AMIDE POLYMER

Diacids or carbonates are used with alkyleneamines to make amide polymers (27,28). 

One of the oldest and (still) eommercially most important polymers is nylon. Actually, nylon does not refer to a single polymer, but rather to an entire class of amide polymers or polyamides . Two of the most common are Nylon 6 and Nylon 6,6. 

Limited testing on chlorine sensitivity of poly(ether/amidel and poly(ether/urea) thin film composite membranes have been reported by Fluid Systems Division of UOP [4]. Poly(ether/amide] membrane (PA-300] exposed to 1 ppm chlorine in feedwater for 24 hours showed a significant decline in salt rejection. Additional experiments at Fluid Systems were directed toward improvement of membrane resistance to chlorine. Different amide polymers and fabrication techniques were attempted but these variations had little effect on chlorine resistance [5]. Chlorine sensitivity of polyamide membranes was also demonstrated by Spatz and Fried-lander [3]. It is generally concluded that polyamide type membranes deteriorate rapidly when exposed to low chlorine concentrations in water solution. 

VP copolymenzation [VINYL POLYMERS - N-VINYL AMIDE POLYMERS] (Vol 24)... 

Lyotropic polymers consisting solely of ring structures are also known, and are exemplified by poly(p-phenylene benzobisthiazole) (IV), which forms a nematic phase in several strongly protonating acids including polyphosphoric acid. Its synthesis and application, like those of the aromatic amide polymers, are discussed later. 

Scheme 6.6. Procedures for the preparation of poly(aryl amide) polymers. The carboxylic acid terminated polymers exhibited lyotropic liquid crystalline behavior.

An ester-amide polymer was prepared by ROP, catalyzed by Porcine pancreatic lipase (5 wt %) of a six-membered cyclic depsipeptide, 3(S)-isopropylmorpholine-2,5-dione (IPDM), in bulk at 100°C, with M = 17500, M = 18500, and 66% yield [103]. 

Pebax . [Atochem N. Am. Atochem UK] Polyether block amide polymers, extrusion/molding grade polymer used in sport, automobile, elec7electionics, medical, agriculture, and mechanical handling industries, adhesives. 

USE In antifouling compositions as emulsifier and dis -persing agent as antioxidant in lubricating oils as combustion-improver in fuel oils as stabilizer for amide polymers as catalyst. 

However, despite its widespread popularity in material science, PNIPAM has inherent disadvantages such as an irreversible phase transition and, for short polymers, a significant influence of end-groups on the thermal behavior. Moreover, strictly speaking, PNIPAM is not a bio-inert polymer. Indeed, the presence of multiple secondary amide functions in the molecular stracture of PNIPAM may lead to the formation of cooperative H-bonding interactions with other amide polymers, in particular with proteins. Thus, the design of new types of thermoresponsive polymers is a cracial topic in contemporary polymer chemistry. 

In nature, hydrolases are used to degrade or hydrolyze particular functionalities, e.g., lipases to hydrolyze esters and proteases to hydrolyze peptide (amide) linkages (J). It is well known that under suitable reaction conditions lipase can catalyze reverse reactions to form polyesters 4,5). Some of these methods have relied upon the use of organic solvents, whereas others are solvent-free processes. However, it is not previously known that proteases can catalyze reverse reactions to form amide polymers. 

The amide solvent serves also as an acid acceptor for the hydrogen chloride produced in the reaction. Other polar aprotic solvents such as dimethyl-formamide (DMF) and dimethylsulfoxide (DMSO) cannot be used because they react significantly with acid chlorides [Id]. Amide solvents can interact efficiently with the aromatic amide polymers of moderately high molecular weight formed during the condensation reaction, and therefore provide maximum swelling. Consequently this allows the macromolecular chain to continue to grow until completion. Many of the key factors required in polycondensation... 

Little dichroism was shown at 1658 cm in the polymers containing more amide groups. The magnitude of this band was probably due to the additional absorbance of hydrogen-bonded side-chain amide groups that absorb in the region of 1650 cm (Bellamy, 1956). The position of this band lends support to the presence of side-chain amide associations in the solid amidated polymers. 

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