CELLULOSE -GREEN AGROCHEM

1. Hydroxyethyl cellulose is a natural polymer, each fibrous ring ring contains three hydroxyl groups, the most active hydroxyl reaction, the formation of hydroxyethyl cellulose. The raw cotton linter or refined pulp is soaked in 30% of the liquid base and the press is removed after half an hour. Crushed to alkali water containing 1: 2.8, crushed. Crushed alkali cellulose into the reactor, sealed, vacuum, nitrogen, repeated vacuum nitrogen filling the kettle air replacement. Pressed into the pre-cooling of the ethylene oxide liquid, the reactor jacket into the cooling water, control 25 ℃ reaction 2h, the crude hydroxyethyl cellulose. Crude alcohol with alcohol, listen to polyester, add acetic acid and to pH4-6, plus glyoxal cross-linked aging. Then washed with water, centrifuged dehydrated, dried and ground to obtain hydroxyethylcellulose. Raw material consumption (kg / t) Cotton linter or low pulp 730-780 Liquid base (30%) 2400 Ethylene oxide 900 Alcohol (95%) 4500 Acetic acid 240 Glyoxal (40%) 100-300

2. Immerse the cotton linter or refined cotton pulp in 30% lye. Remove after pressing. Followed by pulverization, followed by reaction with pre-cooled ethylene oxide to produce crude hydroxyethylcellulose. Then washed with alcohol, and acetic acid washed and neutralized. Then add glyoxal cross-linked aging, fast washing with water. Finally by centrifugal dehydration, drying, milling, that was finished.

3. The raw cotton linter soaked in 30% lye, 0.5h after the removal of the press, squeeze to the proportion of alkali water up to 1: 2.8, to crush. Crushed alkali cellulose into the reactor, vacuum, nitrogen replacement kettle air, into the pre-cooling of the ethylene oxide gas, the reactor jacket into the cooling water, control 25 ℃ reaction 2h, was hydroxy Base cellulose crude. Crude alcohol washed, add acetic acid and pH to 4 ~ 6, plus glyoxal cross-linked aging. Then washed with water, centrifuged dehydrated, dried and ground to obtain hydroxyethylcellulose. Per ton of product consumption of cotton pulp 750kg, ethylene oxide 900kg, acetic acid 250kg, ethanol 2600kg, solid base 400kg.

4. Gas phase gas phase method is added during the reaction of additives or thinner, alkali fiber and EO in the gas phase reaction. The process is as follows:

The cotton fiber was immersed in 18.5% NaOH solution, activated, then pressed, crushed and placed in a reactor. The reactor was evacuated by vacuum, nitrogen was added twice, EO was added and reacted at a vacuum degree of 90.64 kPa and 27-32 ° C for 3 to 3.5 hours to obtain product HEC.

5. Liquid phase liquid method is in the presence of diluent etherification reaction. The process is as follows:

The cotton linter is alkalized and pressed, and in the presence of diluent, reacted with EO at 20 ~ 60 ℃ for 1 ~ 3h to obtain crude product HEC. Commonly used diluents are acetone, isopropanol, t-butanol or mixtures thereof. The product remains insoluble in the diluent. Gas phase and liquid phase of the two production processes need to be prepared in advance alkali cellulose, that is, cellulose at about 20 ℃ immersed in 18% NaOH solution for degreasing, etherification reaction, after neutralization, washing, drying, crushing, obtained Final product.

