ABS plastic and PVC plastic are two particularly common materials in daily life, and both have their own characteristics. Therefore, many people have a special question when making purchases, which is better, ABS plastic or PVC. The following text will provide you with relevant introductions. At the same time, what are the properties of PVC plastic? Many people can only make better choices after understanding it.
1. These two materials each have their own advantages and disadvantages
2. PVC is polyvinyl chloride, which has good water resistance, ACID and alkali resistance, chemical resistance, and is cheap. The disadvantage is that it has high production technology and special requirements for molds or screws,
ABS has good toughness and strength, good flowability, and easy molding, but its disadvantages are expensive price and poor aging resistance. It starts to change color after one month
3. So now many places use PVC/ABS alloy pellets, combining the advantages of PVC and ABS materials, and the price is also moderate and relatively cheap
What are the properties of PVC plastics?
1. Physical performance
Pvc Resin is a thermoplastic with an amorphous structure. Under ultraviolet light, hard PVC produces light blue or purple white fluorescence, while soft PVC emits blue or blue white fluorescence. When the temperature is 20 ℃, the refractive index is 1.544 and the specific gravity is 1.40. The density of products with Plasticizer and filler is usually 1.15~2.00. The density of flexible PVC foam is 0.08~0.48 and that of rigid foam is 0.03~0.08. The water absorption rate of PVC shall not exceed 0.5%.
2. Thermal performance
The softening point of Polyvinyl Chloride Resin is close to the decomposition temperature. It began to decompose at 140 ℃, and decomposed more rapidly at 170 ℃. In order to ensure the normal processing of PVC Resin, two important process indicators are specified, namely decomposition temperature and thermal stability. The so-called decomposition temperature refers to the temperature at which a large amount of gas is released, and the so-called thermal stability refers to the time when a large amount of gas is not released under certain temperature conditions (usually 190 ℃). Polyvinyl chloride plastic will decompose when exposed to 100 ℃ for a long time, unless alkaline stabilizers are added. If it exceeds 180 ℃, it will decompose quickly.
3. Stability
PVC Resin is a relatively unstable polymer that can also degrade under the action of light and heat. The process involves release and structural changes, but to a lesser extent. At the same time, it will accelerate decomposition in the presence of mechanical force, oxygen, odor, HCl, and certain active metal ions.
4. Electrical performance
The electrical performance of PVC depends on the amount of residue in the polymer, the type and quantity of various additives in the formula. The electrical properties of PVC are also related to the heating conditions: when heating causes PVC to decompose, the presence of chloride ions reduces its electrical insulation. If a large amount of chloride ions cannot be neutralized by alkaline stabilizers (such as lead salts), it will lead to a significant decrease in its electrical insulation performance. Unlike non polar polymers such as polyethylene and Polypropylene, PVC's electrical properties vary with frequency and temperature, such as a decrease in dielectric constant with increasing frequency.
