Fluoropolymers

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

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

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

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

⁽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

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

⁽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.

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

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