Polysulfone PSU , Polyethersulfone PES

Total world consumption of PSU/PES was estimated at 22,700 tonnes in 2002 compared with peak demand of 22,900 tonnes in 2000. Between 1995 and 2000, the global PSU/PES demand increased at an annual rate of between 15-16%. In 2001, global PSU/PES demand declined by 5.3% due to the sharp downturn in key market sectors. 

There was a modest recovery in world demand during 2002, with estimated growth of 4.7%. For the period 2002-2007, world PSU/PES consumption is projected to increase at a very respectable compound annual growth rate of between 10-11%. Growth will however be lower than the historical trend rate due to the downturn in demand from key markets and maturing applications. 

North America is by far the largest consiuner of PSU/PES with 57.1% of total world consumption in 2002. Europe is second largest market with 19.4%, followed by Asia with the remaining 23. 4%. 

The E E sector is the largest user of PSU/PES with 28.6% of total world consumption in 2002. The second largest user is the automotive sector with 19.7% of world consumption, followed by consumer products with 14.7% and industrial with 12.8%. Other markets account for the remaining 23.3% of market volimies. The most important market included under the others  

In 2001, global LCP consumption declined by 9-10% due to a downturn in key applications such as cellular phones and personal computers. In Japan, LCP consumption fell by 15-20% due to a sharp contraction in US demand for IT products, a major market for Japanese producers. European and North American demand was down by 5-10% in 2001. There was a sharp recovery in global demand last year with an estimated growth rate of 8.6%. Asia showed the highest growth, but there were also strong performances from Europe and North America. 

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Table 3.1 shows continuous use temperatures for engineering and high performance polymers. For comparative purposes, 30% glass fibre-reinforced grades have been selected. PEEK has the highest continuous use temperature of up to 260 C, followed closely by liquid crystal polymers. Other high performance polymers are polyphthalamide (PPA), polyamideimide (PAI), polyarylimide, polyphenylene sulfone (PPSU), polyphenylene sulfide (PPS), polyetherimide (PEI), polysulfone (PSU), polyethersulfone (PES). 

The diphenylsulfone group is supplied to the repeat unit of all polysulfones by DCDPS. Differentiation among various polysulfones comes from the choice of bisphenol. Three different and commonly used bisphenols lead to three commercially important polysulfones referred to generically by the common names polysulfone (PSF), polyethersulfone (PES), and polyphenylsulfone (PPSF). Other common shorthand designations for polysulfone and polyphenylsulfone are PSU and PPSU, respectively. The repeat units of these polymers are shown in Table 1. 

A number of amorphous thermoplastics are presently employed as matrices in long fiber composites, including polyethersulfone (PES), polysulfone (PSU), and polyetherimide (PEI). AH offer superior resistance to impact loading and higher interlaminar fracture toughnesses than do most epoxies. However, the amorphous nature of such polymers results in a lower solvent resistance, clearly a limitation if composites based on such polymers are to be used in aggressive environments. 

UF membranes are usually prepared by phase inversion. The most widely used polymer for the preparation of UF membranes is polysulfone (PSU) or polyethersulfone (PES). 

The engineering polymers that have already reached maturity consist of the Nylons (PA), polycarbonate (PC), acetal (POM), polyesters (PBT and PET) and Noryl (PPO). Their relative price is aroxmd 3. Including very novel polymers, a prestigious high priced group consists of the advanced engineering polymers (high performance) polysulfone (PSU), polyphenylene-sulfide (PPS), fluoroethylenes (PTFE and its derivatives), polyamide-imide (PAI), polyether-imide (PEI), polyethersulfone (PES), polyether-ether-ketone (PEEK), aromatic polyesters and polyamides, polyarylates and liquid-crystal-polymers (LCP). 

Polysulfone (PSU) (typical structure shown in Figure 5.7) and polyethersulfone (PES) (typical structure shown in Figure 5.8) are highly versatile engineering polymers that have been applied in a variety of applications, including gas separation, membrane filtration, pervaporation, and electrodialysis. They have excellent chemical and mechanical stability, a relatively high glass transition temperature, and are easily cast as films from common aprotic solvents such as l-methyl-2-pyrrolidone (NMP) [32] and A lV-dimethylacetamide (DMAc) [33]. PSU has most commonly been evaluated for DMFCs as a blend with other... 

Group 1, Polysulfone-family Mmibers Polysulfone (PSu, Fresenius Medical Care, Germany), Polyethersulfone (PES, Membrana, Nipro Medical Corporation, J an), Polyester polymer alloy (PEPA, Nikkiso, Japan), Blends from Polyamide/Polysidfone (PA/PSu, Gambro, Sweden), as well as blends made of PES/PVP. Recent research on membranes with antioxidant features have led to the production of a polysulfone membrane with immobilized Vitamin E (PSuAfit E, ASAHI, Japan). 

Fig. 13.4 Chemical structure and characteristics of polysulfone (PSu) polymers used for dialysis membranes. Its specific chemical characteristics are shown in the panel above. PSu- membrane dimensions are depicted in the centered panel, a capillary cross section, inner diameter 200 om, b cross section of the membrane wall the membrane is only 1 pm thick and backed by a rather open support structure of 39 pm that maintains mechanical stability, c view on the outer membrane surface area, showing its high porosity, d view on the rather smooth inner membrane surface area where pore sizes are between 1 and 3 nm. The lower panel shows the detaiied molecular structure of polysulfone (PSu) and polyethersulfone (PES)...

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