Fluoropolymers for Membranes

Proven Membrane Performance

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Solvay’s fluoropolymers are used to make microfiltration and ultrafiltration flat sheet and hollow fiber membranes for a wide range of bioprocessing and medical filtration applications.

Molecular weights with controlled viscosities along with very high purity levels make these materials an excellent choice for membranes covering a broad range of porosity and shapes.

 

Fluoropolymers for membranes
 PelletPowder
Solef® PVDF60106010
1015
6020
Halar® ECTFE901
902
 
Algoflon® PTFE Algoflon® DF
 MembraneDispersion
Aquivion® PFSAE79
E87
D83

Fluoropolymer Solutions

Excellent chemical resistance combined with hydrolytic stability, high strength and the ability to operate over a broad pH range makes these polymers the right choice for membranes used in demanding end-use environments.

Solef® PVDF

Solef® PVDF homopolymers are used to make durable, long-lasting membranes. Their toughness, chemical resistance and oxidative stability allow membranes to tolerate a wide variety of feed streams and cleaning methods. These materials are soluble in conventional processing solvents to make hollow fiber and flat sheet membranes by DIPS and TIPS processes.

Solef® PVDF homopolymers are made using a suspension-type polymerization process which provides a linear, gel-free product. They are available in powders and pellets that cover a wide range of molecular weights. High molecular weight grades improve fiber strength and minimize fiber breakage.

Typical Applications

  • Low pressure water filtration
  • Wastewater treatment
  • RO/NF pre-treatment

Key Features

  • High purity
  • Broad chemical resistance
  • Excellent mechanical properties
  • Continuous use up to 150°C
  • Excellent resistance to aging
  • Easy processing by solution
  • Broad molecular weight and high branching
  • Physiologically harmless and approved for contact with food products

 

SOLEF® PVDF GRADES FOR MEMBRANES
PelletPowderTypical Mol Wt, Mw (g/mol)*
Solef® 6010Solef® 6010300-320
 Solef® 1015570-600
 Solef® 6020670-700

*Data from GPC in DMAc with calibration in polystyrene
**10% solids solution in NMP, 25°C


Solvents for Solef® PVDF
Good SolventsGood Swelling AgentsPoor Swelling AgentsNon-Solvents
DMF
DMAc
NMP
TEP
DMSO
Acetone
Cyclohexanone
g-Butyrolactone
Tetrahydrofuran
Methyl-Ethyl Ketone
Water
Methanol
Ethanol
Toluene
n-Hexane

Abbreviations
DMAc: N,N-Dimethylacetamide
DMF: N,N-Dimethyl Formamide
DMSO: Dimethyl Sulfoxide
NMP: N-Methyl-2-Pyrrolidone
TEP: Triethyl Phosphate

Halar® ECTFE

Halar® ECTFE is based on ethylene and chlorotrifluoroethylene. It offers outstanding chemical resistance over a broad temperature range and is stable at pH levels from 1 to 14.

Because of its exceptional chemical resistance, the material cannot be processed using solution phase inversion. Instead, it must be processed at temperatures close to its melting point (200 –240°C) using a TIPS process for hollow fibers. Two grades having different molecular weights and melt temperatures are available.

Key Features

  • Outstanding resistance to ozone and chlorine
  • Stable at pH levels from 1 to 14
  • Limited solubility in organic solvents
  • Very good tensile properties
  • Processable by TIPS technology
  • FDA compliance for selected grades

Halar® ECTFE Grades for Membranes
PelletMelt Flow Index, g/10 min
ASTM D 1238, 275°C
Halar® 9011.0 (tested at 2.16 kg)
Halar® 9021.0 (tested at 5.0 kg)

Physical Properties

Physical Properties
PropertyTest MethodUnitsSolef®
6010
Solef®
1015
Solef®
6020
Halar®
901
Halar®
902
Form  pellet,
powder
powderpowderpelletspellets
DensityASTM D 792g/cm31.781.781.781.681.71
Molecular Weight, MwGPC vs PS
standards
g/mol
x 103
320570700  
Polydispersity  2.12.42.2  
Solution ViscosityBrookfieldcp330(1)1,400(1)2,700(1)  
Melt Flow IndexASTM Dg/10 min6.0(2)0.2(2)1.3(3)1.0(4)1.0(5)
Water Absorption
24 hours, 23°C
ASTM D 570%< 0.04< 0.04< 0.04< 0.1< 0.1

