Random Copolymer PP Homopolymer PP Block Copolymer PP

Polypropylene is a polymer composed of monomers (chemical formula: CH2=CH-CH3) connected by covalent bonds. The  monomers on the molecular chain are connected by carbon-carbon single bonds to form a linear chain structure. According to the different spatial arrangements of the side chain methyl groups, it can be divided into three forms: isotactic, syndiotactic and random (Figure 2). Isotactic polypropylene has side methyl groups on the same side of the main chain plane [1] and has a regular structure, so it has high crystallinity, high melting point, high hardness and stiffness, and excellent mechanical properties. The side methyl groups of random polypropylene are completely disorderly distributed on both sides of the main chain [1]. It is an amorphous material with very low strength and little value when used alone. It cannot be used in plastics, but it works well as a carrier for filling masterbatch. , often used to modify carriers. The side methyl groups of syndiotactic polypropylene are regularly distributed alternately on both sides of the main chain [1]. Its performance is between the first two. It is a low-crystalline polymer produced with a metallocene catalyst. It is a highly elastic thermoplastic material with It is transparent, tough and flexible. Its stiffness and hardness are only half of isotactic polypropylene, but its impact properties are better. It can be vulcanized like rubber, and the mechanical properties of the resulting elastomer exceed those of ordinary rubber [22]. In the polypropylene resin generally produced, the content of isotactic structure is 95%, and the rest is atactic or syndiotactic . Industrial products contain isoforms as main components.