The preparation method of trihydroxybutyl cellulose ether and synthetic
Technical field
The preparation that the invention belongs to the four carbon side chain ether of cellulose that contain three hydroxyl butyl reaches synthesizes, and it belongs to technical field of polymer chemistry, and its national patent classification number is C08.
Background technology
Cellulose ethers is the derivatived cellulose that natural cellulose obtains through chemical modification.Because its abundant raw material, various in style, excellent property and being widely used in the industrial production such as building, cement, oil, food, weaving, washing composition, coating, medicine, papermaking, military project and electronic component has become the industrial goods of producing in the world wide.The ether of cellulose of suitability for industrialized production and application is divided into by ionization at present: a. ionic, as CMC (carboxymethyl cellulose); B. non-ionic type, as MC, HEC, HPC, HPMC etc.; C. ionic and non-ionic type mixed ether.
Contain in the side chain in institute's synthetic ether of cellulose-OH HEC arranged, HPC, HPMC etc., do not contain two keys in the product, or compare with raw cellulose, the content of its hydroxyl all has reduction largely, can synthesize and contain that unsaturated double-bond or its hydroxy radical content are not less than even the hydroxy radical content that is higher than the pristine fibre element is the problem that people are concerned about always, because these ether of cellulose performances are more superior, functional stronger, it is wider to carry out chemical modification, and material can be widely used in high added value chemical fields such as military project after the modification.But these ethers synthetic has bigger difficulty and complicacy, its reason be draw two keys on it or hydroxyl much more active than hydroxyl on the glucosyl residue of pristine fibre element, especially bring up to four carbon atom when above when chain length, the etherification reaction process becomes and becomes increasingly complex.
The synthesizing new ether of cellulose to improve the kindliness of cellulose macromolecule, makes and contains unsaturated double-bond on the ether of cellulose side chain or improve on its macromolecular chain-the OH number, and is significant.The side chain of many carbon plays " internal plasticization " effect in cellulose macromolecule, compare simultaneously with the primary cellulosic molecule, its-the OH number is constant even increase, can synthesize have thermoplasticity, energy is higher than nitrocellulosic novel containing can tackiness agent.At Russian Д in 1977. А. Ш л а о в, Γ in 1980. А. Л о б а ш о в а all reported own the catalysis of Mierocrystalline cellulose thermoplasticity ether synthetic aspect progress of research.People such as the fifties U.S. J.B.Mckelvey have carried out the synthetic of the polynary alcohol derivate of Mierocrystalline cellulose by the reaction of Mierocrystalline cellulose and diepoxybutane, but because disproportionation reaction is arranged, and the derivative that generates makes macromole chain extension to some extent, and this technology is not adopted by the people so far.
The preparation method who the invention belongs to a kind of trihydroxybutyl cellulose ether reaches synthetic.
Summary of the invention
The present invention adopts natural cotton, wood cellulose is through the alkalization of 18%~20%NaOH aqueous solution, squeezing and slaking, then at specific inductivity at the organic solvent between 1.89~2.57 and having under the condition that adds 0.2%~5% (quality) oxidation inhibitor, under 50~90 ℃ temperature ranges and stirring, add the epoxy butylene it is carried out etherificate, pass through decant again, neutralization, washing and process such as drying obtain molar substitution at 0.5~1.8 hydroxyl butylene ether of cellulose, obtain trihydroxybutyl cellulose ether through hydroxylation again in peracid solutions, preparation technology and study route are as follows:
Synthetic total thinking of monohydroxy butylene ether of cellulose and trihydroxybutyl cellulose ether is:
Adopt 1,2-epoxy butylene carries out etherificate to Mierocrystalline cellulose, at first will alkalize to Mierocrystalline cellulose, i.e. alkali activation in advance, make itself and epoxy butene reaction then in the ebullient organic solvent, preparation process is in specific time, carries out in the reactor of band condensation reflux unit.Neutralization, boiling then, solidify, decon, carry out drying treatment again, in acetone, extract at last.Compare with common ether of cellulose is synthetic, the preparation difficulty of novel ether is to contain active pair of key on reaction mass and the intermediate, does not take measures can not get designed product.
Synthetic monohydroxy butylene Mierocrystalline cellulose belongs to heterogeneous liquid-solid reaction, is to utilize soda cellulose to carry out etherification reaction in thinner, and preparation process comprises following several stages:
1) cellulose activation: with 18%~33%NaOH aqueous solution Mierocrystalline cellulose being alkalized, is under 15 ℃~25 ℃ conditions, handles 2~24h, and unnecessary alkali lye (press ratio 2.5~3.0), the experienced 20~80min of recurring are removed in the back squeezing.
2) preparation of reaction solution: before this with 1,2-epoxy butylene is added in the organic medium of selection, forms solution, adds oxidation inhibitor then.1, the concentration of 2-epoxy butylene in thinner is 7%~30% (quality), and occurrence depends on wants the cellulosic molar substitution of synthetic hydroxyl butylene.The reactivity coefficient of cellulosic material is 6~8 scopes (Gu liquid/than) preferably, and the content of antioxidant is 0.5%~5% (quality).
