Sodium carboxymethyl cellulose, yotchedwa carboxymethyl cellulose (CMC) ndi mtundu wa ether ya polymer fiber ether yokonzedwa ndi kusinthidwa kwa mankhwala a cellulose achilengedwe. Kapangidwe kake ndi gawo la D-glucose kudzera pa β (1→4) Makiyi amalumikizidwa palimodzi.
CMC ndi woyera kapena yamkaka woyera fibrous ufa kapena granules, ndi kachulukidwe wa 0.5-0.7 g/cm3, pafupifupi odorless, zoipa, ndi hygroscopic. Mosavuta omwazikana m'madzi kupanga mandala colloidal njira, insoluble mu organic solvents monga Mowa. PH ya 1% ya madzi amadzimadzi ndi 6.5-8.5, pamene pH> 10 kapena <5, viscosity ya mucilage imachepa kwambiri, ndipo ntchito imakhala yabwino kwambiri pH=7. Wokhazikika pakutentha, kukhuthala kumakwera mofulumira pansi pa 20 ° C, ndipo kumasintha pang'onopang'ono pa 45 ° C. Kutentha kwa nthawi yayitali pamwamba pa 80 ° C kumatha kusokoneza colloid ndikuchepetsa kwambiri kukhuthala ndi magwiridwe antchito. Imasungunuka mosavuta m'madzi ndipo yankho limakhala loonekera; imakhala yokhazikika mumchere wa alkaline, koma imasungunuka mosavuta ikakumana ndi asidi, ndipo imathamanga pamene pH mtengo ndi 2-3, komanso idzachitanso ndi mchere wambiri wazitsulo.
Mapangidwe apangidwe: C6H7(OH)2OCH2COONa Molecular formula: C8H11O5Na
Chochita chachikulu ndichoti: cellulose yachilengedwe imayamba kupangidwa ndi alkalinization reaction ndi NaOH, ndipo powonjezera chloroacetic acid, haidrojeni pagulu la hydroxyl pagawo la shuga imalowa m'malo ndi gulu la carboxymethyl mu chloroacetic acid. Zitha kuwoneka kuchokera pamapangidwe ake kuti pali magulu atatu a hydroxyl pagawo lililonse la shuga, ndiko kuti, C2, C3, ndi C6 hydroxyl magulu. Hydrojeni pa gulu lililonse la hydroxyl imalowetsedwa ndi carboxymethyl, yomwe imatanthauzidwa ngati digiri ya m'malo mwa 3. Mlingo wa kulowetsedwa kwa CMC umakhudza mwachindunji kusungunuka, emulsification, thickening, bata, kukana asidi ndi kukana mchere waCMC .
Ambiri amakhulupirira kuti pamene mlingo wolowa m'malo uli pafupi ndi 0.6-0.7, ntchito ya emulsifying imakhala yabwinoko, ndipo ndi kuwonjezeka kwa mlingo wolowa m'malo, katundu wina amasinthidwa moyenerera. Pamene mlingo wolowa m'malo uli waukulu kuposa 0,8, kukana kwake kwa asidi ndi kukana mchere kumawonjezeka kwambiri. .
Kuphatikiza apo, zatchulidwanso pamwambapa kuti pali magulu atatu a hydroxyl pagawo lililonse, ndiko kuti, magulu achiwiri a hydroxyl a C2 ndi C3 ndi gulu loyambirira la hydroxyl la C6. Mwachidziwitso, ntchito ya gulu loyamba la hydroxyl ndi lalikulu kuposa gulu lachiwiri la hydroxyl, koma malinga ndi zotsatira za isotopic za C, gulu la -OH pa C2 Ndilo acidic kwambiri, makamaka m'malo a alkali amphamvu, ntchito yake. ndi yamphamvu kuposa C3 ndi C6, kotero imakonda kusintha m'malo, kutsatiridwa ndi C6, ndipo C3 ndiyofooka kwambiri.
