PVC, PE, PP, and PS are general-purpose plastics. The characteristics of the particular plastic are determined by its chemical composition and type of molecular structure.
PVC has an amorphous structure with polar chlorine atoms in the molecular structure. Chlorine atoms and amorphous molecular structure are inseparably related. Although plastics appear very similar in the context of everyday use, PVC has completely different characteristics in terms of performance and functions compared to olefinic plastics that have only carbon and hydrogen atoms in their molecular structures.
Chemical stability is a common characteristic of halogen-containing substances such as chlorine and fluorine. This applies to PVC resins, which also possess fire retardant properties, durability, and oil / chemical resistance.
PVC has inherently superior fire retardant properties due to its chlorine content, even in the absence of fire retardants. For example, the ignition temperature of PVC is as high as 455 ° C, and it is a material with less risk of fire incidents, as it does not ignite easily.
Ignition temperature of PVC In addition, the heat released in combustion is considerably lower with PVC, compared to PE and PP. Therefore, PVC contributes much less to spreading fire to nearby materials even while burning.
Therefore, PVC is very suitable for safety reasons in products close to people's daily life.
Under normal conditions of use, the factor that most strongly influences the durability of a material is resistance to oxidation by atmospheric oxygen. PVC, which has the molecular structure where the chlorine atom is attached to every other carbon chain, is highly resistant to oxidative reactions and maintains its performance for a long time. Other general-purpose plastics with structures consisting of only carbon and hydrogen are more susceptible to deterioration by oxidation under conditions of long-term use (such as through repeated recycling). Measurements on 35-year-old PVC underground pipes taken by the Japan PVC Pipe and Fittings Association showed no deterioration and the same strength as new pipes.
