Plasticizers are the largest additives in the modern plastics industry and play a decisive role in promoting the development of the plastics industry, especially the PVC industry.
Anything that can be uniformly mixed with resin without chemical change during mixing, but can reduce the glass transition temperature of the material and the melt viscosity during plastic molding processing, and it remains unchanged, or it can be retained in plastic products for a long time despite chemical changes It can change certain physical properties of the resin. Liquid organic compounds or low-melting solids with these properties are called plasticizers.
Performance characteristics of plasticizer:
(1) Excellent compatibility with resin;
(2) High plasticizing efficiency;
(3) Stable to heat and light;
(4) Low volatility;
(5) Small migration;
(6) Resistance to extraction of water, oil and organic solvents;
(7) Good flame retardancy;
(8) Good electrical insulation;
(9) Colorless, tasteless and non-toxic.
The plasticizers used in concrete are also called water reducers, superplasticizers or super plasticizers, which can increase the fluidity and processability of the concrete before it sets, and facilitate construction.
Generally, the higher the water content of concrete, the better its fluidity and workability. But when the concrete has enough water, the strength of the concrete after solidification is inversely proportional to the water content. Therefore, if the concrete is to have high strength, the water content of the concrete should not be too much, and the workability will be worse at this time.
The plasticizer can reduce the water content of the concrete without affecting the workability of the concrete (therefore it is called a water reducing agent). ), it also improves the strength of concrete. If Pozzolana pozzolan is added to the concrete, plasticizers are also added to increase the strength. This method is often used to increase the strength when producing high-strength concrete or fiber reinforced concrete.