Butanediol

About: Butanediol is a(n) research topic. Over the lifetime, 850 publication(s) have been published within this topic receiving 11155 citation(s).

Properties of polyether-polyurethane block copolymers: effects of hard segment length distribution

Abstract: Preparation de polymeres a base de poly(tetramethylene oxyde), methylene bis(phenylisocyanate-4,4' et butanediol (ou bis[hydroxy-4butyl] methylene bis[phenylcarbamate]-4,4'

Biodegradable aliphatic polyesters. Part I. Properties and biodegradation of poly(butylene succinate-co-butylene adipate)

Abstract: A series of aliphatic homopolyesters and copolyesters was prepared from 1,4 butanediol and dimethylesters of succinic and adipic acids through a two-step process of transesterification and polycondensation. The synthesized polyesters were characterized by means of nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), viscosity measurements, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and mechanical property measurements. The homopolymer poly(butylene succinate) exhibited the highest tensile strength, which decreased with increasing adipate unit content, passed through a minimum at copolyester composition close to equimolarity and then increased towards the value of poly(butylene adipate). It is interesting to note that in contrast to tensile strength, the elongation at break increased for adipate unit content of 20–40 mol%. The biodegradation of the polymers was investigated by soil burial and enzymatic hydrolysis using three enzymes, Candida cylindracea lipase, Rhizopus delemar lipase, and Pseudomonas fluorescens cholesterol esterase. It appears that the key factor affecting material degradation was its crystallinity.

Fermentation of glycerol to 1,3-propanediol and 2,3-butanediol by Klebsiella pneumoniae

Abstract: Klebsiella pneumoniae was shown to convert glycerol to 1,3-propanediol, 2,3-butanediol and ethanol under conditions of uncontrolled pH. Formation of 2,3-butanediol starts with some hours' delay and is accompanied by a reuse of the acetate that was formed in the first period. The fermentation was demonstrated in the type strain of K. pneumoniae, but growth was better with the more acid-tolerant strain GT1, which was isolated from nature. In continuous cultures in which the pH was lowered stepwise from 7.3 to 5.4, 2,3-butanediol formation started at pH 6.6 and reached a maximum yield at pH 5.5, whereas formation of acetate and ethanol declined in this pH range. 2,3-Butanediol and acetoin were also found among the products in chemostat cultures grown at pH 7 under conditions of glycerol excess but only with low yields. At any of the pH values tested, excess glycerol in the culture enhanced the butanediol yield. Both effects are seen as a consequence of product inhibition, the undissociated acid being a stronger trigger than the less toxic diols and acid anions. The possibilities for using the fermentation type described to produce 1,3-propanediol and 2,3-butanediol almost without by-products are discussed.

Fermentative production of 2,3-butanediol: A review

Abstract: The production of 2,3-butanediol by bacterial species continues to be of great interest because of its varied application. Two bacterial species, Bacillus polymyxa and Klebsiella pneumoniae have demonstrated potential for butanediol fermentation on a commercial scale. Klebsiella pneumoniae, owing to its broad substrate and cultural adaptability, is the most thoroughly investigated organism. It is generally recommended that natural resources of ‘waste’ cellulosic and hemicellulosic substrates be fermented, for the improvement of process economics. The process of diol fermentation is reportedly influenced by various nutritional and environmental parameters. The high boiling-point characteristic of 2,3-butanediol poses serious problems in recovery of diol from fermented slurry. Repeated solvent extraction and countercurrent-stream stripping have been recommended as the methods of choice for diol recovery.

The Microbial Production of 2,3-Butanediol

Abstract: Publisher Summary This chapter provides a comprehensive survey of diol production, including biochemistry, microbiology, and process engineering Two microbial species have demonstrated a potential for diol production on a commercial scale Klebsiella pneumoniae, with broad substrate and environmental adaptability, is the most thoroughly investigated organism The ability to utilize starchy feedstocks is the main advantage of Bacillus polymya Utilization of “waste” cellulosic substrates is generally recommended for improvement of process economics Efficient conversion of hemicellulosic carbohydrates is thus essential The optimal conditions for bioconversion of glucose are clearly distinct from those for xylose This is especially true in terms of culture pH and aeration and to a lesser extent in temperature and nutrient supplementation The most effective process designs may permit separate conditions for the consumption of these sugars In a batch operation, this could be accomplished through a midrun adjustment of key environmental parameters In continuous production, separate reactors could be operated in a series with residence times and conditions established for optimal consumption of the glucose and xylose Recovery of butanediol from fermented broths is especially difficult due to the physical and chemical properties of the compound Solvent extraction and steam stripping appear to be the most effective alternatives at present Incentives to seek renewable alternatives to petroleum-based fuels and chemicals in combination with advances in microbial process efficiency may yet result in an economically viable system for the production of butanediol from biomass resources