- Suzhou Haolilai Engineering Plastic Co., Ltd.
- Mobile: 86 0512 62697848
- Phone: 86 0512 62697848
- Address: South District, Guangfu Town Industrial Zone, Wuzhong District, Suzhou, Jiangsu, China
How about compatibility in flame retardant pp plastic?
Suzhou flame retardant pp plastic is favored by more and more manufacturers due to its light density, excellent weather resistance and low comprehensive price. It has successfully replaced flame retardant PS and flame retardant ABS in many applications. How about compatibility in flame retardant pp plastic?
Behind the rise of flame retardant PP materials, one problem that may be often encountered is the precipitation of flame retardant pp materials, which is more obvious in halogen-free flame retardant PP materials.
The precipitation of flame retardants often not only causes powdery agglomeration, mold scum and other mold scales during the injection molding process to affect normal production, but also often occurs in the finished product, which produces white mist-like substances, affecting the appearance of the product and reducing the flame retardancy And other issues.
PP is a semi-crystalline substance and has a low glass transition temperature. When the ambient temperature is higher than its glass transition temperature, as the temperature increases, the thermal movement of the amorphous segment will accelerate, making it in phase with the PP resin. Small-capacity small-molecular flame retardants can easily overcome the resistance to migrate to the surface.
This is also the reason for the appearance of precipitation on the surface after the product has been stored for a period of time. The high-temperature injection molding process is the most obvious precipitation process, and its precipitation is often reflected in the mold. The higher the injection temperature, the more precipitation.
Flame retardants are generally in two states in PP resins: one is filled into the resin as a filler, and the other is evenly dispersed in the resin in a melted state. Because PP is a non-polar material, there is an interface compatibility issue between polar flame retardants and PP. The worse the interface compatibility, the more likely it is to cause precipitation problems.
The introduction of strong polar groups can enhance the interface between flame retardant and PP, which can effectively reduce the problem of flame retardant precipitation. Improve the migration resistance between flame retardants and resins, and reduce the migration rate of low molecular weight flame retardants: reduce the temperature to reduce the movement between segments or increase the degree of polymerization of flame retardant molecules, and reduce the width of molecular weight distribution to reduce the flame retardant Effective measures for precipitation.