A kind of method for preparing alkyl glycoside with the microwave-ultrasonic concerted catalysis
Technical field
The invention belongs to the preparation field of tensio-active agent, particularly a kind of method for preparing alkyl glycoside with the microwave-ultrasonic concerted catalysis.
Background technology
Alkyl glycoside (alkyl polyglycoside, APG for short) be a class novel surfactant of developing beginning of the nineties late 1980s, many advantages with nonionic and anion surfactant, not only low, active high, the strong detergency of surface tension, foam are abundant fine and smooth and stablize, and good with other tensio-active agent compatiblenesies,, the advantages such as biological degradation good, nontoxic, consistency good, environmentally safe little to the skin eye irritation.Be widely used in washing composition, industrial emulsion agent, makeup, food and medicine trade.Because its synthesis material and performance characteristic are described as mildness of new generation " green " tensio-active agent, it is the unique kind that really deserves to be called " world-class " tensio-active agent after LAS, AES and AEO.
The synthetic method of APG has the Betamethasone Ketal structures alcoholysis method of the glucosides method (two-step approach) that turns, direct glycosidation method (single stage method), enzyme catalysis method, former ester method and sugar.Turning the glucosides method is that glucose first reacts with butanols, and then reacts with higher alcohols, obtains the glucosides of higher alcohols.United States Patent (USP) (US 5374716), Chinese patent (CN92102625.0, CN200510096464.8, CN98813130.7) all adopt this method to prepare alkyl glycoside.Turn that the technical process of glucosides method is long and poor product quality is eliminated just gradually.Directly the glycosidation method is that glucose reacts under the effect of an acidic catalyst with higher alcohols, saved and turned two pure exchange steps in the glucosides method, technique is simplified, in product, without the low alkyl group glucosides, exist, existing batch production device adopts this kind of method more, but in direct glycosidation method technique, glycosylation reaction is two reaction systems of a solid-liquid, and the solubleness of glucose in higher alcohols is minimum, make speed of response slow, and sugar easily lump.For addressing these problems, China Daily Chemical Industry Research Institute adopts the patented technology (CN 200410064505.0) of independent research, designed the special-purpose homogenizing mill with conveying, crushing function, make the sugar of reactor bottom remain flow state, be difficult for being deposited on for a long time bottom, accelerated speed of response.Shao Baihua etc. (research of Synthesis of Dodecyl Glucoside at Normal Pressure. chemical engineer .2000.80 (5): 15-17.) adopt the technique that is pre-mixed and adds dispersion agent, increase the solubleness of glucose in higher alcohols, make the reaction times shorten 20-30min.Though above method has certain effect, larger limitation is all arranged.
Summary of the invention
The present invention seeks to for the existing problem of prior art, a kind of synthesizing alkyl polyglycoside catalyzed method of microwave-ultrasonic of utilizing is provided.It is fast that the method has speed of response, and transformation efficiency is high, to advantages such as environmental influence are little.
Technical scheme provided by the invention is:
A kind of method for preparing alkyl glycoside with the microwave-ultrasonic concerted catalysis follows these steps to carry out:
A, by mol ratio, be 1: the glucose of 2-10 and fatty alcohol add in container and stir, and under microwave heating, Ultrasonic Radiation condition, 5min is warmed up to 110-120 ℃, absolute pressure 1.5-6.5KPa, vacuum hydro-extraction 15min;
B, add an acidic catalyst, under absolute pressure 1.5-6.5KPa, reaction 30-90min;
After c, reaction finish, when temperature is reduced to 50-80 ℃, with in neutralizing agent and an acidic catalyst to pH=8-11;
D, increase the temperature to 120-200 ℃, absolute pressure 1.5-6.5KPa, carry out the underpressure distillation dealcoholysis, obtains the thick product of APG.
Described an acidic catalyst is one or more in sulfuric acid, hydrochloric acid, phosphoric acid, sodium pyrosulfate, alkyl benzene sulphonate (ABS), tosic acid, phospho-wolframic acid, citric acid, storng-acid cation exchange resin.
The 0.5-5% that the consumption of described an acidic catalyst is glucose weight.
Described fatty alcohol carbon chain lengths is 8-18.
Described neutralizing agent is sodium bicarbonate, sodium hydroxide, sodium carbonate and one or both mixture thereof.
