Polyester from citric acid

Polyester from Citric acid and Ethvlene Glvcol. Citric acid was mixed with excess ethylene glycol in a small beaker. The clear, colorless solution was maintained at 100 C for 8h, acquiring a pale yellow color. After heating in vacuo at 140 C, a yellow glassy solid was obtained. 

Yang and coworkers did the most efforts on the development of network polyester based on citric acid. " They investigated the reaction of citric acid with a series of aliphatic diols (from 3-16 carbon chains) and polyether diols such as polyethylene oxide (PEG), in which 1,8-octanediol (POC) and 1,10 decanediol (PDC) have been studied the most. 

Different routes for converting biomass into chemicals are possible. Fermentation of starches or sugars yields ethanol, which can be converted into ethylene. Other chemicals that can be produced from ethanol are acetaldehyde and butadiene. Other fermentation routes yield acetone/butanol (e.g., in South Africa). Submerged aerobic fermentation leads to citric acid, gluconic acid and special polysaccharides, giving access to new biopolymers such as polyester from poly-lactic acid, or polyester with a bio-based polyol and fossil acid, e.g., biopolymers . 

PGS is a bioresorbable elastomeric polymer and extensively evaluated for various biomedical applications such as soft and hard tissue engineering and controlled drug delivery [8]. In a similar way, a number of aliphatic polyester elastomers for various biomedical applications were prepared from diacid monomers such as citric acid and a-ketoglutaric acid with aliphatic diols and triols using thermal polycondensation reactions [9-12]. 

This goal was the objective of the present investigation, which is concerned with the preparation of polymers from naturally-occurring, multifunctional hydroxyacids and aminoacids. On degradation such polymers could revert in the body to their original natural products. The natural products chosen for this purpose were malic acid (I), which is an intermediate in the citric acid cycle, and aspartic acid (II), which is a common component of many proteins. High yield synthetic procedures were developed for the conversion of both compounds into cyclic monomers, which could be polymerized to polymers of controlled molecular weights. Malic acid was converted to the 3-lactone and aspartic acid to the 3-lactam, and each was polymerized to its respective polyester and polyamide, as outlined in the equations below ... 

Fig. 10. Biodegradable mulch—kraft paper coated with a polyester made from a reaction product of epoxidized soybean oil and citric acid. The coating reduces the degradation rate and increases wet strength so the mulch can inhibit weed growth for more than 10 weeks. Courtesy of R. Shogren, U. S. D. A.

Mirci L, Boran S, Luca P, Boiangiu V (2003) New citric esters with aromatic content and a complex structure considered for use as tribological fluids. J Synth Lubr 20 39-52 Tsutsumi N, Oya M, Sakai W (2004) Biodegradable network polyesters from gluconolac-tone and citric acid. Macromolecules 37 5971-5976... 

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. 

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