(1)10% NMP, 23°C, 50 rpm
(2)Melt flow condition 230°C, 5.0 kg (ASTM D 638)
(3)Melt flow condition 230°C, 2.16 kg (ASTM D 638)
(4)Melt flow condition 275°C, 2.16 kg
(5)Melt flow condition 275°C, 5.0 kg

Mechanical Properties

Mechanical Properties
PropertyTest MethodUnitsSolef®  
6010
Solef®
1015
Solef®
6020
Halar®
901
Halar®  
902
Tensile Strength
at Yield
ASTM D 638
23°C, 50
mm/min
psi
MPa
7,685-8,265
53-57
7,685-8,265
53-57
7,685-8,265
53-57
4,300
30
4,300-4,600
30-32
Tensile Strength
at Break
ASTM D 638
23°C, 50
mm/min
psi
MPa
5,075-7,250
35-50
5,075-7,250
35-50
7,685-8,265
25-50
7,800
54
6,500-7,400
45-51
Tensile
Elongation
at Yield
ASTM D 638
23°C, 50
mm/min
%5-105-105-1054-5
Tensile
Elongation
at Break
ASTM D 638
23°C, 50
mm/min
%20-5020-5015-50250250-300
Tensile
Modulus
ASTM D 638
23°C, 1
mm/min
kpsi
MPa
348
2,400
319
2,200
239
1,650
240(1)
1,655(1)
265(1)
1,827(1)
Flexion
Maximum
Load
ASTM D 790
23°C, 2
mm/min
psi
MPa
11,165
77
10,150
70
9,570
66
  
Flexural StrengthASTM D 638
23°C, 2.5
mm/min
psi
MPa
   6,800
47
7,840
54
Flexural
Modulus
ASTM D 790
23°C, 2
mm/min
kpsi
MPa
304
2,100
290
2,000
261
1,800
245
1,690
252(2)
1,737(2)

(1)Measured at 50 mm/min
(2)Measured at 2.5 mm/min

Thermal Properties

Thermal Properties
PropertyTest MethodUnitsSolef®
6010
Solef®
1015
Solef®
6020
Halar®
901
Halar®
902
Melting PointASTM D 3418°C173173171242220-230
Heat of Fusion
80°C to end of melt
ASTM D 3418J/g6160604228
Glass Transition
Temperature
DMTA°C-32-30-348585
Thermal StabilityTGA
1% weight loss, N2
°C375-400375-400375-400405405

Chemical Resistance & Solution Properties

Chemical Resistance & Solution Properties
PropertySolef®
1015
Solef®
6010
Solef®
6020
Hydrolytic Stability+++
Inorganic Acids+++
Organic Acids000
Alkali
Aliphatic Hydrocarbons+++
Aromatic Hydrocarbons+++
Aliphatic Alcohols000
Chlorinated Solvents+++
Dipolar Aprotic Solvents000
Chlorine(1)+++
Ozone+++
Sterilization by Gamma Ra(2)+++
Sterilization by Steam+++

(1)In absence of UV light
(2)Maximum 40 MRad

KEY

"+": Polymer is resistant. Any increase in weight is less than 2% and any decrease in weight is less than 0.3%. The tensile yield strength is at least 85% of the initial value.
"0": Use of polymer is limited. Response does not meet above criteria. For example, weight increase may be more than 2%. However, the polymer can be used if stress is low.
"–": Polymer is not resistant. There is considerable alteration of the polymer, such as dissolution or chemical or physical degradation.

COMMENTS

1. In general Solef is very resistant to inorganic acids. In carboxylic acids, the acidity does not affect polymer performance, although swelling may occur.
2. Dipolar aprotic solvents is a huge class of chemicals: some are solvents for PVDF (e.g. NMP) while some can be recommended for use in contact with PVDF at low temperatures (e.g. butyl acetate).
3. Chlorine and ozone are able to generate free radicals that can attack PVDF. In conditions promoting the formation of radicals (e.g. UV light), care must be taken for the use of the polymer as chemical attack was observed.
4. Gamma radiation could damage PVDF depending on the radiation dose. Good resistance was observed up to 20-40 MRad, but chemical attack may occur at higher doses.

