Causes and solutions for PVC plasticizer precipitation

PVC (polyvinyl chloride) plasticizer precipitation refers to the migration of plasticizers from the inside of PVC products to the surface of products, or even completely volatilization into the surrounding environment. This phenomenon will cause the performance of PVC products to deteriorate, such as hardening, brittleness, loss of elasticity, etc. The following are the causes of PVC plasticizer precipitation and corresponding solutions:

Causes of PVC plasticizer precipitation:

1. Poor compatibility of plasticizer with PVC: If the compatibility of plasticizer with PVC resin is not good, plasticizer is easy to precipitate from the polymer.

2. Excessive plasticizer: The amount of plasticizer added exceeds the maximum capacity that PVC resin can maintain, resulting in excess plasticizer precipitation.

3. Temperature: In a high temperature environment, the volatility of plasticizers increases, and it is easy to precipitate from PVC products.

4. Humidity: In a high humidity environment, some plasticizers may absorb moisture, resulting in reduced stability in PVC products.

5. Ultraviolet radiation: Long-term ultraviolet radiation can destroy the molecular structure of PVC, resulting in plasticizer precipitation.

6. Mechanical stress: Long-term mechanical stress may also cause plasticizers to precipitate from PVC products.

7. Product design: Unreasonable product design, such as uneven thickness, may also lead to uneven distribution of plasticizers, which will then precipitate.

Solutions:

1. Choose the right plasticizer: Choose a plasticizer that is compatible with PVC to improve its stability in PVC.

2. Optimize the amount of plasticizer added: According to the type and performance requirements of PVC resin, accurately calculate the amount of plasticizer added to avoid excessive amounts.

3. Use stabilizers: Add an appropriate amount of stabilizers, such as antioxidants, UV inhibitors, etc., to enhance the heat resistance and light resistance of PVC products.

4. Improve processing technology: Control the processing temperature to avoid excessive processing temperature causing plasticizer volatilization.

5. Improve storage conditions: Avoid long-term exposure of PVC products to high temperature, high humidity and ultraviolet radiation.

6. Improve product design: Ensure uniform product thickness and avoid excessive local plasticizer concentration.

7. Surface treatment: Coating the surface of PVC products to reduce the migration and precipitation of plasticizers.

8. Use compatibilizers: Add compatibilizers to improve the compatibility of plasticizers with PVC resins and reduce precipitation.

Through the above measures, the precipitation of PVC plasticizers can be effectively reduced and the stability and service life of PVC products can be improved.