Teflon for the production of Teflon sections

Polytetrafluoroethylene, or PTFE for short, is a synthetic or synthetic fluoropolymer of tetrafluoroethylene that has many applications. It is better known as the Teflon brand owned by Chemours. [1] Chemours was a spin-off of the American chemical industry giant Dupont. [1] It is also known as the Syncolon brand, which is owned by Chemours. Synco Chemical Corporation. [2]

This material is sometimes called Virgin Teflon, and the difference is that no recycled materials are used in its construction, while in Teflon mechanically, a percentage of Teflon is sometimes recycled. [3] Virgin Teflon is produced by the Food and Drug Administration. And American medicine is approved and mostly used in the pharmaceutical and food industries. [3]

Contents

1 History
2 applications
3 physical properties of this material [4]
۴ زیان‌ها
4.1.PFOA
5 sources
History

This substance was accidentally discovered by Plunkett in 1938. While he was trying to make a CFC refrigerant, perfluoroethylene was polymerized in his laboratory pressure apparatus (in this chemical reaction the iron in the container wall acted as a catalyst). It was registered in 1941, and three years later it was renamed Teflon. [4]

applications

The most widely used Teflon, about 50%, is in the manufacture of computer and aerospace power cables. (For example, coaxial cables) and this is due to the extraordinary dielectric properties of Teflon, [5] especially in radio frequencies. [5]

Due to the very low coefficient of friction of Teflon, it is used in the manufacture of sliding bearings, gears, seals, gaskets and gaskets, liners and floss [6] and other applications that require low friction slip.

Teflon thin film is widely used in the production of carbon fiber composites and fiberglass composites, especially in the aerospace industry.

Advertising poster for a non-stick frying pan from the 1960s covered with a layer of PTFE or Teflon.

The use of Teflon in the manufacture of non-stick kitchen utensils is well known.

Due to the anti-corrosion properties of Teflon against some types of acids and even super acids, it is used in making some acid storage containers.

Physical properties of this material [4]
Characteristics of PTFE
Unit value attribute
Density g / cm³ 2. 2
Melting point 327 ° C
Young GPa modulus 0.5
Surrender resistance MPa 23
friction coefficient
0.05–0.10
Dielectric constant
ε = 2 ٫ 1, tan⁡ (δ) <5 (-4)
Dielectric constant (60 Hz)
ε = 2 ٫ 1, tan⁡ (δ) <2 (-4)
Dielectric resistance (1 MHz) MV / m 60
Losses

When PTFE molecules fail thermally, compounds such as sodium trifluoroacetate, chlorodifluoroacetate, and carboxylic acids are formed. Some recent studies have shown the adverse effects of these compounds on human health and the detrimental effects of the environment and are therefore being replaced in the US market. [7]

PFOA

Perfluorooctanoic acid (PFOA or C8) is used as a surfactant in the polymerization of PTFE emulsions, although some manufacturers have completely discontinued its use.

PFOA remains unsustainable in the environment indefinitely. [8] It is found in the blood of 98% of Americans in very small amounts in the fraction per billion range. Of course, this amount dropped to 70% for PFOA and 84% for PFOS from 1999 to 2014, coinciding with the ban on PFOA and PFOS in the United States. [9] [10] C8 are exposed to PFOA in the ocean near the Ohio River Valley. [11] [12] [13] PFOA in materials such as industrial waste, stainless carpet, carpet detergent, house dust, water, food and Teflon containers has been seen.

As a result of a standard litigation and social settlement with DuPont, three epidemiologists conducted a study on the population of a chemical plant that was more exposed to POFA than the general population in the United States. These studies concluded that there is a link between exposure to PFOA and six health outcomes: kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, hypercholesterolemia (high cholesterol), and gestational hypertension. [14]

Overall, Teflon containers are considered a minor source of PFOA exposure. [15]