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Studies On The Preparation Of Cross-linked Carboxylmethyl Corn Starch(CCMS) By Microwave Solide-state Method And Its Properties And Application

Posted on:2010-10-19Degree:MasterType:Thesis
Country:ChinaCandidate:Y F ZhangFull Text:PDF
GTID:2121360275952767Subject:Agricultural Products Processing and Storage
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With corn starch as raw materials,cross-linked carboxymethyl starch as rapid tablets disintegrant (CCMS) was prepared by a double modified method of cross-linking and etherification,with the technology of microwave solid-state method.Cross-linked carboxymethyl starch's properties, structures and applications in medicinal use were also investigated in this paper.By singe factor experiments,the effects of the varieties of factors on the degree of substitute (DS) of CMS were studied,including the amount of sodium hydroxide,the amount of chloroactic acid,basification temperature,basification time,etherification temperature and the etherification time and so on.Based on this,by using quadratic general rotary experiment design,the optimum technology parameters were confirmed as follows:the the molar ratio of NaOH/CH2ClCOOH 3.2, etherify temperature 90℃,11.36 min for etherify time,basification temperature 40℃,45min for basification time,100W for microwave power.When the molar ratio of CH2ClCOOH/starch was 0.4, the degree of substitution was up to 0.35.The properties of samples were also tested,such as the effects of pH value,shear force and temperature on the solution viscosity of CMS and CCMS,and the pasting property of freeze-thaw stability and the clarity were also involved in this paper.Based on the properties studies of CCMS above,some clues could be found for its application.The structures of samples were analysed,too.Infrared spectroscopy detection indicated that carboxyl group had been introduced into starch molecules,which showed that it was the target product.The SEM showed that the surface of the starch granules of CCMS was rougher than the native starch,and there were some minute holes on its surface.The observation of Polarized light microscopy showed that the polarizing cross intensity of CCMS was weaker than the native starch, which indicated that its crystal section had been involved in the modified reaction partially. TGA-DTA test showed that the heat resistance of CCMS was poorer than the native starch and CMS, but its thermal stability was the best among the samples.DSC analysis showed that the gelatinization temperature of CCMS was lower,compared to the native starch and CMS.X-ray diffraction showed that the crystal structure of CCMS was significantly damaged,and the X-ray diffraction intensity of CMS has weakened,which meant that the modifying occurred not only in the amorphous region but also in the crystalline region of the starch granule.The disintegrative property of samples as rapid tablets disintegrant was investigated finally.The results showed its rapidly swelling in cold water,and could be used as tablets disintegrant.The quality test results of the CMS and CCMS was accord with Chinese Pharmacopoeia standards of CMS(2005 EDITION).Compared with disintegrants sample domestically prepared with potato starch,it could be found that the disintegration time of CCMS was close to or even better,but poorer on the CMS.
Keywords/Search Tags:carboxymethyl starch, cross-linked carboxymethyl starch, rapid tablets disintegrant, properties, structure
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