The nine main categories of plastic additives are welcome.
1, antioxidants (Antioxidant) unsaturated unsaturated bonds in the oxygen by the oxygen atoms, heat and light caused by the invasion of free radicals, resulting in a chain reaction, the molecular chain breaks or the formation of chain cross-linking, resulting in plastic products The strength is reduced or becomes brittle. Antioxidant function is to delay the decomposition of plastic due to oxidation, extend the life of plastic products.
The antioxidants used in the plastics industry can be divided into:
(1) Oxidative chain reaction inhibitors such as Alkyl phenol, Butylated hydroxytoluene BHT, Aromatic amines, Phenyl-B- Naphthylamine, Alkyl Quinone, Alkylene bisphenol, Alkyl phenolthioether, Phenyl salicylate, and the like.
(2) Peroxide decomposers such as thioethanol, thiopropionate, organic phosphites, disulfide and the like.
(3) heavy metal deactivators such as amide compounds, hydrazines, aromatic amine compounds and the like.
2, antistatic agent (Antistatic agent) antistatic agent is the main function of giving plastic to produce electrical conductivity, so as to avoid friction caused by the accumulation of static electricity. Commonly used antistatic agents are quaternary ammonium salts, ethoxylated amines, fatty acid esters and sulfonated waxes.
3, Blowing agent (Blowing agent) plastic foaming agent mainly has three categories:
① nitrogen, carbon dioxide, and air, directly into the plastic melt to make foam;
② volatile liquid such as butane, pentane, petroleum ether, difluorodichloromethane, etc., in the temperature after the expansion of the expansion, leaving the plastic body foam, the common polystyrene foam that belongs to this type;
Decompressive chemical foaming agents, which are generally solid powders that decompose and emit gas (usually nitrogen or carbon dioxide) when heated, causing the plastic to produce a cell-like structure and reduce the weight. These foaming agents are mostly organic azo compounds such as azodicarbonamide and Azobisisobutyro-nitrile (AIBN). Foam plastic are: ABS, PS, PVC, PU, EVA, PE, PP and so on.
4, Flame retardant (Flame retardant) When the addition of flame retardant plastic exposed to the flame, can inhibit the spread of the flame itself, to prevent the formation of smoke, when the flame is removed when the combustion will stop. Plastic flame retardant principle can be divided into three categories:
(1) reactive type (Reactive type) of the flame retardant can react with oxygen to form an inert gas, enveloped in the combustion of the surrounding, reducing the combustion of oxygen content, in order to achieve the purpose of termination of combustion. Any combustion can produce CO, CO2, NH3 and halogen compounds, such as PVC, PU foam, polyester or epoxy resin are selected this method.
(2) non-reactive type (Non-Reactive type) of the flame retardant is a halogen, phosphorus, nitrogen or boron compounds, when the combustion occurs, you can break down an inert, drape the plastic burner surface, The formation of a layer of obstacles to isolate the outside world of oxygen, to achieve the purpose of fire.
(3) waterborne oxides such as alumina flame retardant encountered combustion, can release the water vapor, the combustion process to absorb the heat, so that the temperature around the combustion material to reduce the spread of the flame to prevent the formation of smoke.
5, Lubricant (Lubricant) lubricant can be divided into internal lubricants and external lubricant, the main function of the internal lubricant is to improve the internal mobility of resin, resin molecules to reduce the internal friction, such as fatty acids (hard Fatty acid monoglyceride); the external lubricant reduces the adhesion of the resin to the processing machine and improves the smoothness of the product surface easily, such as Hoechst Wax.
6, impact modifier (Impact modifier) impact resistance modifier is usually a special resin to Compounding (Compounding) way to add, and improve the impact resistance of plastic. Impact-resistant modifiers often affect the heat resistance, fluidity or processability of plastics, and must be carefully chosen.
7, plasticizer (plasticizer) Most of the synthetic resin with plasticity, but the plasticity of the size is not the same, in order to make the resin easy to plasticize and give the product flexibility, generally in the resin by adding some low molecular substances, these low molecular Called plasticizer. Plasticizer is a liquid or low melting point material, and the resin should have good miscibility. Commonly used plasticizers from phthalates, aliphatic dibasic acid esters, phosphates, chlorinated paraffin and so on.
8, coloring agent (coloring agent) is to beautify and decorate the plastic in the material to add the pigment containing additives called coloring agent.
9, filling material (filling material) is added to the plastic batch to reduce costs, and sometimes can enhance the physical properties of plastics, such as hardness, stiffness and impact strength of the relatively inert substances called fillers. The most commonly used fillers are made of clay, silicate, talc, carbonate and the like.
Post time: Sep-05-2017