Anti-dispersibility is an important measure of the quality of anti-dispersant. HPMC is a water-soluble polymer compound, also known as water-soluble resin or water-soluble polymer, by increasing the viscosity of the mixed water to increase the consistency of the mixture, is a hydrophilic polymer material, dissolved in water to form a solution Or dispersion. It can be seen that when the dosage of naphthalene superplasticizer is increased, the incorporation of water reducing agent will reduce the anti-dispersibility of fresh cement mortar. This is because the naphthalene superplasticizer is a surfactant. When the water reducing agent is added to the mortar, the water reducing agent is arranged on the surface of the cement particles so that the surface of the cement particles has the same charge. The electric repulsion causes the cement particles to form Of the flocculation structure is broken up, the structure of the water wrapped in the release, will cause a part of the loss of cement. At the same time, it was found that the anti-dispersibility of fresh cement mortar was getting better with the increase of HPMC content.
Strength characteristics of concrete
The HPMC underwater non-dispersible concrete admixture is used in the bridge foundation engineering of the Dandu-line (Dandong-Tonghua) expressway. The design strength grade is C25. The optimum dosage of HPMC is 0.6% of cement, 0.4% of water and cement is 40%, the rate of water is 40%, and the amount of naphthalene superplasticizer is 40% The average strength of the concrete in the air was 42.6 MPa, and the average strength of the underwater pouring concrete was 36.4 MPa underwater drop height of 60 mm. The concrete in the water was molded in the air and the air was molded The intensity ratio of 84.8%, the effect is significant.
(1) The addition of HPMC has obvious retardation effect on the mortar mixture. With the increase of the amount of HPMC, the setting time of mortar is prolonged, and the same amount of HPMC is more The molding time in air is longer. This feature is advantageous for pumping underwater concrete.
(2) mixed with hydroxypropyl methyl cellulose new cement mortar has a good adhesion performance, almost no bleeding phenomenon.
(3) HPMC content and mortar water demand showed a significant increase after the first increase.
(4) the incorporation of water reducing agent to improve the mortar water demand increases, but must be reasonable control of its content, or sometimes the new cement mortar underwater anti-dispersion is reduced.
(5) The cement cement paste injected with HPMC had little difference from the structure of the blank specimen, and the structure and density of the cement paste in the water pouring and the air were not big. Underwater molding 28 d of the specimen slightly crisp. The main reason is that the addition of HPMC, although greatly reduced when the water pouring cement loss and dispersion, but also make the cement stone to reduce the degree of density. In the project to ensure that the water does not disperse the effect of the case, due to minimize the amount of HPMC.
(6) The incorporation of HPMC underwater non-dispersible concrete admixture to control the good content of the strength of the benefit of the pilot project shows that the water forming concrete and air molding strength ratio of 84.8%, the effect is significant.

The base cellulose is first prepared and then reacted with an etherifying agent
And the remaining base, the product is isolated and purified, dried and pulverized to obtain the product.
    In general, when the HPC is prepared by the slurry technique, the alkali cellulose is generally powdered or pulverized
Cotton as raw material, dispersed in organic thinner, and NaOH aqueous solution at room temperature and obtained. Commonly used
The organic diluent is alcohol (such as isopropyl alcohol, tert-butanol), acetone, also useful etherification agent propylene oxide. The composition of alkali cellulose is essential for the preparation of products with good water solubility and uniformity.
The composition ratio of the ratio of cellulose to NaOH is 1: (0.2 to 0.4); the mass ratio of the aqueous paste to the cellulose raw material
Ratio of 1: (0.15 to 0.30), the water content should be as low as possible to reduce side effects. Diluent and cellulose quality
Ratio, depending on the reaction equipment in the 3 to 15: 1 between the changes.
    The organic diluent used in the etherification reaction may be the IPA, TBA, etc. used for the alkalization, and the organic diluent
With non-polar such as hexane, toluene or the like. It is generally believed that the reaction rate below 50 ℃ is very slow
80 ℃ above the side reaction is very fast, so the reaction temperature to 55 ~ 85 ℃ is appropriate, the reaction time of 5 ~ lOh.
    HPC purification is much simpler than the HEC, only to neutralize the separation of the crude into more than 85 ℃
Hot water repeatedly rinse, you can water-soluble salts, propylene glycol and other debris removed to achieve the purpose of purification.
    The low-substituted HPC can be prepared by a conventional slurry process. While the high degree of substitution HPC production with two
Step to avoid excessive expansion during alkalization, help to improve the solubility, propylene oxide utilization and products
purity. The inert solvent in the alkalization process may be an alcohol of 3 to 5 carbon atoms (e.g., isopropanol, pentanol, tert
Butanol), dioxane, acetone and propylene oxide, and the etherification process of non-solvent can be used aliphatic and aromatic
Perfume, and alkyl ethers.
    The resulting HPC can be washed with hot water (because it is insoluble above 45 ° C), well-dispensed HPC
The best part of the product can also be treated with glyoxal and then dried and packaged. Many patents have been reported about the deal
The method of the improvement comprises the drying of the alkali cellulose in the intermediate step, the infiltration of the alkali cellulose to reduce
NaOH concentration, in the process of hydroxypropylation with amine catalyst.
    Here are two HPC production processes.
    (1) 100 parts of wood pulp (100 mesh), 50 to 100 parts of IPA and 280 parts of PO were added to a kneader
, In the Nz atmosphere stirring 20min. The temperature was then raised to 60 ° C and reacted at this temperature for 5 h, raising the temperature
Reaction to 70 ° C th. The reaction mixture was separated and the crude product was allowed to neutralize, washed with hot water at about 90 ° C,
The purified product was centrifuged and centrifuged to give HPC. The MS was 3.6, the etherification efficiency was 46. 0%
Dissolved in water and ethanol, 2% solution of the light transmittance of 95% or more. If the raw material pulp fineness is not reached
100 or more, or increase the amount of 1PA and PO, will reduce the MS and etherification efficiency.
    (2) 1 part of powdered pulp was added to a mixture consisting of 13 parts of TBA, 1.4 parts of water and 0.1 part of NaOH
And the mixture was stirred at 25-40 ° C to prepare an alkali fiber pulp. Centrifuge the filter to remove most of the
TBA after the press ratio of 1.52, containing fiber turbidity 61.3%, NaOH 6.3%, water 15. 4% and
TBA17. O% of the alkali cellulose. 6.5 parts of this alkali cellulose was added to the etherification reactor and replaced with nitrogen
After the addition of 28 parts of hexane and 6.4 parts of PO, stirring, heating, in vain 80 ℃ reaction 3h. At this point has been generated
HPC has a MS of 2.3. The reaction mixture was cooled to 50 ° C, 2 parts of water and 3.6 parts of PO were added and the temperature was warmed
Degrees up to 80 ℃ reaction 2h or so. Neutralize, remove the crude product and wash with hot water, dry, crushed to produce
Product HPC. The MS is 3.5, the etherification efficiency is 50% in water, methanol, ethanol and IPA, TBA
Dissolved, 2% solution of light transmittance of 93% or more.
    Theoretical analysis and practical experience have shown that the full pulverization of cellulose raw materials is necessary. Can be crushed
To reduce the crystallinity of the cellulose, to improve the accessibility of the reaction, but also easy to make it more evenly dispersed in the inert media

