PVC is the biggest feature of general-purpose plastics. It has a wide range of uses and naturally has its irreplaceable characteristics. Today, the editor will talk about “the use of PVC sheets and the characteristics of PVC materials”.
1. The use of PVC sheet
The pvc material board is a kind of board made of pvc material, which belongs to a kind of more commonly used decorative materials.
A. PVC sheet transparent board: transparent board is processed by adding better auxiliary raw materials on the basis of PVC sheet, with various colors, including white, brown, royal blue and other colors. This kind of board is mainly used in various parts of equipment guards, house decoration, and instrument liquid level display.
B. PVC soft board: it is a board with a softer surface, bright in color, and high-grade raw materials are used to make it exquisite and delicate. Mainly used for train or car decoration, it can also be used as an insulating cushion, and it is also a very good auxiliary material.
C. In addition to the above two uses, pvc sheets are now widely used in chemical or industrial processing equipment and environmental protection equipment. It is often used even in the decoration and communication industries.
2. PVC material characteristics
PVC is one of the most produced varieties in general plastics, and its use is extremely wide, and naturally has its irreplaceable characteristics.
A. PVC chemical properties
PVC contains as much as 58% Cl, so it has extremely high flame retardancy (its oxygen index is as high as 43.6), is insoluble in water, alcohol, gasoline, gas, and has low water vapor leakage; it can withstand any concentration at room temperature Hydrochloric acid, less than 90% sulfuric acid, 50-60% nitric acid and less than 20% caustic soda solution, has certain resistance to chemical corrosion; it is quite stable to salts, but can be dissolved in ethers, ketones, chlorinated aliphatic hydrocarbons and aromatics Organic solvents such as hydrocarbons. In addition, due to the presence of the side group Cl, the light and thermal stability of PVC is poor. It will decompose to produce hydrogen chloride at a temperature above 100°C or after long-term sunlight exposure, and further autocatalyze decomposition and discoloration, resulting in rapid physical and mechanical properties. decline. Industrial PVC resin is mainly amorphous structure, that is, amorphous structure, but it also contains some crystalline regions (about 5%-10%), so PVC has no obvious melting point.
B. The mechanical properties of PVC
(1) The influence of different molecular weights on performance
PVC has good mechanical properties, chemical resistance and flame resistance, and is widely used in various fields of plastic products. Various requirements for plastic products are often not met by modification alone, prompting PVC manufacturers to develop PVC resins with different molecular weights (polymerization degrees) to meet market needs. Resins with different degrees of polymerization often have different properties, which are the most basic factors affecting processing and use characteristics. Regarding the impact of PVC with different molecular weights on performance, the study found that as the degree of polymerization of the PVC resin increases, impact strength, breaking strength, elongation at break and other mechanical properties increase, the yield strength decreases.
(2) Mechanical properties of PVC filled with filler
Filling modification is the most basic method of PVC modification, such as talc, calcium carbonate, calcined kaolin, barium sulfate, white carbon black, coal ash, red mud, etc. can all be used as filling modifiers for PVC. Other fillers have similar effects on PVC filling.
(3) Mechanical properties of PVC toughened by toughening agent
PVC commonly used toughening agents include ABS, CPE, MBS, EVA, ACR, NBR, etc. Among these commonly used toughening agents, other toughening agents blended with PVC have the same effect. They all improve the toughness of the PVC matrix at the same time, resulting in The tensile strength is significantly reduced.