Solvay Exhibits High-Performance Polymers for
Membranes for the Water Industry at Aquatech China 2014

Largest Choice of Sulfone Polymers and Fluoropolymers
for Hollow Fibre, Flat Sheet and Tubular Membranes

Specialised Membranes Lab in Shanghai to Meet Local Market Needs

SHANGHAI, PR China, June 25, 2014 – At the largest water show for the Greater Chinese and Southeast Asian markets, Solvay Specialty Polymers is addressing the membranes industry with an extensive materials portfolio and expertise designed to give customers the right solution for any membrane technology. Solvay has also established a specialised Membrane Laboratory in Shanghai to underscore its strong commitment to the Chinese market and make sure that local customers will receive the fast response and support they need in this growing industry segment. Solvay made the announcement today at Aquatech China 2014 in Shanghai.

“As environmental protection has greatly gained in both importance and momentum in China, manufacturers of water processing and water treatment systems are  facing enormous challenges to ensure the performance and quality required in the wide field of the water sector”, says Dr. Luke Du, General Manager of Greater China & Southeast Asia for Solvay Specialty Polymers. “We offer customers the largest choice of sulfone polymers and fluoropolymers with the right solubility, purity and molecular weight for hollow fibre, flat sheet and tubular membranes providing exactly the required pore size and separation selectivity.”

Technologies served by these polymers range from symmetric as well as asymmetric membranes for reverse osmosis (RO), microfiltration (MF) and ultrafiltration (UF) processes. High molecular weight grades enhance fibre strength and minimise fibre breakage. Key characteristics include low levels of insolubles and extractibles, high stability at acidicylevels down to pH 1 and alkaline levels up to pH 14, and global agency approvals. Typical water applications range from support layers for RO membranes to membranes for RO pre-treatment, from membrane bio-reactors for industrial and municipal wastewater treatment to drinking water filtration membranes. Further proven application areas include membranes for haemodialytic blood purification, filters for bio-pharmaceutical separation processes, MF and UF membranes in concentration and clarification processes for food and beverage products, and various gas separation processes.

Solvay’s sulfone polymers – notably Udel^®polysufone (PSU), Veradel^®polyether sulfone (PESU) and Radel^®polyphenylsulfone (PPSU) – have successfully been in membrane production for over 25 years. Soluble in conventional processing solvents, they combine excellent mechanical properties and hydrolytic stability with outstanding biocompatibility. End products can be sterilised in steam, ethylene oxide (ETO) or by gamma irradiation, which makes these high-performance polymers suitable for potable water and FDA compliant food contact applications. Low cyclic dimer grades improve the stability of dopesolutions, reduce filter clogging, and minimise manufacturing defects. Udel^® PSU has long been the industry standard for manufacturing the support layers used in the production of RO and nanofiltrationthin-film composite membranes. The Udel^®P‑3500 LCD MB series of polymers, in particular, is widely used around the world for making high-pressure water filtration membranes.

For hollow fibre and flat sheet membranes that must provide high chlorine and UV resistance along with excellent toughness and durability, Solvay offers Solef^®polyvinylidene fluoride (PVDF) homopolymers produced in a suspension polymerisation process that results in a linear, gel-free product. These materials have an ideal fit in diffusion or thermally induced phase separation (DIPS/TIPS) manufacturing processes using conventional solvents.

Halar^® ethylene chlorotrifluoroethylene (ECTFE) is a semi-crystalline, melt-processable fluoropolymerthat provides exceptional chemical resistance for hollow fibre membranes manufactured in a TIPS process close to the polymer’s melting point. Typical solvents used to process this material are acetyltributyl citrate, glycerol triacetate (GTA), dibutyl phthalate (DBP) and dioctyl phthalate (DOP).The resulting membranes feature outstanding ozone, chlorine and caustic resistance together with high tensile strength. Selected material grades are also available in FDA compliant versions.

The TIPS technology has emerged as a particularly attractive manufacturing method for defect-free porous membranes with excellent mechanical performance. Both Solef® PVDF and Halar® ECTFE are the materials of choice in these thermal processes due to their solubility in a range of solvents at high temperatures. DIPS or non-solvent induced phase separation, in contrast, is highly sensitive to spinning and dope solution variables, which requires very tight process control during membrane casting and dopepreparation. This can only be accomplished by using “best in class” polymers with optimum lot-to-lot consistency.

All materials are manufactured at Solvay’s production plants worldwide to the same standards of quality and consistency. In addition, the company maintains and regularly updates the status of its membrane materials with global regulatory agencies and specifications. To better serve customers in the growing Chinese membrane industry, the Membrane Lab at Solvay’s Shanghai R&I Center offers specialized support and assistance from material testing to membrane design and process optimisation.

For more detailed information about Solvay’s comprehensive portfolio of high-performance membrane polymers, the company’s specialists are available during Aquatech China 2014 at Shanghai’s World Expo Exhibition and Convention Center from June 25 to 27, Booth 2.040.

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