M'malo mwake, magwiridwe antchito a CMC samangokhudzana ndi kuchuluka kwa kulowetsedwa m'malo, komanso kufananizidwa kwamagulu a carboxymethyl mu molekyulu yonse ya cellulose ndikulowa m'malo mwa magulu a hydroxymethyl mugawo lililonse ndi C2, C3, ndi C6 mu molekyu iliyonse. zokhudzana ndi kufanana. Popeza CMC ndi ma polymerized linear pawiri, ndipo gulu lake la carboxymethyl limakhala ndi m'malo mosiyanasiyana mu molekyulu, mamolekyuwa amakhala ndi magawo osiyanasiyana pomwe yankho lasiyidwa, ndipo kutalika kwa molekyulu yamzere kumakhala kosiyana pakakhala kukameta ubweya mu yankho. . Mzerewu uli ndi chizolowezi chotembenukira kumayendedwe oyenda, ndipo chizoloŵezichi chimakhala champhamvu ndi kuwonjezeka kwa kumeta ubweya mpaka kukhazikika komaliza kukonzedwa. Chikhalidwe ichi cha CMC chimatchedwa pseudoplasticity. Pseudoplasticity ya CMC ndiyothandiza ku homogenization ndi mayendedwe a mapaipi, ndipo sidzalawa kwambiri mkaka wamadzimadzi, womwe umathandizira kutulutsa fungo la mkaka. .
Kuti tigwiritse ntchito zinthu za CMC, tiyenera kumvetsetsa bwino magawo akulu monga kukhazikika, kukhuthala, kukana kwa asidi, komanso kukhuthala. Dziwani momwe timasankhira mankhwala oyenera.
Otsika mamasukidwe akayendedwe mankhwala CMC ndi kukoma mpumulo, otsika mamasukidwe akayendedwe, ndipo pafupifupi kumverera wandiweyani. Amagwiritsidwa ntchito makamaka mu sauces ndi zakumwa zapadera. Zakumwa zam'kamwa zathanzi ndizosankhanso zabwino.
Medium-viscosity CMC mankhwala amagwiritsidwa ntchito makamaka mu zakumwa zolimba, zakumwa wamba mapuloteni ndi timadziti zipatso. Momwe mungasankhire zimadalira zizolowezi za akatswiri. Pakukhazikika kwa zakumwa zamkaka, CMC yathandizira kwambiri.
Zinthu zowoneka bwino za CMC zili ndi malo ogwiritsira ntchito ambiri. Poyerekeza ndi wowuma, guar chingamu, xanthan chingamu ndi zinthu zina, kukhazikika kwa CMC akadali zoonekeratu, makamaka nyama nyama, posungira madzi mwayi CMC ndi zoonekeratu! Pakati pa zokhazikika monga ayisikilimu, CMC ndi chisankho chabwino.
Zizindikiro zazikulu zoyezera mtundu wa CMC ndi digiri ya m'malo (DS) ndi chiyero. Nthawi zambiri, katundu wa CMC ndi wosiyana ngati DS ndi yosiyana; kumtunda kwa mlingo woloweza m'malo, kumapangitsanso kusungunuka kwamphamvu, komanso bwino kuwonekera ndi kukhazikika kwa yankho. Malinga ndi malipoti, kuwonekera kwa CMC ndikwabwinoko pomwe kuchuluka kwa m'malo ndi 0.7-1.2, ndipo kukhuthala kwake kwamadzimadzi ndikokulirapo pomwe pH mtengo ndi 6-9.
Pofuna kuonetsetsa khalidwe lake, kuwonjezera pa kusankha etherification wothandizira, zinthu zina zimene zimakhudza mlingo wa m'malo ndi chiyero ayeneranso kuganizira, monga ubale kuchuluka kwa alkali ndi etherification wothandizira, etherification nthawi, madzi zili mu dongosolo, kutentha, DH mtengo, njira Concentration ndi mchere etc.
Ubwino wa CMC zomalizidwa makamaka zimatengera yankho la mankhwalawo. Ngati yankho la mankhwalawa likuwonekera bwino, pali tinthu tating'ono ta gel, ulusi waulere, ndi mawanga akuda a zonyansa, zimatsimikiziridwa kuti mtundu wa CMC ndi wabwino. Ngati yankho latsala kwa masiku angapo, yankho silikuwoneka. White kapena turbid, koma zomveka bwino, ndicho chinthu chabwino!
Nthawi yotumiza: Dec-14-2022