Pebax

Product Pebax Pebax Pebas Grilamid Ely 60 Siltem ... 

A wide range of polyether-polyamide block copolymers were first offered by Atochem in 1981 under the trade name Pebax. These are made by first producing a low molecular weight polyamide using an excess of dicarboxylic acid at a temperature above 230°C and under a pressure of up to 25 bar. This is then combined with a polyether by reaction at 230-280°C under vacuum (O.l-lOTorr) in the presence of a suitable catalyst such as Ti(OR)4. 

Table 18.16 Selected properties of polyether-polyamide block copolymers of the Pebax type (After Deleens, 1987)...

Block copolymers can contain crystalline or amorphous hard blocks. Examples of crystalline block copolymers are polyurethanes (e.g. B.F. Goodrich s Estane line), polyether esters (e.g. Dupont s Hytrel polymers), polyether amides (e.g. Atofina s Pebax grades). Polyurethanes have enjoyed limited utility due to their relatively low thermal stability use temperatures must be kept below 275°F, due to the reversibility of the urethane linkage. Recently, polyurethanes with stability at 350°F for nearly 100 h have been claimed [2]. Polyether esters and polyether amides have been explored for PSA applications where their heat and plasticizer resistance is a benefit [3]. However, the high price of these materials and their multiblock architecture have limited their use. All of these crystalline block copolymers consist of multiblocks with relatively short, amorphous, polyether or polyester mid-blocks. Consequently they can not be diluted as extensively with tackifiers and diluents as styrenic triblock copolymers. Thereby it is more difficult to obtain strong, yet soft adhesives — the primary goals of adding rubber to hot melts. 

There are five types of thermoplastic rubbers currently available. These are based on (i) Olefinics (e.g. Alcryn, Santoprene) (ii) Polyiuethanes (e.g. Elas-tollan, Caprolan, Pellethane) (iii) Polyesters (e.g. Hytrel, Amitel) (iv) Styrenics (e.g. Solprene, Cariftex) and (v) Polyamides (e.g. Pebax, Dinyl) Some typical properties are given in Table 1.4. 

Commercial melt-mixed blends of EPDM and PP, dynamically vulcanized, Monsanto (Santroprene) Polyamide TPE, Atochem (Pebax)... 

The composition of the test sample was compared to literature values for commercial PA-12/TMG block copolymers marketed under the trade name PEBAX . PEBAX 5533 typically has a PA-12 content of 62wt%, and PEBAX 6333 has a PA-12 content of 76wt%. From the NMR data, the test sample has a composition most similar to PEBAX 6333. 

As mentioned above, the composition of catheter sample 1 was consistent with PEBAX 6333 . Similar results were obtained for catheters 2, 4, and 5, as shown in Table 14. By contrast, catheter samples 3 and 6 appear to be composed of PEBAX 5533 . Therefore, it was concluded that the breaking catheters were made from a different material. 

Pebax, commercial block copolymer, 7 648t Pebble mills, 25 64 Pebble quicklime, 15 28 Peclet numbers (Pe), 2 63 10 763 22 746 25 686t, 687t 25 279. See also Mass transfer Peclet number (PeMT) axial dispersion in bubble tray absorbers, 2 89... 

Montac, Pebax, Orevac, Vestamide, Grilamid, and Grilon. 

Other important thermoplastic elastomers are the multiblock polyetheresters (trade names Hytrel, Lomod) and polyetheramides (trade names Pebax, Estamid, Grilamid). 

Product Pebax 2533 Pebax 4033 Pebas 6333 Grilamid Ely 60 Siltem STM1500... 

Polyamide-polyether block copolymers (Pebax , Elf Atochem, Inc., Philadelphia, PA) have been used successfully with polar organics such as phenol and aniline [32-34], The separation factors obtained with these organics are greater than 100, far higher than the separation factors obtained with silicone rubber. The improved selectivity reflects the greater sorption selectivity obtained with the polar organic in the relatively polar polyamide-polyether membrane. On the other hand, toluene separation factors obtained with polyamide-polyether membranes are below those measured with silicone rubber. 

Figure 1.2 Atomic representation of a surface model of Pebax/30%KET with water [17].

Pebax is a thermoplastic elastomer PA is an aliphatic polyamide hard block (e.g., nylon-6, nylon-12) and PEG is an amorphous polyether (polyethylene oxide (PEO) or polytetramethylene oxide (PTMO)) soft block (Scheme 4.2). 

Scheme 4.2 Chemical structure of Pebax . Reprinted from Ref. [56], with permission from Elsevier...

The above thermal analysis studies demonstrated the enhanced thermal stability of POSS materials, and suggested that there is potential to improve the flammability properties of polymers when compounded with these macromers. In a typical example of their application as flame retardants, a U.S. patent39 described the use of preceramic materials, namely, polycarbosilanes (PCS), polysilanes (PS), polysilsesquioxane (PSS) resins, and POSS (structures are shown in Figure 8.6) to improve the flammability properties of thermoplastic polymers such as, polypropylene and thermoplastic elastomers such as Kraton (polystyrene-polybutadiene-polystyrene, SBS) and Pebax (polyether block-polyamide copolymer). 

The resulting blends were shown to possess enhanced flammability and mechanical properties. The cone calorimeter data shown in Table 8.1 indicate that the highest reduction in the PHRR was obtained for the Pebax system where a reduction of 65%-70% in PHRR was reported. The reduction in heat release was obtained by enhanced char formation. The char reduces the escape of small volatile molecules to the gas phase, which in turn reduces the amount of heat release feedback to the polymer surface. 

The elastomeric polyamides are relatively expensive (for Pebax about 10.00/kg for low-quality grades and about 17.00 for high-quality grades for Grilamid ELY the prices are almost double), but because in finished articles the density is lower, the wall thickness much lower, and the molding cycles shortened, the final cost may be lower than that of corresponding goods in rubber. 

Ethylene Glycol Methyl Ether 111-43-3 Propyl Ether 113055-64-4 Pebax 6312... 

Fig. 4.15 Solvent-exclusion contribution to image contrast is demonstrated with scanning force data acquired on a co-block-polyethylene glycolpoly amide (Nylon-12) surface (PEBAX 1,074), prepared by melting/resolidification. (a) Topographic image in water, methoxy tip termination (15 x 15 pm2) (b) friction LFM image in water, methoxy tip termination (15 x 15 pm2) (c) topographic image in water, amide tip termination (7.5 x 7.5 pm2), (d) friction image in water, amide tip termination (7.5 x 7.5 pm2). (Reprinted with permission from [32]. Copyright 1996. American Chemical Society.)...

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