In today's environment where the plastics market is expanding day by day, the world's plastics industry is in a state of development. The global growth rate of plastics has reached 4% to 6%, and has now exceeded the global GDP growth level. At present, in our lives, plastics have replaced metal, wood, minerals, etc. in many fields. The use of plastic products continues to increase, which makes the PVC industry continue to expand. Technology is the key to ensuring product quality. When we produce and process PVC products, we will use a variety of PVC processing aid products, PVC processing There are many types of additives: plasticizers, heat stabilizers, pigments, catalysts and so on. Different PVC processing aids have different effects on PVC. In the process of using various PVC processing aids, polymer impact modifiers and processing aids provide polymers with the most unique and valuable outstanding performance, while also improving the processing performance of the product. Toughening treatment, rheological property control, aesthetic appearance, processing performance and economic factors are all important properties. All kinds of PVC processing aids have been used for many years, and a wide range of varieties have been derived after long-term development. Due to the variety in the emulsion polymerization of PVC processing aids, scientists continue to design suitable polymer components, polymer structure, polymer morphology, and polymer molecular weight and molecular weight distribution.
"Because the production cost of PVC processing aids is low, and the resulting emulsion products are easy to separate, emulsion polymerization is very attractive in commercial production. In 1956, the first PVC processing aid used in emulsion polymerization technology was developed. It was a core-shell structure impact modifier prepared from methacrylate-butadiene-styrene (MBS). Then came various acrylic processing aids and acrylic impact modifiers. Initially, these additives were mainly used to improve the processing properties and toughness of polyvinyl chloride (PVC). The main purpose of PVC processing aids is to promote the melting of PVC, improve melt strength, improve dispersion performance and surface quality. Ultra-high molecular weight processing aids are an important part of foamed PVC. With the help of processing aids, PVC foam can obtain a more uniform foam structure, reduce the rupture of closed bubbles, and the foam density will be lower. The lubricating processing aid can effectively prevent the molten plastic from sticking to the metal surface, improve the surface quality of the product, and increase the production efficiency.
There are many plastic materials whose application range is very limited. This is because they either do not have the required physical properties or have very poor processing properties. PVC processing aids are used to enhance the melt processability of plastics, increase production, and reduce Stop overhaul time and provide better quality of products. In the 1950s, Rohm and Haas took the lead in developing the first commercially produced processing aid product, which was used in the production of rigid PVC. After that, this unprecedented technology was quickly known by the industry, and thus triggered a production boom in the PVC industry. Since the 1980s, such research and development work began to be carried out for other thermoplastic materials and polymer blend products. Most of the processing aids are usually added in PVC, while the processing aids used in other thermoplastics are very few (only 0.5% to 5%), but nonetheless, these processing aids can significantly Improve processing performance, while not having too much impact on other application performance. According to different functions, processing aids can be divided into fluxes, melt rheology modifiers, lubricants and dispersion accelerators. In fact, each type of processing aid has more than one effect. The functionality and application effect of any processing aid depends on its chemical composition, polymer structure, polymer molecular weight, and polymer matrix type.