PVC is a good friend of Hongyi Chemical.

PVC was once the world's largest-volume general-purpose plastic and is widely used in building materials, industrial products, and daily necessities.

Polyvinyl chloride (PVC) is a polymer formed by the polymerization of vinyl chloride monomer (VCM) in the presence of initiators such as peroxides and azo compounds or under the action of light and heat according to the free radical polymerization mechanism. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively called polyvinyl chloride resins.
PVC is an amorphous white powder with a small degree of branching. It begins to decompose at around 90°C and has poor stability to light and heat. It will decompose to produce hydrogen chloride at temperatures above 130°C or after long-term exposure to sunlight, and further autocatalytically decompose, causing discoloration and a rapid decline in physical and mechanical properties. At this time, PVC heat stabilizers need to be added to inhibit the decomposition of hydrogen chloride, and various lubricants need to be added to improve the fluidity and demolding properties of the solution.

Why should fluorescent brighteners be added to PVC?

1. Catalytic decomposition causes PVC plastics to turn yellow. The appearance colors of PVC plastics after adding various stabilizing and lubricating agents are also different, and the whiteness values ​​are not high. 2. To reduce costs, PVC processing needs to add a lot of calcium powder as filler. The color of calcium powder varies, and too much will reduce the weather resistance of PVC products, so whitening agents should be added to remove yellowing and improve weather resistance. 3. To reduce costs, PVC processing needs to add a lot of recycled materials. The color of recycled materials varies, so whitening agents should be added to whiten and remove yellowing.