A drilling-fluid additive used primarily for fluid-loss control, manufactured by reacting natural cellulose with monochloroacetic acid and sodium hydroxide[NaOH] to form CMC sodium salt. Up to 20 wt % of CMC may be NaCl, a by-product of manufacture, but purified grades of CMC contain only small amounts of NaCl. To make CMC, OH groups on the glucose rings of cellulose are ether-linked to carboxymethyl (-OCH₂-COO^–) groups. (Note the negative charge.) Each glucose ring has three OH groups capable of reaction, degree-of-substitution = 3. Degree of substitution determines watersolubility and negativity of the polymer, which influences a CMC’s effectiveness as a mud additive. Drilling grade CMCs used in muds typically have degree-of-substitution around 0.80 to 0.96. Carboxymethylcellulose is commonly supplied either as low-viscosity (“CMC-Lo Vis”) or high-viscosity (“CMC-Hi Vis”) grades, both of which have API specifications. The viscosity depends largely on the molecular weight of the starting cellulose material.

1.Adding the Carboxymethyl cellulose into the slurry, it can help slurry to form a thin, strong and ow permeability filter cake in the well, to reduce water loss.
2. Adding the Carboxymethyl cellulose into the slurry, it can easy to release the gas in the slurry, and keep the debris in the pit quickly.
3.The drilling slurry also have existence of time same as other suspension. , after adding CMC to make it stable and to extend the lifespan. 4. The slurry which containing Carboxymethyl cellulose will little affected by the mold, so there are no need preservatives additive and maintaining a high PH value
5. Carboxymethyl cellulose can anti-pollution of a variety of soluble salts in the pit as flushing fluid drilling.
6. The slurry which containing Carboxymethyl cellulose has very good stability, it still reduce water loss even the temperature is above 150 ℃. To choose which kinds of Carboxymethyl cellulose can use in oil drilling, should be based on the slurry type, the region, the depth and other different conditions. High viscosity, high degree of substitution of Carboxymethyl cellulose should use in the low slurry density. for density of the slurry should use low viscosity, high degree of substitution of Carboxymethyl cellulose.

1.act as the binder and play a bonding role. It can increase the strength of raw glaze, reduce the
drying shrinkage of glaze, make the green body and the glaze firmly combined and not easy to fall
off, be easy for process operation, and prevent such defects as rolling and missing of glaze. While
playing the role of suspension, it makes the ceramic slurry suspended and prevents precipitation.
2.play its role of water retention, so that the glaze slurry has a certain water retention and the
glaze layer are uniform drying, forming a flat, dense glazed surface and the glazed surface is flat
and smooth after firing.
3.use the deagglomeration effects of CMC (of medium and low viscosity) to improve the
liquidity of glaze slurry and facilitate the spraying operation of glaze. To achieve the above
purposes, it is very important to give full play to the effects of CMC, grasp the properties of CMC
and the effects of temperature and time on it, and properly select and apply CMC.