General polystyrene PS lampshade, instrument cover, toy, etc.
Non-brittle rubber high impact polystyrene high impact polystyrene necessities, electrical parts, toys, etc.
Modified polystyrene ABS material acrylonitrile butadiene styrene ABS electrical shell, daily necessities, advanced toys, sporting goods.
AS material (SAN material) acrylonitrile-styrene acrylic acid as (SAN) transparent household utensils, transparent household appliances, etc.
BS(BDS)K special packaging for styrene butadiene BS(BDS), food containers, pens, etc.
ASA acrylic acid styrene acrylic acid copolymer ASA is suitable for making shells, outdoor furniture and automobile exterior rearview mirrors in general construction fields.
Polypropylene PP packaging bag, drawing, packaging, daily necessities, toys, etc.
Chlorinated polypropylene PPC daily necessities, electrical appliances, etc.
Polyethylene LDPE (flowers, pipes) Low density polyethylene LDPE packaging plastic bags, plastic flowers, plastic bottles, wires, packaging materials, etc.
HDPE HDPE packaging, building materials, buckets, toys, etc.
Modified polyethylene EVA (rubber rubber) ethylene-vinyl acetate EVA soles, films, plates, pipes, daily necessities, etc.
The most outstanding feature of polypropylene is its versatility, which can be applied to a variety of processing methods and uses. Its value and versatility mainly come from its excellent chemical resistance, the lowest density and the highest melting point among all thermoplastics, and moderate cost.
1. Chemistry and properties
Polypropylene (PP) is different from polyethylene PE because the former has a methyl group every other carbon atom, which plays a role in the hardening chain. Unless these methyl groups are on the same side of the chain, the polymer will not crystallize. Before Natta and Ziegler developed stereospecific catalysts (independent of each other), only soft and cohesive random polypropylene could be produced. Source and crystallinity of hardness and solvent resistance of commercial plastics. The chain of PP is harder than PE, so PP has higher melting temperature and tensile strength, but lower crystallinity. The melting point of PP homopolymer is around 330? , depending on the heating speed and thermal history.
When ethylene (random poly) is inserted into PP chain at intervals, the polymer chain will become more irregular and soft, thus reducing the crystallinity, modulus, melting point and melting point sharpness of * * * polymer. Typical random polymers are relatively transparent, with a melting point of 293-305? Within range. When the ethylene content increases, the crystallinity of the polymer becomes lower and lower, and finally it becomes ethylene-propylene rubber (EPR).
Another important polymer is impact-resistant heterogeneous polymer. These products are made of rubber (sometimes polyethylene) polymerized in a homopolymer matrix. The rubber used is usually EPR, which produces a phase state separated from the homopolymer matrix and forms a foggy translucent appearance. These materials are not real block polymers, because the rubber phase can be extracted by solvent. Similar products can be obtained by mixing EPR and PP***, and the melting point of impact-resistant polymer is close to that of homopolymer.
Molecular weight and molecular weight distribution are very important in PP processing. At 446? And 4.75 pounds. Is the index of melt viscosity, which is related to the weight average molecular weight. The melt flow of commercial polypropylene ranges from as low as 0.25 g/10 minute to as high as 800 g/10 minute. The molecular weight distribution is expressed by the ratio of weight average molecular weight to number average molecular weight, and the ratio of high crystallinity PP can be as high as11; PP used as meltblown fabric can be as low as 2. 1. This ratio is very important in the process of fiber spinning, and it also affects the internal stress and orientation process of extrusion swelling.
Like most polymers, polypropylene oxidizes, especially during melt processing. In the case of PP, free radicals attacking tertiary hydrogen are removed to protect the polymer. For PP used for a long time at high temperature, a complex multi-component stabilizer system is adopted; The stabilization system is relatively simple for situations where odor or taste is limited. If it is used to prevent sunlight (ultraviolet rays), carbon black can be added or special stabilization methods can be adopted.
Polypropylene resin and its development
Polypropylene resin is one of the fastest growing thermoplastic resins, and its output has surpassed that of polyethylene and polyvinyl chloride at present.
The main use of polypropylene in the world is to produce injection-molded products, among which commodity turnover box is its main use; Because of its low density and good mechanical properties, it is also widely used in automobile parts. In addition, polypropylene accounts for a large proportion in fibers and films.
From 65438 to 0999, the world consumption of polypropylene was about 26.5 million tons. China is the third largest consumer of polypropylene in the world.
The largest consumption areas of polypropylene in China are woven bags, packaging bags and binding ropes, accounting for about 50%~60% of the total consumption of polypropylene. Another major consumption area of polypropylene in Chinese mainland is film, accounting for about 13%, among which BOPP film is the main one.
China has always been a big importer of polypropylene, and the domestic equipment capacity can't meet the market demand. 1999, the apparent consumption of polypropylene in China was about 4 1 1. 1000 tons, and the output reached 2.647 million tons. The self-sufficiency rate increased from 57.7% in 1998 to 64.4% in 1999, which was mainly related to 199.
Among the 70 polypropylene production enterprises in China, there are 23 in sinopec group and 9 in China Oil and Gas Group/KLOC-0. Among the 3 million tons of polypropylene production capacity in China, sinopec group accounts for 66.7%, and China Petroleum and Natural Gas Corporation accounts for 26.7%. In the national output of 2.65 million tons of polypropylene, China Petrochemical Corporation accounts for 73.2% and China Petroleum and Natural Gas Corporation accounts for 23.0%.
During 2000-2005, several sets of polypropylene production plants will be put into operation in China. It is estimated that by 2005, the production capacity of polypropylene will reach 4 million tons/year, and the apparent consumption is estimated to be about 6.2-6.5 million tons. By 20 10, the apparent consumption of polypropylene is expected to be 8.3-8.4 million tons.
It is predicted that by 2005, the proportion of woven products in China's polypropylene consumption market will decrease, the tensile material market will turn to saturation, and the gap between supply and demand in the special material market will be greatly expanded, and * * * polymer-injected plastics will replace tensile materials as the varieties with the biggest gap between supply and demand; BOPP film materials and cast polypropylene materials have developed rapidly due to the rapid development of packaging industry, and the gap between supply and demand has further widened; Fiber materials have gained new market opportunities due to the development of geotechnical materials, and the demand has increased rapidly, and the gap between supply and demand has widened.
Two confusing nouns:
LLDPE is a linear low density polyethylene, which is polymerized from ethylene and hexene. LLDPE3224 is a brand of linear low density polyethylene, which is produced by Formosa Plastics in Taiwan Province Province. Every company will give its products a name.
LDF200GG is a brand produced by TITANLENE Company in Malaysia. It is also low density polyethylene, but it is not linear low density polyethylene, which is different from the above polymerization method.