How to improve the anti-scratch of PP compounding?

Polypropylene PP

Polypropylene, abbreviated as PP, is a polymer formed by the addition reaction of propylene. It is a white waxy material with a transparent and lightweight appearance. The chemical formula is (C3H6) n, with a density of 0.89-0.91g/cm3. It is flammable and has a melting point of 164-170 ℃. It softens at around 155 ℃ and can be used in the temperature range of -30-140 ℃. It can withstand corrosion from acid, alkali, salt solution, and various organic solvents below 80 ℃, and can decompose under high temperature and oxidation. Polypropylene is a high-performance thermoplastic synthetic resin, which is a colorless and semi transparent thermoplastic lightweight universal plastic. It has chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties, and good high wear resistance processing performance. It is widely used in the production of fiber products such as clothing and blankets, medical equipment, automobiles, bicycles, parts, conveyor pipelines, chemical containers, and also in food and drug packaging.

 

Advantages of PP:

Odorless, tasteless, and non-toxic. It is the lightest type of commonly used resin;

Excellent mechanical properties, including tensile strength, compressive strength, and hardness, outstanding rigidity and bending fatigue resistance. The movable hinge made of PP can withstand 7 × Folding and bending more than 107 times without damage, resulting in poor impact strength at low temperatures. The tensile strength of PP is generally 21-39 megapascals; Bending strength 42-56 MPa, compressive strength 39-56 MPa, elongation at break 200%~400%, notch impact strength 2.2-5 kJ/m2, low-temperature notch impact strength 1-2 kJ/m2. Rockwell hardness R95~105;

Good heat resistance, continuous use temperature can reach 110-120 ℃;

Good chemical stability, except for strong oxidants, it does not interact with most chemical drugs; At room temperature, solvents cannot dissolve PP, only some halogenated compounds, aromatic hydrocarbons, and high boiling fatty hydrocarbons can make it swell, and its water resistance is particularly good;

Excellent electrical performance, good resistance to high-frequency electrical insulation, and good electrical insulation even in humid environments;

Due to the presence of many methyl tertiary carbon atoms on the main chain of PP, the hydrogen on the tertiary carbon atoms is easily attacked by oxygen, resulting in poor weather aging resistance of PP. Therefore, antioxidants or UV absorbers must be added.

 

Application:

Injection molded products account for 50% of the total consumption in European and American countries, mainly used as parts for automobiles and electrical appliances, various containers, furniture, packaging materials, and medical equipment; Film accounts for 8% to 15%, while polypropylene fiber (commonly known as polypropylene fiber in China) accounts for 8% to 10%; Pipes and sheets used in construction account for 10% to 15%, while others account for 10% to 12%. Currently, 40% to 45% of China’s products are used for weaving, followed by about 40% for film and injection products; Polypropylene and others account for 10% to 20%.

China mainly applies polypropylene as a material in fields such as food packaging, household items, automobiles, and optical fibers. The largest areas in which polypropylene is used in China are woven bags, packaging bags, tying ropes, and other products, accounting for approximately 30% of total consumption. In recent years, with the development of polypropylene injection molded products and packaging films, the proportion of polypropylene used for weaving products has decreased, but it is still the area with the highest consumption of polypropylene. Injection molded products are the second largest consumer area of polypropylene in China, accounting for about 26% of the total consumption, and it is also one of the regions with the largest demand for polypropylene in the future. Another major consumer area of domestically produced polypropylene is film, accounting for about 20% of the total consumption, mainly BOPP (biaxially oriented polypropylene film). In the coming years, the proportion of textile products will gradually decrease, while the proportion of injection molded products, pipes, and sheets will increase. According to experts’ predictions on the development of the polypropylene industry, the demand for polypropylene in China is likely to reach around 23.7 million tons by 2020. Textile products, injection molded products, and films are still the main demand areas for polypropylene in China, while the annual demand for pipes, plates, fibers, and other fields is growing rapidly, and the domestic demand for polypropylene is also growing rapidly. The market development prospects for special materials such as high-speed drawing BOPP films, pipes, thin non-woven fabrics, and highly transparent food containers are promising.

Mechanical and automotive manufacturing components

Polypropylene has excellent mechanical properties and can be directly manufactured or modified to manufacture various components of mechanical equipment, such as industrial pipelines, agricultural water pipes, motor fans, infrastructure templates, etc. Modified polypropylene can be molded into bumpers, anti friction strips, car steering wheels, instrument panels, and interior decorations, greatly reducing the weight of the vehicle body and achieving the goal of energy conservation.

 

Electronic and electrical industrial devices

Modified polypropylene can be used to make insulation shells and washing machine liners for household appliances, and is commonly used as insulation materials for wires, cables, and other electrical appliances. The polypropylene composite material made by mixing 60 to 80 parts by weight of homopolymer polypropylene, 20 to 40 parts by weight of ethylene vinyl alcohol copolymer, and 1 to 10 parts by weight of compatibilizer (reaction product of polypropylene maleic anhydride graft and ethylene vinyl alcohol copolymer) at 170 ℃ to 190 ℃ has high toughness, an impact strength of up to 210J/m, high gas barrier performance, and a water vapor permeability rate close to 2000g· μ M/(m2 · 24h). When preparing barrier films, traditional film making processes can be used for production, which are relatively simple and have lower production costs.

 

Construction

Polypropylene fiber is the lightest among all chemical fibers, with a density of (0.90~0.92) g/cm3. It has advantages such as high strength, good toughness, good chemical and microbial resistance, and low cost. Polypropylene reinforced with glass fiber or modified with rubber or SBS is widely used in the production of construction templates. Foamed polypropylene can be used to make decorative materials. When an earthquake occurs, the failure mode of polypropylene fiber reinforced ceramic aggregate concrete is plastic failure, with no debris peeling off. Choosing polypropylene fiber ceramic aggregate concrete is safer than using plain ceramic aggregate concrete.

 

Other industries

In the chemical industry, polypropylene can be applied to prepare various corrosion-resistant transportation pipelines, storage tanks, valves, irregular fillers in packing towers, filter fabrics, corrosion-resistant pumps, and lining of corrosion-resistant containers; In the field of medicine, it can be used to make medical devices; Polypropylene can also be developed and applied in the energy field through grafting, compounding, and blending processes.

Polypropylene Compounding

In response to the poor impact resistance, poor weather resistance, poor surface decoration of polypropylene at low temperatures, and the gap between its functionality in electrical, magnetic, optical, thermal, and combustion aspects and actual needs, modifying polypropylene has become the most active and fruitful field in the current development of plastic processing

Blending modification is a modification method that involves blending PP (polypropylene) with polyethylene, engineering plastics, thermoplastic elastomers, or rubber to enhance the performance of PP. Blending modification is completed in processing equipment such as internal mixers, open mixers, and extruders. The process is easy to control, the production cycle is short, and the cost is low. It can improve the coloring, processing, anti-static, impact resistance, and other properties of PP. Polymer blending can integrate the outstanding performance of each component, compensate for the shortcomings in the performance of each component, and significantly improve the overall performance of the blend. However, the low temperature resistance and aging resistance of PP modified by blending are still not ideal. During blending modification, shear force may cause some large molecular chains to be cut off to form free radicals and form graft or block copolymers, which can also effectively enhance the compatibility of PP.

Our Xiangxi silicon masterbatch DX8502 can be added in the process of PP compounding.

• DX8502 can improve the anti-scratch of PP compounding.
• DX8502 can improve the demoulding of PP compounding.
• DX8502 can improve the dispersibility of PP compounding.
• No tackiness,not odor,no exudation,low VOC and less influence of stress whitening.