Polypropylene is a thermoplastic resin polymerized from propylene. Polypropylene also includes a copolymer of propylene and a small amount of ethylene. Usually a translucent colorless solid, tasteless and nontoxic.

2065438+07101The list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference. Polypropylene is in the list of three types of carcinogens.

Polyethylene is a thermoplastic resin prepared by ethylene polymerization. In industry, it also includes * * * polymers of ethylene and a small amount of α-olefins. Polyethylene is odorless and nontoxic.

On October 27th, 2065438+071KLOC-0, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference. Polyethylene is in the list of three types of carcinogens.

Extended data

physicochemical property

Polyethylene and polypropylene are odorless and nontoxic low-density polymers. They have low water absorption, are particularly stable to water and have extremely low water absorption.

1, chemical properties

Both have excellent chemical stability.

Polyethylene is resistant to various chemicals at room temperature, but nitric acid and sulfuric acid have a strong destructive effect on polyethylene.

Besides being corroded by concentrated sulfuric acid and nitric acid, polypropylene can also be softened and swollen by low molecular weight aliphatic hydrocarbons, aromatic hydrocarbons and chlorinated hydrocarbons, and its chemical stability increases with the increase of crystallinity.

2. Electrical performance

Both of them have high dielectric constant and can be used to make electrical insulation products that heat up with the increase of temperature. The breakdown voltage of polypropylene is also very high, and it is suitable for electrical accessories. , with good voltage resistance and arc resistance.

3. Thermal characteristics

Polyethylene has excellent low temperature resistance (the lowest service temperature can reach-100 ~-70℃). Cold resistance is better than polypropylene.

Polypropylene has good heat resistance, and will not deform at 150℃ without external force. The brittleness temperature is -35℃, and embrittlement will occur below -35℃. The melting temperature of polypropylene is about 40-50% higher than that of polyethylene.

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