Kukonzekera kwa carboxymethyl cellulose

Carboxymethyl cellulose (CMC)ndi polima wosungunuka m'madzi wosiyanasiyana wochokera ku cellulose, womwe ndi polysaccharide yachilengedwe yomwe imapezeka m'makoma a maselo a zomera. CMC imapezeka kwambiri m'mafakitale osiyanasiyana kuphatikizapo chakudya, mankhwala, zodzoladzola, nsalu, mapepala, ndi zina zambiri chifukwa cha makhalidwe ake apadera monga kukhuthala, kukhazikika, kumangirira, kupanga filimu, ndi kusunga madzi. Kukonzekera kwa CMC kumaphatikizapo masitepe angapo kuyambira pa kuchotsa cellulose kuchokera kuzinthu zachilengedwe kutsatiridwa ndi kusintha kwake kuti akhazikitse magulu a carboxymethyl.

1. Kutulutsa Cellulose:
Gawo loyamba pokonzekera CMC ndi kuchotsa cellulose kuchokera kuzinthu zachilengedwe monga pulp yamatabwa, thonje, kapena ulusi wina wa zomera. Cellulose nthawi zambiri imapezeka kudzera m'njira zosiyanasiyana kuphatikizapo pulping, bleaching, ndi kuyeretsa. Mwachitsanzo, pulp yamatabwa ingapezeke pogwiritsa ntchito njira zamakina kapena mankhwala zotsukira kutsatiridwa ndi bleaching ndi chlorine kapena hydrogen peroxide kuti muchotse zinyalala ndi lignin.

2. Kuyambitsa kwa Cellulose:
Cellulose ikachotsedwa, iyenera kuyatsidwa kuti ithandize kuyambitsa magulu a carboxymethyl. Kuyatsidwa nthawi zambiri kumachitika pochiza cellulose ndi alkali monga sodium hydroxide (NaOH) kapena sodium carbonate (Na2CO3) pansi pa kutentha ndi kupanikizika kolamulidwa. Chithandizo cha alkali chimakulitsa ulusi wa cellulose ndikuwonjezera reactivity yawo mwa kuswa ma hydrogen bonds amkati ndi pakati pa mamolekyulu.

3. Kachitidwe ka Carboxymethylation:
Maselo oyambitsidwa amayikidwa mu carboxymethylation reaction pomwe magulu a carboxymethyl (-CH2COOH) amalowetsedwa pamagulu a hydroxyl a unyolo wa cellulose. Izi zimachitika nthawi zambiri poyambitsa cellulose ndi sodium monochloroacetate (SMCA) pamaso pa chothandizira cha alkaline monga sodium hydroxide (NaOH). Zomwe zimachitikazi zitha kufotokozedwa motere:

Selulosi + Chloroacetic Acid → Carboxymethyl Selulosi + NaCl

Mikhalidwe ya reaction kuphatikizapo kutentha, nthawi ya reaction, kuchuluka kwa ma reagents, ndi pH zimayendetsedwa mosamala kuti zitsimikizire kuti pali zokolola zambiri komanso mulingo woyenera wa substitution (DS) womwe umatanthauza kuchuluka kwa magulu a carboxymethyl omwe amaperekedwa pa unit iliyonse ya shuga ya cellulose chain.

4. Kusalowerera ndi Kusamba:
Pambuyo pa kachitidwe ka carboxymethylation, carboxymethyl cellulose yomwe imabwera imachotsedwa kuti ichotse alkali yochulukirapo ndi chloroacetic acid yosakhudzidwa. Izi nthawi zambiri zimachitika potsuka mankhwalawa ndi madzi kapena yankho la asidi wochepetsedwa kenako ndikusefa kuti mulekanitse CMC yolimba ndi chisakanizo cha reaction.

5. Kuyeretsa:
CMC yoyeretsedwayo imatsukidwa ndi madzi kangapo kuti ichotse zinthu zodetsa monga mchere, zinthu zosakhudzidwa, ndi zinthu zina. Kusefa kapena kutsekereza madzi kungagwiritsidwe ntchito kuti CMC yoyeretsedwayo ilekanitsidwe ndi madzi otsukira.

6. Kuumitsa:
Pomaliza, carboxymethyl cellulose yoyeretsedwa imaumitsidwa kuti ichotse chinyezi chotsalira ndikupeza chinthu chomwe mukufuna mu mawonekedwe a ufa wouma kapena granules. Kuumitsa kumatha kuchitika pogwiritsa ntchito njira zosiyanasiyana monga kuumitsa mpweya, kuumitsa vacuum, kapena kuumitsa popopera kutengera mawonekedwe omwe mukufuna a chinthu chomaliza.

7. Kufotokozera Makhalidwe ndi Kuwongolera Ubwino:
ZoumaCMCChogulitsachi chimayesedwa njira zosiyanasiyana zodziwira zinthu monga Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), ndi muyeso wa viscosity kuti zitsimikizire kapangidwe kake ka mankhwala, mlingo wa kusintha, kulemera kwa mamolekyulu, ndi kuyera. Mayeso owongolera khalidwe amachitidwanso kuti atsimikizire kuti chinthucho chikukwaniritsa zofunikira pa ntchito zake zomwe akufuna.

Kukonzekera kwa carboxymethyl cellulose kumaphatikizapo njira zingapo kuphatikizapo kuchotsa cellulose kuchokera kuzinthu zachilengedwe, kuyambitsa, carboxymethylation reaction, neutralization, cleansing, drying, and specification. Gawo lililonse limafuna kuwongolera mosamala momwe zinthu zimachitikira komanso magawo ake kuti akwaniritse zokolola zambiri, mlingo wofunikira wosinthira, komanso mtundu wa chinthu chomaliza. CMC ndi polima yomwe imagwiritsidwa ntchito kwambiri yokhala ndi ntchito zosiyanasiyana chifukwa cha mawonekedwe ake apadera komanso kusinthasintha kwake.