Views: 2361 Author: CREATEKING Publish Time: 2024-09-09 Origin: Site
As we all know, PVC products are widely used in our lives. Compared with materials such as wood and steel, PVC has higher elasticity, cold resistance, smoothness, and a wider range of applications. So why do we need to add plasticizers during the production of PVC? What is its role? I believe this is also something that many people are curious about. This article will detail this material's role, characteristics, and industry applications.
Plasticizer is a polymer material additive used to increase the plasticity and flexibility of plastics and improve their fluidity during molding.
Plasticizers are usually some high-boiling, non-volatile viscous liquids or low-melting solids. They do not react chemically with plastic resins, but physically change the physical properties of plastics.
The use of plasticizers can significantly improve the processing performance of plastics, and enhance their flexibility and tensile properties while reducing production costs and improving production efficiency.
There are many types of plasticizers, including aliphatic dibasic acid esters, phthalates, polybenzoates, benzoates, polyol esters, chlorinated hydrocarbons, epoxy resins, citrates, polyesters, etc. Among them, phthalates are one of the most common plasticizers, such as di(2-ethylhexyl) phthalate (DEHP).
The main characteristics of plasticizers are good compatibility, high plasticizing efficiency, good durability, good light and heat stability, good cold resistance, and other special properties.
1. Plasticizer for soft products, used in places with high thermal stability requirements
2. Improve impact resistance and improve the fluidity of rigid PVC products
3. Good compatibility with most resins and liquid plasticizers
4. Better thermal stability compared with liquid plasticizers
5. Excellent low-temperature impact resistance
6. Can retain fillers
7. Chemical resistance and biodegradability
8. High strength
9. Easy to process
10. Better flexibility at low temperatures
11. Better physical properties after thermal aging
12. Better original color after thermal aging
13. Better flexibility when exposed to chemicals
In PVC (polyvinyl chloride), the role of plasticizers is to increase the flexibility and ductility of PVC and improve its processing performance and durability. Since PVC itself is a hard and brittle material, plasticizers can make PVC softer and give it a certain elasticity and plasticity.
1. Increase the flexibility of polymers
Plasticizers can penetrate the PVC molecular chain, and reduce the mutual attraction between molecules, thereby lowering the glass transition temperature of PVC, increasing its softness and flexibility, making PVC easier to bend, stretch, and shape, and adapt to different application requirements.
2. Improved processing performance
Plasticizers can reduce the melting point and viscosity of PVC, improve its melt fluidity, and make PVC easier to process and shape. Plasticizers can reduce the melt viscosity of PVC, improve its melt fluidity, and facilitate processing such as injection molding, extrusion, and calendering.
3. Increased durability
Plasticizers can improve the aging resistance, weather resistance, and chemical resistance of PVC products. Plasticizers can improve the UV resistance of PVC and slow down its aging speed; they can also improve the corrosion resistance of PVC to chemical substances.
Plasticizers are widely used in many industries, including plastic products, rubber, plastic films, degradable plastics, polymer materials, chemical materials, automobile manufacturing, electronic appliances, nanomaterials, aviation, aerospace, food hygiene, coatings and adhesives, textile printing and dyeing, papermaking, inks, cleaning agents, cosmetics, leather, detergents, etc.
1. Soft PVC products
Soft PVC products are widely used in hoses, cables, films, and other fields, mainly relying on plasticizers to improve their flexibility and plasticity.
Common types of plasticizers include phthalates, aliphatic dibasic acid esters, and new environmentally friendly plasticizers. These plasticizers reduce the interaction between PVC molecular chains, making the material soft and not easy to bend at low temperatures.
Plasticizers have a significant effect on the physical and mechanical properties of soft PVC products, including improving their tensile strength, ductility and tear resistance, while ensuring that there are no brittleness, cracking, and other problems during use.
Therefore, choosing the right type and amount of plasticizer is the key to ensuring that soft PVC products achieve the expected performance.
2. Rigid PVC products
Rigid PVC products are usually used in places with high requirements for strength and rigidity, such as pipes, door and window frames, etc. Although rigid PVC has the characteristics of high hardness and good durability, in some applications, a small amount of plasticizer is still needed to improve its impact resistance and crack resistance.
Adding a small amount of plasticizer can effectively improve the toughness of rigid PVC, reduce the brittleness of the material at low temperatures or under force impact, reduce the risk of cracking, and maintain its basic structural strength and rigidity.
This modification effect makes rigid PVC products more durable and safe in practical applications, especially in places where the external environment changes greatly.
3. Application in medical devices
In medical devices, the application of plasticizers in medical-grade PVC is crucial, especially when manufacturing products such as infusion tubes and blood bags, where plasticizers can give PVC materials the required flexibility and durability.
However, medical-grade PVC products have strict biocompatibility and safety requirements for the selection of plasticizers. The plasticizers used must be non-toxic, low-volatile, non-carcinogenic, and will not release harmful substances or cause allergic reactions when in contact with blood or drugs to ensure patient safety and the reliability of medical devices.
4. Application of plasticizers in building materials
In building materials, plasticizers are widely used in products such as PVC flooring, wall panels, doors, and windows to enhance the flexibility and durability of these materials.
By adding plasticizers, PVC building materials can better resist wear, cracking, and aging, extending their service life.
In addition, the use of plasticizers also makes PVC materials easier to cut, shape, and install during construction, greatly improving the convenience of construction.
These improvements ensure the long-term performance of building materials and also improve overall construction efficiency, making PVC materials a popular choice in the construction industry.
1. Add plasticizer in the appropriate amount
When the amount of plasticizer added is less than 10 parts, it has little effect on the mechanical strength of the product. When the amount added is about 5 parts, the mechanical strength of the product is relatively high. This is the so-called anti-plastic phenomenon. Therefore, if the mechanical strength of the product is required to be relatively high, a small amount of plasticizer can be added instead of a large amount of plasticizer.
2. Pay attention to the compatibility of plasticizers and resins
Good plasticizers have good compatibility with resins. If the compatibility is not good enough, the plasticizer will separate from the resin. Plasticizers can generally improve the plasticity of the resin and affect the quality of plastic products.
3. Add a small amount of plasticizer to wire and cable materials
Wire and cable products need to be flame retardant, and good plasticizers need to be added. In addition, adding plasticizers to the main raw materials will reduce the electrical insulation performance of the product. The less plasticizer added, the better.
The importance of plasticizers in PVC products cannot be ignored. By changing the physical and chemical properties of PVC, it changes the material from rigid to flexible to meet the needs of different application scenarios.
Plasticizers not only give soft PVC products such as hoses, cables, and films excellent flexibility and ductility but also improve the impact resistance and crack resistance of rigid PVC products.
In the fields of medical devices, building materials, etc., plasticizers can not only improve the durability and construction convenience of PVC products but also meet strict biocompatibility and safety requirements.
Therefore, the selection and use of plasticizers are directly related to the performance, application breadth, and safety of PVC products, and are key factors in determining the versatility and wide application of PVC materials.
