As a kind of polymer compound made from monomer and polymerized by addition or condensation polymerization, plastic is widely used. Plastic products can be seen everywhere in our life. Unconsciously, plastic products have become an indispensable and important part of people's life. Also, due to non-degradability, the environmental problems caused by plastic have become the focus of global environmental protection organizations.
(Plastic products in daily life)
The main component of plastic is resin, which can be classified into thermosetting and thermoplastic plastics. According to the different types of synthetic polymers, plastics include polyethylene, polyvinyl chloride, polystyrene, polypropylene, and other types. Different types of plastics determine their usage in life and industry.
Plastics have been widely used mainly because of the following advantages:
Low manufacturing cost;
Most of the plastic has strong corrosion resistance and does not react with acids and bases.
Durable, waterproof, lightweight;
Easily molded into different shapes;
A good insulator;
The plastic usually used is not a single component; it is made from many materials. Among them, macromolecule polymer (or synthetic resin) is the main component of plastic. Also, to improve the performance, all sorts of auxiliary materials should be added in macromolecule compounds, such as filler, plasticizer, lubricant, stabilizer, coloring agent, antistatic agent to form the plastic with good performance.
Among them, adding fumed silica (commonly known as gas-phase silica) into plastics has become an important way to improve the properties of plastics.
The plastic can be densified by using the characteristics of fumed silica including photo permeability and small particle size. For example, adding fumed silica to polystyrene plastic film can not only improve the strength and toughness but also improve the waterproof property and anti-aging property; the hardness, finish and anti-aging property of windows and doors of plastic steel produced by adding a small amount of fumed silica in common plastic PVC are greatly improved; also, modification of ordinary plastic polypropylene is achieved by using fumed silica, with the main technical indexes (water absorption, insulation resistance, compression residual deformation, and flexural strength, etc.) reaching or exceeding the performance indexes of engineering plastic nylon 6. The use of polypropylene railway accessories instead of nylon 6 is realized. Thus, the product cost has been greatly reduced and its economic and social benefits are remarkable.
Fumed silica ( pyrogenic ) is a kind of white fluffy inorganic nano nonmetallic oxide and is also the earliest nanopowder material in large-scale production and the most widely used nanopowder material so far. Widely used in silicone rubber, sealants and adhesives, unsaturated polyester, paint inks, electronic and electrical applications, green tires, construction and aerospace, and other fields. In the plastic products, the fumed silica also has an incomparable effect due to its excellent characteristics.