Yes, it is possible for some individuals to have a sensitivity or allergic reaction to titanium dioxide, although it is considered relatively uncommon. Reactions can include skin rashes or irritation, and in more severe cases, difficulty breathing. However, titanium dioxide is generally considered safe and is commonly used in a wide variety of products, from sunscreen to food and cosmetic products. But, like any substance, it's always possible for someone to develop a sensitivity to it. If you suspect you're having an allergic reaction to a product containing titanium dioxide, contact a healthcare professional.

Premature Ventricular Contractions (PVCs) are extra heartbeats originating from the ventricles. Common symptoms include palpitations or the feeling of the heart skipping a beat, fluttering, or pounding. Some individuals might experience dizziness, breathlessness, or even chest pain in more severe instances. However, not everyone feels these symptoms, and PVCs can sometimes go unnoticed unless detected through an ECG or similar heart monitoring. Factors like stress, caffeine, alcohol, and certain medications could trigger or exacerbate PVCs. While often benign, frequent PVCs or those experienced alongside heart disease could indicate a more significant health issue, necessitating a medical evaluation for appropriate management.

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.