Polyhexamethylene adipate

Figure U. Effects of molecular weight of polyester on the hydrolysis by lipases. Three kinds of polyesters were used PCL-diol ( ), polyhexamethylene adipate (O ) and their copolyester ( ). The dashed line shows the result when one tenth enzyme concentration was used.

SMPU is usually synthesized from long-chain polyols, diisocyanate and short-chain extenders. The polyols that have typically been used to date include polycaprolactone (PCL), polytetramethylene ether glycol (PTMG), polybutylene adipate (PBA), polyhexamethylene adipate (PHA) and polylactic acid (PLA)... 

Waste nylon-6,6 was washed in a diluted commercial detergent solution at 100°C for 0.5 h and then rinsed twice with water to remove any finishes present. The washed nylon-6,6 was then reacted with molten adipic acid for 1.5 h or more at a temperature of 175°C with a weight ratio of nylon-to-adipic acid of 0.15 1. The molten product was then exposed to steam at a temperature of 230-233°C to remove any stabilizers present. The acidolysis product was then hydrolyzed with water at a temperature of 204°C under autogenous pressure for 0.5 h or longer with a ratio of water to acidolysis product of 0.50 1 (w/w). The hot solution was then filtered at 100°C to remove any titanium dioxide present. The filtered product was then mixed with HMDA to neutralize any excess acid present. The solution was then filtered to remove any solids. A 50% by weight aqueous solution of HMDA was added to the filtrate, and under standard polymerization conditions, polyhexamethylene adipamide (nylon-6,6) was produced. 

On February 28, 1935, Carothers project succeeded beyond anyone s wildest dreams. The cheerful, lively Frenchman Berchet produced a superpolymer made from chemicals derived from cheap benzene, a by-product of coal later they would be made from petroleum. A filament teased from Berchet s polymer was, despite its lowly origins, pearly and lustrous. And when it was tested, it proved to be spinnable. Its code name was 6-6 because both its reactants—hexamethylene diamine and adipic acid—had six carbon atoms. Technically, the filament was polyhexamethylene adipamide, a long-chain polymer similar in structure to proteins. It became world-famous as nylon. 

Polyethylene adipate Polyethylene suberate Polyethylene azelate Polyethylene sebacate Polyethylene decamethylate Polytetraunethylene succinate Polytetramethylene adipate Polytetramethylene sebacate Polyhexamethylene sebacate Poly-2,2-dimethyItrimethylene succinate... 

Polycaprolactone (PCL) Poly-cis-2-butene adipate Poly-cis-2-butene sebacate Poly-trans-2-butene sebacate Poly-2-butyne sebacate Polyhexamethylene fumarate Poly-cis-2-butene fumarate Poly t e t r ame t hy Icy c lobut ane succinate... 

Figure 6. Relationship between Tm and the biodegradability of polyesters by R> delemar (a) and R> arrhizus (b) lipases, and PEA-degrading enzyme from Penicillium sp. strain ll+-3 (c). PESu polyethylene suberate PEAz polyethylene azelate PESE polyethylene sebacate PEDe polyethylene decamethylate PBS polytetramethyl-ene succinate PBA polytetramethylene adipate PBSE polytetra-methylene sebacate PHSE polyhexamethylene sebacate PPL poly-propiolactone.

Nylon 66. The word nylon was established as a generic name for polyamides, one class of the new high molecular weight linear polymers. The first of these, and the one still produced in the largest volume, was nylon 66 or polyhexamethylene adipamide. Numbers are used following the word nylon to indicate the number of carbon atoms contributed by the diamine and dicarboxylic acid constituents, in this case hexamethylenediamine and adipic acid, respectively. 

PA-66 Poly(hexamethylene diamine-adipic acid), polyhexamethylene-adipamide PA-6IT6 Poly(caprolactam-co-hexamethylene diamine-isophthalic/terephthalic... 

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