Polyethylene glycol—adipic acid polyester

A polyester of adipic acid and a mixture of isomer polyethylene glycols shows good compatibility with cellulose esters, chlorinated rubber, and PVC. 

Hyperbranched water-soluble polyesters containing polyethylene glycol and adipic acid were prepared by Stumbe [1] and used as additives in paints. 

In standard classification for vinyl plastics used in biomedical applications, a plasticizer is specified with prefix letter The letter is followed by a number from 1 to 14 which characterizes the type of plasticizer (e g., 1 - none, 2 - adipic acid derivative, 3 -azelaic, 4 - benzoic, 5 - citric, 6 - isophthalic, 7 - myristic, 8 - phosphoric, 9 - phthalic, 10 - sebacic, 11 - terephthalic, 12 - poly ether, 13 - polyethylene glycol, 14 - polyesters, 999 - other). The second letter specifies secondary plasticizer (e.g., A - none, B - alkyl epoxy stearates, C - epoxidized tall oil, D - epoxidized soybean oil, E - epoxidized linseed oil, F - epoxidized sunflower oil, Z - other). This classification is used to guide design engineers. Classification is not applicable to long-term implants. If there is a conflict between provisions of this standard and detailed specification for a particular device, the latter takes precedence. 

A full analysis of a known polyurethane composition containing 1,5-naphthalene diisocyanate and polyethylene adipate gave results in which the total adipic acid-glycol polyester content was of the order of 77% and the 1,5-naphthalene diisocyanate 15 5%. The added total is thus 92 5%, leaving 7 5% unaccounted for, but bearing in mind the complexity of the analysis, this must be considered a relatively satisfactory result. 

Polyester polyols are an important class of urethane raw materials, with applications in elastomers, adhesives, etc. They are usually made from adipic acid and ethylene glycols (polyethylene adipate) ... 

In addition to MA, phthalic anhydride, and ethylene glycol, other common intermediates used for the production of unsaturated polyesters are fumaric acid, isophthalic acid, adipic acid, propylene glycol, diethylene glycol, and dipropylene glycol. Table 12.1 provides a summary of both common and specialty building blocks used in polyesters and contributions made by these intermediates to the properties of the products. Recycled polyethylene terephthalate beverage bottles may one day become an important raw material for unsaturated polyester resin production, providing an alternative for a substantial part of the petroleum-based intermediates. 

The direct polyesterification reaction of diacids with glycols is the most important industrial synthetic route to polyester polyols. The second most important synthetic route is the transesterification reaction between dimethyl esters of dicarboxylic or dibasic acids (dimethyl adipate, dimethyl terephthalate, dimethyl carbonate or even polyethylene terephthalate) and glycols (reaction 8.2) [1, 3-8]. 

Polyester, saturated n. Any polyester in which the polyester backbone has no double bonds. The class includes low-molecular-weight liquids used as plasticizers and as reactants in forming urethane polymers and linear, high-molecular-weight thermoplastics such as polyethylene terephthalate. Usual reactants for the saturated polyesters are (1) a glycol such as ethylene-, propylene-, diethylene-, dipropylene-, or butylene glycol (2) An acid or anhydride such as adipic, azelaic, or terephthalic acid or phthalic anhydride. Some saturated, branched polyesters are used in high-temperature varnishes and adhesives. 

Two polyesters in particular are used in the manufacture of Vulkollan, i.e. Desmophen 2000 and Desmophen 2001 (see Table 5.13). Desmophen 2000 is a linear polyethylene adipate with an approximate molecular weight of 2000 and a low acid number, and can be considered to be the normal polyester to be used. Demophen 2001 is again a linear polyester with a similar low acid number but consists of a mixed glycol polyester. The effect of using this mixed polyester is to reduce the crystallinity and make the final product more suitable for use at lower temperatures. At normal temperatures, however, Desmophen 2001 products have slightly inferior properties to products from Desmophen 2000. 

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