Copolymer: The polymerization between two or more monomers or monomers and polymers is called copolymerization, and the product obtained by copolymerization is a copolymer. Block copolymers, graft copolymers, random copolymers, regular copolymers, etc.

Homopolymer: A polymer formed by the polymerization of one monomer is called a homopolymer.

PP-H is homopolymer polypropylene (translucent), which is what we call Type I polypropylene. We can know that it is polymerized from a single polypropylene monomer and does not contain ethylene monomer in the molecular chain. The PP-H molecular chain has a high degree of regularity, so the material has high crystallinity, the highest stiffness, the highest chemical resistance and high temperature resistance, and the worst impact resistance.

PP-B is block copolymerized polypropylene (milky white), which is what we call Type II polypropylene. Its ethylene content is relatively high, generally 7-15%. In the molecular sequence, the probability that two ethylene monomers and three monomers are connected together is very high, indicating that ethylene monomers only exist in the block phase. The ethylene segments existing in the form of blocks greatly improve the impact strength of the material. However, because the isotacticity of the PP-H molecular chain cannot be reduced, the crystallinity, melting point and heat resistance of the material cannot be fundamentally improved. . PP-B pipe is a type of hot and cold water pipe. It is relatively cheap. Its heat resistance and pressure resistance are very different from PP-R.

The flammability rating of titanium dioxide is 0.

Using PVC pipe for a dryer vent is not recommended or compliant with most building codes due to its inability to withstand the high temperatures generated by dryers. PVC can release toxic fumes when heated and potentially poses fire risks. Aluminum or galvanized steel ducts are preferred for their heat resistance and safety. These materials can handle the exhaust heat and moisture without degrading, ensuring a safer operation of your dryer. Always consult local building codes and manufacturer recommendations to ensure compliance and safety in your specific situation.