Q:Why the PTFE melting point is very high ?
A:PTFE molecular structure is a spiral columnar ! Peripheral atom is f ! Therefore intermolecular forces large ! And the presence of peripheral f atoms blocked c-f key ! Very resistant ! Plus a fluorine atom radius, regular arrangement , it is a non -polar crystalline polymers, the intermolecular forces is large, it is difficult to find its solubility parameter similar solvent at room temperature is difficult to dissolve . Can not dissolve in water , this material has acid alkali resistance characteristics of various organic solvents , almost insoluble in all solvents . Meanwhile, PTFE high temperature characteristics, its low coefficient of friction , it can be used for lubrication of the remainder , it has become an ideal coating for easy cleaning and pan pipe inner layer. There are two reasons , one of its δ = 6.2 (cal / cm3) 1/2, δ is difficult to find such a small solvent ; the second is its melting point up to 327 ℃, above the melting point system has a high viscosity, for amorphous crystalline polymer requires warmed to near the melting point , there is no suitable solvent could both have similar δ has a high boiling point .
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