Described ultrasonic power 200W-700W; Microwave heating power is 100-600W.
The invention has the beneficial effects as follows, utilize microwave-ultrasonic synthesizing alkyl polyglycoside catalyzed, compared with prior art have following characteristics: (1) speed of response is fast, and the reaction times is short.Under the conventional heating condition, synthesizing alkyl polyglycoside needs 5-6h, and adopting microwave heating to prepare alkyl glycoside needs 30-60min.(2) inversion rate of glucose is high, can reach 99%.
Embodiment
The technology of alkyl glycoside for preparing with the microwave-ultrasonic concerted catalysis of the present invention is by microwave heating, the effective combination of Ultrasonic Radiation.Microwave heating is compared with traditional type of heating, and its advantage is that microwave heating has very strong penetration, can greatly improve speed of response, reduces reaction activity, is a kind of eco-friendly novel synthetic technology.Ultrasonic wave is the very wide a kind of high frequency mechanical wave of range of frequency, is the mechanical energy of concentrating, and utilizes hyperacoustic mechanical effect can reduce the caking of glucose, improves the dispersiveness in alcohol, can make inhomogeneous reaction carry out smoothly.Fully utilize the two plurality of advantages, compared with the prior art obvious technical progress and difference are arranged: speed of response is fast, and Reaction time shorten, energy-efficient greatly, and transformation efficiency is high.In synthetic, reaction equation is as follows:
Embodiment 1
Add 54gC in the 100mL three-necked bottle
12/14fatty alcohol, 10g glucose, be placed in the microwave reactor central position, installs the electric stirring bar, design temperature 5min is warmed up to 115 ℃, and then vacuum hydro-extraction 15min adds the 0.1g alkyl benzene sulphonate (ABS), set the microwave irradiation power of 150W, under the condition of absolute pressure 6.0KPa, reaction 30min.Reaction treats that temperature is reduced to 80 ℃ after finishing, and with sodium bicarbonate, is neutralized to pH=8, increases the temperature to 140 ℃, and absolute pressure 6.5KPa, carry out the underpressure distillation dealcoholysis, obtains the thick product of APG, transformation efficiency 69%.
Embodiment 2
In the 100mL three-necked bottle, add 54gC
16/18fatty alcohol, 12g glucose, be placed in the microwave reactor central position, installs the electric stirring bar, 5min is warmed up to 118 ℃, and then vacuum hydro-extraction add the 0.1g sodium pyrosulfate, set the microwave irradiation power of 400W, under the condition of absolute pressure 6.5KPa, reaction 60min.Reaction treats that temperature is reduced to 70 ℃ after finishing, and with sodium carbonate, is neutralized to pH=8.5, increases the temperature to 130 ℃, and absolute pressure 6.5KPa, carry out the underpressure distillation dealcoholysis, obtains the thick product of APG, transformation efficiency 95%.
Embodiment 3
In the 100mL three-necked bottle, add 60gC
8/10fatty alcohol, 10g glucose, be placed in the microwave reactor central position, installs ultrasonic unit, 5min is warmed up to 120 ℃, vacuum hydro-extraction, then add the 0.5g tosic acid, sets ultrasonic power 600W, magnetic agitation, the microwave irradiation power of 500W, under the condition of absolute pressure 6.0KPa, reaction 30min.Reaction treats that temperature is reduced to 60 ℃ after finishing, and with sodium hydroxide, is neutralized to pH=9, increases the temperature to 135 ℃, and absolute pressure 4.5KPa, carry out the underpressure distillation dealcoholysis, obtains the thick product of APG, transformation efficiency 99%.
Embodiment 4
In the 100mL three-necked bottle, add 60gC
12/14fatty alcohol, 10g glucose, be placed in the microwave reactor central position, installs ultrasonic unit, 5min is warmed up to 115 ℃, vacuum hydro-extraction, then add the 0.1g tosic acid, sets ultrasonic power 200W, magnetic agitation, the microwave irradiation power of 400W, under the condition of absolute pressure 6.2KPa, reaction 90min.Reaction treats that temperature is reduced to 70 ℃ after finishing, and with sodium hydroxide, is neutralized to pH=9, increases the temperature to 135 ℃, and absolute pressure 3.5KPa, carry out the underpressure distillation dealcoholysis, obtains the thick product of APG, transformation efficiency 97%.