Modification and application of polypropylene plastic

Modification and application of polypropylene plastics 1. Polypropylene plays an important role in the production of synthetic resins and develops extremely rapidly.

Polypropylene is an important variety among the five general synthetic resins, and its development at home and abroad is very rapid. Among the five major synthetic resins for plastics in the world, polypropylene production accounts for about 1/4 of the total. It is estimated that the total production capacity of the world's five major synthetic resins will reach 190 million tons in 2006, of which 47.78 million tons of polypropylene will account for the total. 25.6% of capacity [1]. In 2004, the output of polypropylene resin in China was 4,784,800 tons, the import was 2.914 million tons, and the export was 15,300 tons. The apparent consumption was 7.647 million tons, accounting for 25.9% of the total consumption of the five general-purpose resins in the country. . It is estimated that by 2010, the apparent consumption of polypropylene resin in China will increase to 10.8 million tons, an increase of more than 40% compared with 2004. Table 1 lists the locations and capacities of polypropylene plants that are currently in production and under construction. Table 1 Recent production and construction of polypropylene plants [life latitude and longitude] Construction site capacity (10,000 tons)
Daqing Refinery 30 has been put into operation
Shanghai Secco 25 has been put into production
Beijing Yanshan 12 was successfully renovated and expanded
Lanzhou Petrochemical 30 has started
Fujian Refining & Chemical 40 has started
Maoming Petrochemical 30 under construction
Dalian Petrochemical 40 is under construction
Ningxia Petrochemical, Shandong Hengyuan Petrochemical 10 under construction
Fujian Quangang 15 under construction
Zhejiang Shaoxing 10 under construction
Guangzhou Petrochemical 30 put into operation before 2009
Formosa Plastics Ningbo 45 put into operation before 2007
Zhenhai Refining & Chemical 20 started production before 2007
Beijing Yanshan Expansion 38 put into operation before 2009
Tianjin Petrochemical 55 put into operation before 2008
Inner Mongolia Baotou 30 under construction
Inner Mongolia Duolun 46 under construction
Northeast Dalian, Fushun and other places 136 under construction
Dushanzi Petrochemical 55 Reconstruction and Expansion
Among the announced new capacity, Sinopec 2.53 million tons / year, PetroChina 1.35 million tons / year, and most projects have a capacity of more than 300,000 tons, reaching a world-class scale. After all of these devices are put into production, Sinopec's polypropylene production capacity will exceed Basel, ranking first in the world, and PetroChina will rank among the top five. By then, China will become the world's largest producer of polypropylene resin. According to another report, the output of polypropylene resin in China was only 1.0733 million tons in 1995, reaching 5.229 million tons in 2005, with an average annual increase of 38.7%. The apparent consumption during the same period increased from 2,212,200 tons to 8.23 ​​million tons. It has increased by 28.7%, becoming the fastest growing country in the world for polypropylene consumption [2].

1 Basic knowledge of polypropylene

1.1 Resin and plastic definition and classification Resin: Polymer materials are also called high molecular polymers, which are divided into natural polymer materials and synthetic polymer materials. In synthetic polymer materials, plastic, rubber and fiber are divided into three major categories: synthetic resin, synthetic rubber and synthetic fiber. Among them, synthetic resin used in plastics accounts for the largest proportion, accounting for 2% of total synthetic materials. /3 or more. Plastics: A material that has a synthetic resin as its main component, an appropriate amount of fillers, auxiliaries, and pigments, and which can flow and form during processing. ThermoPlastics: A plastic that hardens and cools hardened repeatedly over a specified temperature range. Thermosetting Plastics: Plastics that become infusible, insoluble materials after the first molding. General Plastics: refers to plastics with large output, wide application, good molding performance and relatively low price. The plastics based on the five general-purpose resins are polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and acrylonitrile-butadiene-styrene (ABS). . Engineering Plastics: refers to plastics that have high performance and can be used as engineering structural parts. Engineering plastics are further divided into general engineering plastics and special engineering plastics. The former are such as polyamide (PA), polyoxymethylene (POM), polyester (PET and PBT), polycarbonate (PC), modified polyphenylene ether (MPPO). The use temperature is generally below 150 ° C, and special engineering plastics refer to engineering plastics with a temperature above 150 ° C, such as polysulfone (PSF), polyphenylene sulfide (PPS), polyimide (PI), Polytetrafluoroethylene (PTFE), etc.

1.2 Types and characteristics of polypropylene (PP)

2.2.1 Basic concept of polypropylene Polypropylene is a polymer obtained by polyaddition reaction of propylene (CH3-CH=CH2) as a monomer. The reaction characteristics are instantaneously completed, and the second is that there is no small molecule compound. produce. A high molecular weight crystalline PP can be obtained by using a Ziegler-Natta catalyst. According to the law of the arrangement of the CH3 group in space, PP is divided into three kinds of polymers: isotactic, syndiotactic and random. Only a highly isotactic PP can produce a good crystallization zone in order to have the excellent properties we need. The crystal form of isotactic polypropylene is α, β, γ, δ and quasi-hexagonal, the most common being α-crystalline, belonging to monoclinic system. The α crystalline state is formed at about 138 ° C and has a melting point of 180 ° C. The pseudo-hexagonal state is also called the sub-crystal structure, also known as butterfly liquid crystal. When the isotactic PP in a molten state is quenched to below 70 ° C or cold-drawn at 70 ° C or lower, pseudo hexagonal crystals are formed.

Summer Short Sleeves: