Copolyamide

Co3(P04)2 8H20 CO poisoning Copoly(amide-imides) Copolyamides... 

Technora. In 1985, Teijin Ltd. introduced Technora fiber, previously known as HM-50, into the high performance fiber market. Technora is based on the 1 1 copolyterephthalamide of 3,4 -diaminodiphenyl ether and/ -phenylenediamine (8). Technora is a whoUy aromatic copolyamide of PPT, modified with a crankshaft-shaped comonomer, which results in the formation of isotropic solutions that then become anisotropic during the shear alignment during spinning. The polymer is synthesized by the low temperature polymerization of/ -phenylenediamine, 3,4 -diaminophenyl ether, and terephthaloyl chloride in an amide solvent containing a small amount of an alkaU salt. Calcium chloride or lithium chloride is used as the alkaU salt. The solvents used are hexamethylphosphoramide (HMPA), A/-methyl-2-pyrrohdinone (NMP), and dimethyl acetamide (DMAc). The stmcture of Technora is as follows ... 

Fig. 17. Melting point—composition curves for random copolyamides of nylon-6,6.

There has been considerable research on chlorine-resistant RO membranes (48—52). A poly(/n j -2,5 dimethyl)pipera2inthiofura2anainide used in the presence of low (3 mg/L) concentrations of chlorine resulted in a membrane life of three years (48). A copolyamide hoUow-fiber membrane for use in desalination has been developed that is resistant to 0.5 mg/L chlorine (49). Millipore Corporation has also developed a sulfonated polysulfone member that has desirable chlorine-resistance properties. 

Ethylenimine is known to spontaneously form copolymers with /3-propiolactone274) or cyclic imides275). Crystalline copolyamides of alternating structure were obtained with the latter monomer. 

Block coal, 6 705 Block copolyamide, 79 739 Block copolymerization, 79 762 Block copolymers, 7 645-650 70 436 23 367... 

See also Carbon monoxide (CO) Copolyamides, random, 19 762-763 Copoly(disulfide)s, as electroactive materials, 23 713—714 Copolyestercarbonates, 19 822 Copolyester elastomers, thermoplastic, 20 70-71... 

The trimesoyl chloride could be mixed with isophthaloyl chloride to produce copolyamide barrier layers. Salt rejections toward synthetic seawater improved as the isophthalamide content of the barrier layer Increased. Surprisingly, membrane flux passed through a peak rather than simply declining as a function... 

Tests were also run with simulated brackish agricultural drainage water, as illustrated in Table 4. A feedwater composition containing sodium, calcium, chloride, sulfate, and bicarbonate ions was prepared in such a way as to duplicate the water in the Mohawk-Wellton drainage canal at Yuma, Arizona. Salt rejections were relatively poor toward this synthetic feedwater, but when this water was line-softened and acidified to pH 5.5 with sulfuric acid, salt rejection of the 90 10 copolyamide improved markedly. However, the membrane s water flux declined by nearly 50 percent. Salt rejection and flux were found in this and other examples to be markedly dependent on pH. As the pH approached the pKa of... 

We report here that polyethylene adipate (PEA) and polycaprolactone (PCL) were degraded by Penicillium spp., and aliphatic and alicyclic polyesters,ester type polyurethanes, copolyesters composed of aliphatic and aromatic polyester (CPE) and copolyamide-esters (CPAE) were hydrolyzed by several lipases and an esterase. Concerning these water-insoluble condensation polymers, we noted that the melting points (Tm) had a effect on biodegradability. 

Hydrolysis of Copolyamide-esters (CPAEs) by Lipase (jj,). CPAEs were synthesized by the amide-ester interchange reaction between polyamide and polyester. The length of the polyamide blocks was measured after hydrolysis of ester bonds in CPAE by alkali at 30 C. The infrared spectra after hydrolyzing ester bonds on CPAEs showed that the ester bonds were almost completely removed. The molecular weight distribution of polyamide blocks was examined by GPC (Table II). The following samples were used CPAE-1 (reaction time for synthesis, 1 hr) and CPAE-2 (reaction time, U hr) composed of nylon 6 and PCL at a 50/50 molar ratio, CPAE-3 (reaction time, 1 hr) and CPAE-U (reaction time,... 

Statistical copolymerization of ethylene glycol and 1,4-butanediol with dimethyl ter-ephthalate results in products with improved crystallization and processing rates compared to poly(ethylene terephthalate). Polyarylates (trade names Ardel, Arylon, Durel), copolymers of bisphenol A with iso- and terephthalate units, combine the toughness, clarity, and proce-sibility of polycarbonate with the chemical and heat resistance of poly(ethylene terephthalate). The homopolymer containing only terephthalate units is crystalline, insoluble, sometimes infusible, and difficult to process. The more useful copolymers, containing both tere- and isophthalate units, are amorphous, clear, and easy to process. Polyarylates are used in automotive and appliance hardware and printed-circuit boards. Similar considerations in the copolymerization of iso- and terephthalates with 1,4-cyclohexanedimethanol or hexa-methylene diamine yield clear, amorphous, easy-to-process copolyesters or copolyamides,... 

A good example of template copolycondensation has been described by Ogata et al Copolycondensation of 2,6-dimethyl pyridine dicarboxylate and dimethyl adipate with hexamethylene diamine was carried out in the presence of polysaccharide - Pullulane (mol. weight 30,000) used as a template. The reaction was carried out in DMSO at 60 C. It was found that the content of 2,6-dimethyl pyridine dicarboxylate units in the copolyamide, determined by NMR analysis, increased in the presence of Pullulane in comparison with the amount obtained in the absence of the template. This effect can be explained by preferential adsorption by the template of monomer having pyridine groups in comparison with the adsorption of dimethyl adipate. A set of experiments was carried out under the same conditions, but in the presence of poly(acrylonitrile) instead of Pullulane. The composition of copolyamides was the same as in copolycondensation without the template. 

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