Synthesis of dibutyl catalysts - synthesis of dibutyl catalyst - chemical industry

Published: 04th February 2011
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Abstract: p-toluenesulfonic acid, amino acid, strongly acidic cation exchange resin, ferric chloride hexahydrate, pentahydrate stannic chloride, stannous oxide, ferric ammonium copper sulfate, zinc sulfate heptahydrate, sulfate, sodium bisulfate monohydrate, solid super acid, heteropoly acid, and zeolite for catalytic synthesis of dibutyl approach. And the advantages and disadvantages of these catalysts were reviewed.

Keywords: dibutyl sebacate; synthesis; catalyst Key words: O623.624.2 Document code: A Article ID :1672-2191 (2009) 03-0012-0

Dibutyl sebacate is a Plasticizer , Also has a supporting role cold. Because of its non-toxic, can be used for food packaging materials and synthetic food flavors in the [1 2]. It is usually in the presence of concentrated hydrochloric acid by the esterification of sebacic acid and n-butanol is made, or by reacting sebacic acid chloride and alcohol. The strong volatility and strong hydrochloric acid corrosion caused much inconvenience for industrial production, even with concentrated sulfuric acid as catalyst, also has strong side effects caused by corrosive and easy, serious environmental pollution. 80 years since the 20th century, the concept of sustainable development have been proposed after the [3], green chemistry has been on the agenda [4], attention to environmental protection is the current chemical industry should first take into consideration. Many scholars at home and abroad are developing a number of non-toxic, non-corrosive, detachable solid acid catalysts to replace conventional acid catalyst. In particular, more environmentally friendly catalyst by attention. In the synthesis of dibutyl many scholars regard as a catalyst for a research paper knot Cooperation Those studies, in recent years, solid acid catalyst synthesis of dibutyl work for comprehensive coverage and comment.

1. Sulfonic acid catalytic synthesis of dibutyl
1.1 tosylate Tosylate (p-CH3C6H4SO3H.H 2 O) is a solid strong Organic Acid, catalytic activity, storage, transport and easy to use safe, cheap and readily available, is the catalytic synthesis of dibutyl good catalyst, when 0.025mol sebacic acid, 0.20mol butanol, toluene sulfonamide in 0.002 6mol acid under reflux 60 min, dibutyl yield 94.7%, while 0.025mol sebacic acid, 0.3 0 mol n-butanol, in sulfuric acid under reflux 1.0g 30 min, the yield of ester only 84.8%, and when smoking in the product distillation, it is because of the side effects caused by the decomposition by-products. Amount of sulfuric acid increased the reaction time were prone to side effects, and the product yield decreased [5]. Wang Lanzhi and others in this area have been reported, when 0.075mol sebacic acid, 0.45mol butanol, 0.75 g p-toluenesulfonic acid in the catalysis of reflux 2 h, sebacic acid ester-based rate of 96.43%, the yield 89% to 91% [6].

1.2 amino acid Amino acid (H2N-SO2OH) with tosylate, just as a kind of cheap, stable solid, easy to use, except with the strengths of tosylate, it difficult to absorb Chao, slightly soluble or insoluble in organic reaction system with the reaction liquid separation, and therefore the corrosion of equipment smaller, isolated duplicate catalytic properties with catalyst, is a kind of catalyst for industrial application. Han Jinghua with 0.05mol sebacic acid, 0.15mol butanol, 5mL toluene as water, amino acid 0.5g catalyst in refluxing 1.5 h, sebacic acid ester-based rate of 99.0% [7]. As the temperature of a binary acid decarboxylation prone to dehydration, so acid esterification rate and yield of the ester will be a gap. So Wen-Qi Liu, who will 0.025mol sebacic acid, 0.20mol butanol, amino acid catalysis in 0.0077mol refluxing 60min, dibutyl yield of 91.2%. And the duplication of the amino acid catalytic properties [8].

1.3 strong acid cation exchange resin
Strong acid cation exchange resin is a polymer acid, very early reports of catalytic esterification. Advantages: mild reaction does not cause side effects, non-corrosive, non-polluting the environment, high yield and easy post-processing solution, easy and reaction liquid separation, and can re-use, continuous production, most industry value. Synthesis of n, and others using sulfonated polystyrene resin (732) Synthesis of dibutyl sebacate. When 0.025mol sebacic acid, 0.20mol butanol, 1.5g resin in the under reflux 100min, ester yield of 96.2%, the resin used 5 times, the yield is almost unchanged [9].

2. Inorganic Catalytic synthesis of dibutyl

2.1 crystalline ferric chloride

Acid catalyst are described in front of the proton acid catalysis. The inorganic catalyst varies due to different compounds. Including a large class of inorganic materials (such as ferric chloride, stannic chloride, zinc sulfate, copper sulfate) is a cheap and readily available Lewis acid, with the metal atom has Carboxylic acid Coordination of carbonyl oxygen of the air track, and thus the role of catalytic esterification [10], while their weak acidity, the lower the corrosion of equipment, less pollution, fewer side effects, is a good alternative to inorganic acid catalyst. Crystalline ferric chloride (FeCl3.6H 2 O) Fe ( ) electronegativity strong (1.9), Fe3 + outer space orbit with the carboxylic acid carbonyl oxygen coordination, can play a catalytic role in esterification. When sebacic acid, butanol and crystallization of the molar ratio of ferric chloride as 1:10:0.074, the reflux 80min, dibutyl yield of 91.1% [11]; while Wang Lanzhi, who were also reported the catalytic effect of ferric chloride crystallization: When 0.05mol sebacic acid, 0.15mol butanol, 1.0g catalyst, the reflux 2h, sebacic acid conversion rate of 96.73% [of 12]. Therefore, the crystallization of ferric chloride is very important in the catalyst.

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