Agency Approvals

Agency Approvals
 Solef® PVDFHalar® ECTFE
Bioprocessing
USP Class VI1008/0001901
902
Water Contact
NSF 611008/0001
1010/0001
1010/0901
6008/0001
6010/0001
6010/0000
901
902
 
Food Contact
FDA1000 and 6000 series comply with 21 CFR 177.2510  
EC Directive1000 and 6000 series comply with 2002/72/EC as subsequently amended  
NSF 511008/0001
1010/0001
1015/1001
6008/0001
6010/1001
6020/1001
  

For further specifications and details regarding these agency approvals, please contact your local sales representative.

Algoflon® PTFE

Algoflon® PTFE (polytetrafluoroethylene) is an inert, non-toxic polymer with unique performance and processing attributes. It is available in fine coagulated white powders produced by dispersion polymerization, then processed by paste extrusion into a fibrous matrix with structural integrity.

Algoflon® DF powders are easily expanded after extrusion of the polymeric matrix without the use of soluble fillers, foaming agents or chemical additives. This process generates the physical creation of a huge number of small pores in the structure of an object made of PTFE, providing an exciting new level of performance properties.

Key Features

  • Outstanding chemical inertness
  • Exceptional heat resistance
  • Stable at pH levels from 1 to 14
  • Optimum dielectric and insulating properties
  • Extremely low coefficient of friction
  • Self-lubricating
  • Self-extinguishing
  • Outstanding anti-stick and release properties
  • Excellent weathering and aging characteristics

Typical Applications

  • Food and beverage processing
  • Gas and liquid microfiltration
  • Water treatment
  • Industrial filtration (e.g., filter bags, dust collectors)
  • Chemically inert fuel-cell membranes and separators
  • Garments made from lightweight, waterproof, breathable fabrics

Key Benefits

  • Suitable for high-temperature applications
  • Highly durable for long service life
  • Reduced fouling and clogging of equipment
  • Optimum resistance to aggressive cleaning programs

Typical Properties of Algoflon® DF Powders
PropertyTest MethodUnits
Service Temperature -260 to 260°C
Heat Resistance Stable up to 260°C
0.001% weight loss per hour at 350°C
Chemical ResistanceASTM D 543High inertness
Solvent ResistanceASTM D 543Insoluble up to 300°C
Water AbsorptionASTM D 5700.0%
Friction CoefficientASTM D 1894Static = 0.08 Dynamic = 0.06
Thermal ConductivityASTM C 1770.24 W/m°C
FlammabilityUL 94V-0
Limiting Oxygen IndexASTM D 2683>95%
Aging and Weatherability Stable over 20 years of exposure

Aquivion® PFSA

Aquivion® PFSA (perfluoro sulfonic acid polymer) is a functionalized perfluoro-ionomer produced from vinyl fluoride monomer and sulfonyl fluoride vinyl ether. The polymer’s short, low molecular weight side chains make it unique among ionically conductive perfluoropolymers and impart unique performance advantages.

Typical Membrane Applications

  • Polymer electrolyte fuel cells (PEFC)
  • Electrolyzers
  • Gas humidification and pervaporation systems
  • Metal-ion recovery cells (Donnan dialysis)

Typical Dispersion Applications

  • Surface modifier for membrane filtration devices
  • Super acid catalyst systems
  • Electrochemical sensors
  • Cationic exchange resins
  • Electro-active polymers
  • Drug release devices

Key Features

  • Higher crystallinity for improved mechanical properties
  • Enhanced proton (and also Li+, Na+, K+) conductivity
  • Best-in-class ion conductivity, especially at high temperatures and low humidity
  • Very high functionality combined with excellent thermo-chemical resistance
  • Lower equivalent weight than competitive polymers
  • Shorter side chains than other ionically conductive perfluoropolymers
  • Unique combination of powerful functionality and excellent thermo-chemical resistance

Aquivion® PFSA Membranes and Dispersions
 Equivalent
Weight,
g/mol SO3H
Typical
Thickness,
microns
Typical
Concentration,
% ionomer
Typical Solvents
Membrane
Aquivion® E7979025-200  
Aquivion® E8787025-200  
Dispersion
Aquivion® D83830 6-20Water
1-Proponal
2-Proponal