Polypropylene (PP) is a popular thermoplastic polymer. It is vital in packaging, appliances, and auto parts. Its easy processing and great properties make it useful. PP still has some limits. It has high heat shrinkage, low performance in cold, and poor impact resistance. These problems have led people to add inorganic mineral powders to it. They hope to improve its performance and broaden its uses.
Calcium carbonate
Calcium carbonate is a common filler for synthetic resins, especially polypropylene (PP). Its abundant, non-toxic, and easy-to-handle varieties make it ideal for this use. Calcium carbonate has three main types: nano, heavy, and light. The different calcium carbonate powders have unique effects in polypropylene modified filling materials. This is due to their specific physical and chemical properties.
talcum powder
Talc is a natural mineral rich in magnesium silicate. It has a unique layered structure, good insulation, and stability. So, it is widely used in polypropylene (PP). It can greatly reduce the shrinkage of PP materials. It can also raise the tensile modulus to some extent. This improves its mechanical properties and stability.
Mica powder
Mica’s unique properties make it vital in insulation, plastics, rubber, paper, and paints. Mica has a special large-diameter ratio structure. It reinforces plastic products. It can improve the properties of plastic products. These include mechanical and vehicle parts, plastic wood products, appliance housings, packaging, films, silks, and ropes.
Silicon dioxide
Silica powder is a widely used inorganic material. It is favored for its high purity, regular shape, and various preparation methods. Nano-silica can improve composite materials in polymers. Its unique 3D structure and large surface area make it effective.
Kaolin
Kaolin is a powder made of kaolinite clay minerals. It forms from the weathering of feldspar and common pyroxene. They are aluminosilicate minerals. This powder is usually a fine, matte, white. It has plasticity, adhesion, and volume expansion when pure. Kaolin can improve the tensile strength and modulus of thermoplastics. It can also increase the rigidity and strength of plastic products. When added to polypropylene, it acts as a nucleating agent. Calcined kaolin can boost the electrical insulation of plastics. It can be used in wires, cables, and high-voltage insulation products. Kaolin blocks infrared light well. It has been used in military equipment. It can improve the thermal insulation effect when used in films.
Wollastonite
Wollastonite can be widely used in PET, PA, PE, PP, ABS and other resins. Many of its properties are similar to those of inorganic powders such as talc and mica. Wollastonite is a new inorganic modified material in plastics. Its processing tech must maintain a large aspect ratio rod structure. It should also use a silane coupling agent for surface activation. This will improve or ensure the compatibility of different materials. Wollastonite can raise the heat deformation temperature of the resin. It can fix the issues of a water-absorbing resin in humid environments. Water absorption lowers its strength and modulus. Different resins also improve its physical properties.
Barium sulfate
Barium sulfate (BaSO4) has two types. One is natural barium sulfate, or barite powder. The other is artificially synthesized barium sulfate. The specific surface area of synthetic barium sulfate is 22000~140000cm2/g. As a plastic filler, it can make the surface of the product smooth and have good gloss. Barium sulfate also has excellent properties. It is stable, scratch-resistant, heat-resistant, and has a high refractive index. It also disperses easily. It outperforms many inorganic powders in sound insulation, heat retention, and gloss. It is widely used in home appliance housings, masterbatches, films, pipes, and profiles. But, the specific gravity of barium sulfate affects its application.
There are many types of inorganic powders. Their use in PP modification is well-established. For rich downstream apps, PP’s performance requirements will differ. High-performance inorganic powders offer more options. They enable precise filling modification.