PCTFE  (Polychlorotrifluoroethylene)

PCTFE (Polychlorotrifluoroethylene)

PCTFE - has many properties similar to other fluoropolymers such as PTFE, FEP or PFA, but is mechanically superior in rigidity (does not deform easily), and has very low gas permeability . Its dimensional stability makes it attractive for use as a component of a structural part where the high temperature and chemical resistance of fluoropolymers is required. PCTFE shows high compressive strength and low deformation under load. However, its relative cost is one of the major considerations in its selection, since it is quite expensive.


Material Properties of Fluoropolymers – A Comparison

In general, the chemical resistance of fluoropolymers is superior to most other families of plastics. This “chemically inert” characteristic accounts for their superior performance in ultra-pure environments. The chemical inertness varies between the fluoropolymers. The fully fluorinated resins such as PTFE, FEP, PFA and MFA exhibit chemical inertness to a wider range of substances than do the partially fluorinated polymers such as CTFE (or PCTFE) and ECTFE. A superior property in one or two areas is accompanied by a diminished property in others (for example PTFE properties are better than PVDF in chemical resistance but it has lower mechanical properties at normal ambient temperatures. Fully fluorinated polymers (perfluoropolymers) such as PTFE, FEP and PFA offer better thermal (higher use temperature) and chemical resistance properties than their partially fluorinated counterparts like ECTFE or PCTFE. However, partially fluorinated resins posses better mechanical properties, such as higher tensile strength, toughness, abrasion and cut-through resistance at ambient temperatures.

The selection of a resin for a specific use is based on criteria for that application; for example permeability at the use temperature may be a critical requirement and may override other features such as chemical resistance and tensile strength. In each case the choice of material is made by comparing the key property requirements and, of course, cost.


Typical applications of PCTFE

Moisture barrier in pharmaceutical blister packaging, water vapour barrier for protecting phosphor coatings in electroluminescent lamps, protection in liquid crystal display (LCD) panels which are sensitive to moisture. Protection for sensitive electronic components. Insulation for wires and cables.

Properties

Property Value Units Method
Tensile Strength 4860 - 5710
34 - 39
psi
MPa
D 638
Elongation 100 - 250 % D 638
Flexural Strength, 73°F 9570 - 10300
66 - 71
psi
MPa
 
Flex Modulus 200 – 243 x 103
1.4 – 1.7
psi
MPa
 
Impact Strength, Izod, 23 deg C 2.5 – 3.5 ft-lb/in D 256
Compressive Stress at 1% deformation 1570 – 1860
11 - 13
psi
MPa
D 695
Density 2.10 to 2.17 gm/cu.cm  
Property Value Units Method
Coefficient of Linear Expansion 7 x 10-5 K-1  
Melting Point 410 - 414
210 - 212
deg F
deg C
 
Thermal Conductivity 1.45
0.84
Btu/hr-.ft-deg F
watt/meter-K

ASTM C177

Specific Heat 0.22
0.92
Btu/lb/deg F
kJ/Kg/deg K
 

Heat Distortion Temperature,

66 lb/sq.in (0.455 MPa)

259
126
deg F
deg C
D 648
Processing Temperature 620
327
deg F
deg C
 
Property Value Units Method
Dielectric Strength, short time, 0.004” 3000 Volt/mil D 149
Arc-Resistance 360 sec D 495
Volume Resistivity, @ 50% RH 2 x 1017 ohm-cm D 257
Surface Resistivity, @ 100% RH 1 x 1015 Ohm sq-1 D 257
Dielectric Constant, 1 kHz 2.6 ε D150-81
Dissipation Factor, @ 1 kHz 0.02   D150-81
Property Value Units Method
Water Absorption 0.00 % increase in weight D570-81
Flame Rating+ Non-flammable   D 635
Coefficient of friction     D 1894
Specific Gravity 2.10 to 2.17   D 792
Moisture Permeability Constant 0.2 g/m, 24 hours  
O2 Permeability 1.5 x 10-10 Cc, cm/sq.cm, sec, atm  
N2 Permeability 0.18 x 10-10 Cc, cm/sq.cm, sec, atm  
CO2 Permeability 2.9 x 10-10 Cc, cm/sq.cm, sec, atm  
H2 Permeability 56.4 x 10-10 Cc, cm/sq.cm, sec, atm  
0.10985708236694