Essay Example on Methylcellulose Production in Industries

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Methylcellulose production in industries was done under high pressure by methylating alkali cellulose with chloromethane In the mercerization, the quantity of aqueous sodium hydroxide NaOH used was between 35 and 60 The ratio of molar fraction of NaOH to anhydrous glucose unit must be 3 4 to get water soluble ethers with degree of substitution between 1 4 and 2 0 The viscosity of alkali cellulose was familiar with or without catalysis Excess of chloromethane depends on the amount of alkali used By product of methanol and dimethyl ether is formed when chloromethane is reacting with water Alkali can be removed from crude methylcellulose by the process of acid neutralization Methylcellulose can be manufactured under mild pressure in a batch reactor with gaseous chloromethane Brandt 1986 Replace of hydrogen with methyl group by Alkali celluloses with the chloromethane is done at 60 100ºC for several hours During this process a few reagents evaporate with unpredictable by products which are isolated Brandt 1986 Methylcellulose can also be manufactured by one another methylation method under higher pressure in a constant reactor with liquid chloromethane Typically methylation was obtained in a reaction time with a reduction of 1 hour with or without an inert organic liquid

Contents of this process are slurrying the alkali cellulose under pressure in excessive chloromethane The slurry is then passed through a partially heated reaction tube Evaporation is done of volatile byproducts and excessive chloromethane to separate the crude methylcellulose by filtration method Brandt 1986 Investigated techniques enhance effectiveness of methylation by the option of slurry solvents the steady addition of reagents and temperature planned reaction steps etc Sodium chloride and other non-volatile byproducts can be detached by washing with hot water above the gelation temperature of the methylcellulose After that the product made by this method is dried and ground in usual equipment Brandt 1986 There were one another technique to organized Methylcellulose from both wood and annual plants developed by Ye and Farriol and method is named as facile novel methylation method using iodomethane to prepare the product Ye and Farriol 2005a Methylcellulose has a basic repeating structure of anhydrous glucose units and its polymeric strength similar to celluloses and natural carbohydrates

Mercerization of dissolving pulp was done with a concentrated NaOH solution which leads to bloating of cellulose to produce the alkali cellulose to degrade and it decreases the degree of crystallinity Nucleophilic substitution was carried out of the reaction of alkali cellulose and methyl chloride through the interaction of the oxonium sodium hydroxide complexes on this easy to get to hydroxyl of the anhydrous glucose unit Krassig 1993 As cotton has a Degree of Polymerization as high 10 000mPas so methylcellulose of viscosity higher than 50000 mPas in 2 aqueous solutions at ambient temperature from cotton linters Brandt 1986 Methylcellulose of lower viscosities is produced from sulfite chemically treated wood pulps The pulp for the production of methylcellulose was needed as almost free of lignin highly purified and high alpha cellulose content Brandt 1986 By choosing the raw materials cautiously and process parameters the molecular mass of methylcellulose needs to be kept constant within a particular range Krassig 1993 Methylcellulose was widely used in food and pharmaceutical industries for the reason that of its properties like tremendous light sensitive emulsion capacity lipid obstruction function and low oxygen and humidity transmission rate Debeaufort et al 1998 Liang et al 2004, In addition, it has some additional property as thickener protective glue auxiliary emulsification agent binder or film coating forming agent for different quantity forms which accounts for its extensive purpose in pharmaceutical fields Liang et al 2004 Kokubo et al 1998

Another important property of sol gel transformation has been oppressed to intend diverse during the gelling systems It was able to be used as film forming agent and gel due to its water solubility The study was completed to change the thermal gelation temperature of methylcellulose from 68ºC to normal body temperature throughout the reaction gelling of the fluid small dissolvable medicated solid Pasztor et al 2011 Bain et al urbanized of eye formulations by using an ion susceptible polymer methylcellulose and polyethylene glycol as a viscosity modifying agent Sodium tartrate and sodium citrate were the two dissimilar salts which were utilized to reduce the gelation temperature close to the human being body temperature On incorporation of polymeric excipient such as polyethylene glycol the release of drug was absolute from 6 hours to 9 hours and it was more profoundly due to sodium citrate the whole process of drug release time was perhaps due to change in morphology of gel structure from unoccupied fibrous to unified microporous structure thus improving patient compliance Baina et al 2013 Kim et al was prepared methylcellulose on the bases of thermo reversible gel pluronic micelle combination system for local and sustained delivery of docetaxel Kim et al 2012 Moreover the addition of methylcellulose to N isopropylacrylamide polymers was helpful in increasing the mechanical capacity of hydrogel without any type of syneresis Liu et al 2004 Methylcellulose was urbanized by Tate et al for the earliest time as a tissue engineering scaffold which can be used in the treatment of injured brain Another researches also proved that rat’s brain methylcellulose was still remained for two weeks even after post injection Tate et al 2001 The viscosity of methylcellulose is the most significant feature It is strongly depends upon the various properties like the concentration of solution degree of substitution molecular mass the temperature and the sharing of methoxyl faction on the glucose unit The viscosities of methylcellulose are stable having the pH range between 2 to 12 Brandt 1986 Donges 1990 The emulsification of Olive peanut and mineral oils is done with methylcellulose with low grades of viscosity Methylcellulose is also used as a suspending or coagulating agent for the orally liquids Wojdak 1991 Dalal et al 1991

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