The properties of teflon PTFE
1, Heat-resistant --using normally up to 250 ℃
2, Cryophylactic --good mechanical toughness; Even though the temperature dropped to Montreal, also can maintain ℃ elongation of 5%.
3, Corrosion resistance --For most chemicals and solvent, show strong acid alkali inert, water and all kinds of organic solvent.
4, Resistance to climate -- the best aging life in plastic.
5, High lubrication --the lowest coefficient of friction in solid materials.
6, Non-adhesive - is non-adhesive on the surface tension of the least of any material in solid materials.
7, Harmless - having physical laziness, as artificial vascular and viscera, there have no adwerse reactions long-term implanted in our bodies.
Ptfe have bigger relative molecular mass, low for hundreds of thousands, high up to more than 10 million, generally in the degree of polymerization millions (104 orders of magnitude, and polyethylene only in 103). For general crystallinity 90 to 95 percent, melting temperature for 327 ~ 342 ℃. Ptfe molecules in the shape CF2 units arranged, according to zigzag than hydrogen fluorine atoms radius due, so CF2 slightly adjacent cannot completely according to unit trans crossover orientation, but to form a spiral, fluorine atoms distorted chain almost covered the whole polymer chain surface. This molecular structure explained ptfe various performance. Temperature below ℃, 19 June 13 / formed spiral; In 19 ℃ phase change, molecular slightly untie, forming 15/7 spiral.
Although in all the fluorine carbon compounds carbon-carbon and fluorine key fracture need separate 346.94 and absorbing energy 484.88 kJ/mol, but ptfe depolymerization generating 1mol polyflon 171.38 kJ only energy. So in high temperature pyrolysis, ptfe main depolymerization for four fluorine ethylene. Ptfe in 260 ℃, the 370 and 420 weight loss rate (%) per hour 1 x 10 respectively 4, 4 x 10-3 and 9 x 10-2. Visible, ptfe ℃ for long-term use in 260. Due to high temperature pyrolysis when still produce toxic byproduct fluorine phosgene and all the fluorine isobutylene etc, so take special attention to safety and prevent ptfe contact open flame.