Pvpp Polyvinylpolypyrrolidone25249-54-1

Polyvinylpolypyrrolidone cross-linked

CAS: 25249-54-1

Chemical formula: C6H9NO

Preparation method:

The cross-linking process of polyethylene can be basically divided into two categories: physical method and chemical method.

Physical cross-linking Cross-linking of polyethylene first began in the United States in 1955, using the radiation cross-linking method. The physical method is characterized by the use of external radiation sources, typically electromagnetic radiation.

(1) a radiation comes from radioactive isotopes or high-energy electron beams.

(2) B radiation comes from accelerators, using accelerated electrons or electromagnetic waves.

(3) Y radiation comes from Co isotopes. Y radiation is often used in laboratory research, and is generally only used for thin films and thin bottles in actual production. The electromagnetic beam (_B ray) generated by a large accelerator is usually used in production. It takes (0.88~1-6)×10-13J of energy to penetrate 1~3mm thick polyethylene. The main advantage of radiation cross-linking is that it is a post-cross-linking technology, which is easy to realize production automation and high-speed extrusion. Its disadvantages are that the cross-linking depth is limited, and for round objects, it must be rotated or several radiation sources must be used simultaneously; the equipment investment is large. In actual production, radiation cross-linking is usually used for wire coating, film and foaming materials, and is rarely used in pipe production.

Hot Tags: pvpp polyvinylpolypyrrolidone25249-54-1, China pvpp polyvinylpolypyrrolidone25249-54-1 manufacturers, suppliers, factory, Crospovidone Xl, Crospovidone Usp 42, Crospovidone European Pharmacopoeia Monograph, , Povidone Usp 42, Povidone Iodine Heb