Polyvinyl chloride (PVC) is a versatile polymer widely used in construction, healthcare, and packaging. Its molecular structure consists of a carbon backbone with alternating carbon atoms connected to hydrogen atoms and chlorine atoms. This linear configuration gives PVC its rigid and durable properties. The chlorine atoms in the molecular chain enhance its chemical resistance, making it ideal for various applications. Polymerization of vinyl chloride monomers results in this structure through a process called chain polymerization. The physical properties of PVC can be modified through the addition of plasticizers, stabilizers, and fillers, making it adaptable for different uses, from rigid piping to flexible films.

Yes, epoxy does bond to metal, and quite effectively. This is because epoxy resins are designed to have excellent adhesion properties, and when properly prepared, metal surfaces offer a strong substrate for the epoxy to bond to. The key to achieving a strong bond lies in surface preparation. The metal surface should be clean, dry, and roughened slightly to provide a better mechanical grip for the epoxy. This can be done through sanding, abrasive blasting, or chemical etching. Once applied, the epoxy cures, forming a hard, durable bond that is resistant to chemicals, heat, and mechanical stress. However, it's crucial to choose an epoxy that is compatible with the specific type of metal you're working with, as different metals may have different requirements for effective bonding.

Not all mixtures of liquids qualify as emulsions. Soluble mixtures, where components form a single phase like alcohol in water, aren't considered emulsions. Also, suspensions, where solid particles are dispersed in a liquid without dissolving and can settle out, diverge from the emulsion definition. Additionally, gels, which exhibit a jelly-like consistency due to their cross-linked polymeric structure, and foams, where gas bubbles are dispersed in a liquid or solid matrix, don't meet the criteria for emulsions. Emulsions specifically refer to mixtures where tiny droplets of one liquid are dispersed throughout another liquid, typically with the aid of an emulsifying agent to prevent separation. Common examples include mayonnaise and salad dressings, where oil is dispersed in water or vinegar. The distinction lies in the phase and dispersion characteristics of the components involved.