Phunzirani pakusintha kwa cellulose etherification ndikugwiritsa ntchito phala losindikiza la utoto

Kuyambira kukhazikitsidwa kwa utoto wokhazikika m'zaka zapitazi, sodium alginate (SA) yakhala yoyambira pakusindikiza utoto pansalu za thonje.

phala. Komabe, ndi mosalekeza kusintha kwa anthu zofunika kusindikiza kwenikweni, sodium alginate monga kusindikiza phala si kugonjetsedwa ndi asidi amphamvu ndi zamchere.

Ndipo kukhuthala kwapangidwe kumakhala kochepa, kotero ntchito yake yosindikizira yozungulira (yophwanyika) imakhala yochepa pamlingo wina;

Mtengo wa sodium alginate ukukweranso, kotero anthu ayamba kufufuza njira zina, cellulose ether ndi imodzi mwa zofunika kwambiri.

okoma mtima. Koma pakadali pano chinthu chachikulu chomwe chimagwiritsidwa ntchito popanga cellulose ether ndi thonje, kutulutsa kwake kukutsika, ndipo mtengo ukukulanso.

Kuphatikiza apo, mankhwala omwe amagwiritsidwa ntchito kwambiri monga chloroacetic acid (poizoni kwambiri) ndi ethylene oxide (carcinogenic) nawonso amawononga kwambiri thupi la munthu komanso chilengedwe.

Poganizira izi, mu pepalali, ether ya cellulose idachotsedwa ku zinyalala za zomera, ndipo sodium chloroacetate ndi 2-chloroethanol amagwiritsidwa ntchito ngati etherifying agents pokonzekera carboxylate.

Mitundu itatu ya ulusi: methyl cellulose (CMC), hydroxyethyl cellulose (HEC) ndi hydroxyethyl carboxymethyl cellulose (HECMC)

atatuma cellulose ethersndi SA zidagwiritsidwa ntchito posindikiza utoto wa thonje, ndipo zotsatira zake zosindikiza zidafaniziridwa ndikuphunziridwa.

zipatso. Zomwe zili mu kafukufukuyu zimagawidwa m'magawo atatu:

(1) Chotsani cellulose ku zinyalala za zomera. Kupyolera mu mankhwala a zinyalala zisanu za zomera (udzu wa mpunga, mankhusu a mpunga, udzu wa tirigu, utuchi wa paini

ndi bagasse) pofuna kudziwa ndi kusanthula zigawo zikuluzikulu (chinyezi, phulusa, lignin, cellulose ndi hemicellulose), osankhidwa.

Zida zitatu zoyimira mbewu (utuchi wa paini, udzu wa tirigu ndi bagasse) zimagwiritsidwa ntchito potulutsa mapadi, ndipo cellulose amachotsedwa.

Njirayi idakonzedwa bwino; pansi pamikhalidwe yokonzedwa bwino, magawo a pine cellulose, udzu wa tirigu wa cellulose ndi bagasse cellulose adapezedwa.

Ukhondo uli pamwamba pa 90%, ndipo zokolola zili pamwamba pa 40%; zitha kuwoneka pakuwunika kwa ma infrared spectrum ndi mayamwidwe a ultraviolet kuti zonyansa

Lignin ndi hemicellulose zimachotsedwa kwenikweni, ndipo cellulose yomwe yapezeka imakhala ndi chiyero chachikulu; zitha kuwoneka kuchokera pakuwunika kwa diffraction ya X-ray kuti ndizofanana ndi zopangira zopangira.

Poyerekeza, crystallinity wachibale wa mankhwala anapeza bwino kwambiri.

(2) Kukonzekera ndi mawonekedwe a cellulose ethers. Pogwiritsa ntchito mapanelo a matabwa a pine otengedwa mu utuchi wa paini ngati zopangira, kuyesa kwa chinthu chimodzi kunachitika.

Njira yowonjezera ya alkali decrystallization pretreatment process ya pine cellulose idakonzedwa bwino; ndi kupanga zoyesera za orthogonal ndi kuyesa kwa chinthu chimodzi, the

Njira zokonzekera CMC, HEC ndi HECMC kuchokera kumitengo ya pine alkali cellulose zidakonzedwa motsatana;

CMC yokhala ndi DS mpaka 1.237, HEC yokhala ndi MS mpaka 1.657, ndipo HECMC yokhala ndi DS ya 0.869 idapezedwa. Malinga ndi kusanthula kwa FTIR ndi H-NMR, magulu a ether ofanana adalowetsedwa muzinthu zitatu za cellulose etherification;

Mitundu ya kristalo ya plain ethers CMC, HEC ndi HEECMC zonse zinasintha kukhala mtundu wa cellulose II, ndipo crystallinity inachepa kwambiri.

(3) Kugwiritsa ntchito phala la cellulose ether. Mitundu itatu ya ethers ya cellulose yokonzedwa pansi pamikhalidwe yabwino kwambiri idagwiritsidwa ntchito pansalu ya thonje

Amasindikizidwa ndi utoto wokhazikika komanso poyerekeza ndi sodium alginate. Kafukufukuyu adapeza kuti SA, CMC, HEC ndi HECMC zinayi zoyambitsa

Ma phala onse ndi madzi a pseudoplastic, ndipo pseudoplasticity ya ma cellulose ethers atatu ndi abwino kuposa a SA; dongosolo la phala mapangidwe mitengo ya phala anayi

Ndi: SA > CMC > HECMC > HEC. Pankhani ya kusindikiza, CMC yowoneka bwino yokolola ndi kulowa, kusindikiza dzanja

Sensitivity, kusindikiza mtundu mofulumira, etc. ndi ofanana ndi SA, ndi depaste mlingo wa CMC ndi bwino kuposa SA;

SA ndi yofanana, koma HEC yowoneka bwino ya mtundu, permeability ndi kupukuta mofulumira ndizochepa kuposa SA; HECMC yosindikiza imamva, kukana kukana

Kuthamanga kwamtundu kupukuta ndi kofanana ndi SA, ndipo kuchuluka kwa phala ndipamwamba kuposa SA, koma zokolola zowoneka bwino zamtundu ndi kukhazikika kosungirako kwa HEECMC ndizotsika kuposa SA.

Mawu ofunikira: zinyalala za mbewu; cellulose; cellulose ether; kusintha kwa etherification; zotakataka utoto kusindikiza;