3) the cellulosic preparation of hydroxyl butylene: the soda cellulose of handling well is added in the medium of organic solvent, the organic solvent specific inductivity is 1.84~2.57, and boiling point is 50~115 ℃ of scopes.Synthetic is in the regular hour, by means of what carry out under reflux condensation mode, the continuous ebullient condition.
4) the hydroxyl butylene is cellulosic separates out and neutralizes: finish by reaction solution decant method.Use the product in 5%~10% acetum neutralization reactor then, be heated again until its change condensed state.Resulting hydroxyl butylene Mierocrystalline cellulose will use hot water (or pure water mixed solvent) repeatedly to wash at last, filters purifying with B.
5) extraction and impurity and the water driven away in the product: be in pure water, to carry out.Leach and dry and obtain bright having yellowish glassy mass, have stronger wetting ability, in dry sealed vessel, preserve.
6) the cellulosic hydroxylation process of hydroxyl butylene: in the peroxyformic acid medium for preparing in advance, hydroxyl butylene Mierocrystalline cellulose is carried out hydroxylation.The concentration of this process active oxygen is in 1~1.7mol/L range.Reaction is intermittently carried out under the stirring condition down at 25 ℃.
Synthesize under adding phenols additive and carry out, generally select Resorcinol, pyrocatechol and p-ten.-butylcatechol, its objective is the chemically reactive of raising reagent and the molar substitution of product, the etherification reaction degree is improved.
Organic medium can be selected pentane, hexane, benzene, hexanaphthene, heptane and toluene, and epoxy butylene/cellulosic mol ratio is 2~10, and temperature of reaction is 65 ℃~90 ℃ scopes.
Specific embodiment
Embodiment 1: the polymerization degree is at 900 pulverizing gossypin 10g, utilizes 30% the NaOH aqueous solution to carry out the normal temperature alkalization, the 30~80min that under the condition of strong mixing, alkalizes, and unnecessary alkali lye (press ratio about 2.7) is removed in squeezing, places slaking 20~30min again.In reactor, add E heptane 150g, and add the 0.15g p-ten.-butylcatechol as additive, adding the good soda cellulose of oneself alkalization then stirs, carry out twice of vacuum nitrogen filling emptying simultaneously, behind the 5min under continuous stirring condition, in 20min, add 30g epoxy butylene, temperature is brought up to 60 ℃ of reaction 60min, be warmed up to 80 ℃ of reaction 180min again, the PH=7.0 after peroxyacetic acid neutralizes, with pure water mixed solvent washing repeatedly, drying obtains the faint yellow solid powder, i.e. hydroxyl butylene ether of cellulose again, in the peroxyformic acid medium for preparing in advance, it is carried out hydroxylation again, the concentration of active oxygen is at 1.0mol/L, and reaction is intermittently being carried out under the stirring condition down at 25 ℃, obtains molar substitution behind the 60min and be 0.8 trihydroxybutyl cellulose ether.
Embodiment 2: the polymerization degree is the plain 10g of 700 pulverizing needle-leaved wood fibre, utilizes 20% the NaOH aqueous solution to carry out the normal temperature alkalization, the 30~40min that under the condition of strong mixing, alkalizes, after through squeezing (press ratio is 2.8), the experienced 20-30min of slaking.In reactor, add toluene 200g, and adding 0.5g Resorcinol, adding the good soda cellulose of oneself alkalization then stirs, carry out twice of vacuum nitrogen filling emptying simultaneously, constantly in 20min, adding 40g epoxy butylene under the stirring condition behind the 5min, temperature is brought up to 60 ℃ of reaction 60min, be warmed up to 85 ℃ of reaction 60~180min again, the PH=7.0 after peroxyacetic acid neutralizes, again repeatedly with pure water mixed solvent washing, drying obtains the faint yellow solid powder, be hydroxyl butylene ether of cellulose, in the peroxyformic acid medium for preparing in advance it carried out hydroxylation again, the concentration of active oxygen is at 1.0mol/L, reaction is being carried out under the stirring condition down intermittently at 25 ℃, obtains molar substitution behind the 60min and be 1.0 trihydroxybutyl cellulose ether.
Embodiment 3: the polymerization degree is at 900 pulverizing gossypin 10g, utilizes 20% the NaOH aqueous solution to carry out the normal temperature alkalization, the 30~80min that under the condition of strong mixing, alkalizes, after through squeezing, press ratio is 2.9, the experienced 20~80min of slaking.In reactor, add normal hexane 200g, and adding 0.3g p-ten.-butylcatechol, adding the good soda cellulose of oneself alkalization then stirs, carry out twice of vacuum nitrogen filling emptying simultaneously, constantly in 20min, adding 30g epoxy butylene under the stirring condition behind the 5min, again temperature is brought up to 60 ℃ of reaction 180min, the PH=7.0 after peroxyacetic acid neutralizes, again repeatedly with pure water mixed solvent washing, drying obtains the faint yellow solid powder, it is hydroxyl butylene ether of cellulose, in the peroxyformic acid medium for preparing in advance, it is carried out hydroxylation again, the concentration of active oxygen is at 1.0mol/L, and reaction is intermittently being carried out under the stirring condition down at 25 ℃, obtains molar substitution behind the 60min and be 0.5 trihydroxybutyl cellulose ether.