber Company, Shanghai Petrochemical Co., Ltd., Qilu Petrochemical Company, etc. Generally, any manufacturer that can produce isotactic polypropylene resin can produce block copolymer polypropylene.
The propylene ethylene block copolymer is the same as the propylene ethylene random copolymer, but due to the different copolymerization methods and process conditions, the copolymer of propylene and ethylene can be divided into random copolymer and block copolymer. According to the national standard GB 2546-88, the abbreviation code of block copolymer polypropylene is PP-B.
(1) Performance characteristics
The crystallinity of propylene ethylene block copolymer is high, and its performance characteristics are similar to those of isotactic polypropylene, mainly depending on changes in ethylene content, block structure, molecular weight and distribution of copolymer. PP-B generally has higher rigidity and better low-temperature toughness. Compared with propylene ethylene random copolymer, the impact strength is greatly improved and the embrittlement temperature is much lower. Ethylene content in propylene ethylene block copolymer is generally in the range of 5%~20% (mass). When the ethylene content is 2%~3%, the embrittlement temperature is - 35~- 22 ℃. Compared with high-density polyethylene, block copolymer has high heat resistance, good stress cracking resistance, high surface hardness, low shrinkage and good creep resistance.
See Table 2-47 for physical and mechanical properties of propylene ethylene block copolymer. The performance comparison between block copolymer and random copolymer is shown in Table 2-48. See Table 2-49 for properties of propylene ethylene block copolymer produced by Yanshan Petrochemical Company.
(2) Forming method and application
The method of forming plastic products with propylene ethylene block copolymer is the same as that of forming plastic products with isotactic polypropylene. The products can be molded with an extruder, an injection molding machine, or molded with methods such as blow molding and spinning. In addition, the products can also be welded, electroplated, or processed for the second time if necessary. The type of molded plastic products is also the same as that of isotactic polypropylene, but because the toughness and low-temperature performance of propylene ethylene block copolymer are better than that of homopolymer polypropylene, for those polypropylene products that require good toughness for application in low-temperature environment, propylene ethylene block copolymer raw materials should be preferred for processing products. The main products include: industrial accessories, large containers, transport boxes, blow moulded bottles and other hollow containers, extruded cables, pipes and plates, as well as films, composite films and crude fibers. Specific applications can refer to the use of isotactic polypropylene products. There are many domestic producers of propylene ethylene block copolymer, such as Beijing Yanshan Petrochemical Company, Yangzi Petrochemical Company, Liaoyang Petrochemical Fiber Company, Shanghai Petrochemical Co., Ltd., Qilu Petrochemical Company, etc. Generally, any manufacturer that can produce isotactic polypropylene resin can produce block copolymer polypropylene.
Author：admin