Cellulose ether ndi chinthu chofunika kwambiri chomangira, chomwe chimagwiritsidwa ntchito kwambiri pomanga matope, putty ufa, zokutira ndi zinthu zina kuti zipititse patsogolo mphamvu zakuthupi ndi zomangamanga. Zigawo zazikulu za cellulose ether zimaphatikizapo kapangidwe ka cellulose ndi zolowa m'malo zomwe zimayambitsidwa ndi kusintha kwa mankhwala, zomwe zimapatsa kusungunuka kwapadera, kukhuthala, kusunga madzi ndi rheological katundu.
1. Mapangidwe a cellulose
Ma cellulose ndi amodzi mwa ma polysaccharides omwe amapezeka kwambiri m'chilengedwe, makamaka omwe amachokera ku ulusi wazomera. Ndilo gawo lalikulu la cellulose ether ndipo limatsimikizira kapangidwe kake ndi katundu wake. Ma cellulose amapangidwa ndi mayunitsi a shuga olumikizidwa ndi β-1,4-glycosidic bond kuti apange unyolo wautali. Izi liniya dongosolo amapereka mapadi mphamvu mkulu ndi mkulu maselo kulemera, koma solubility ake m'madzi ndi osauka. Pofuna kukonza kusungunuka kwamadzi kwa cellulose ndikutengera zosowa za zida zomangira, cellulose iyenera kusinthidwa ndi mankhwala.
2. Zolowa m'malo-zigawo zazikulu za kachitidwe ka etherification
Makhalidwe apadera a cellulose ether amapindula makamaka ndi zomwe zimayambitsidwa ndi etherification reaction pakati pa gulu la hydroxyl (-OH) la cellulose ndi ether mankhwala. Zomwe zimagwiritsidwa ntchito ndi methoxy (-OCH₃), ethoxy (-OC₂H₅) ndi hydroxypropyl (-CH₂CHOHCH₃). Kuyamba kwa zinthu izi kumasintha kusungunuka, kukhuthala ndi kusunga madzi kwa cellulose. Malinga ndi zolowa m'malo osiyanasiyana, ma cellulose ether amatha kugawidwa kukhala methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl methyl cellulose (HPMC) ndi mitundu ina.
Methyl cellulose (MC): Methyl cellulose amapangidwa poyambitsa ma methyl substituents (-OCH₃) m'magulu a hydroxyl mu molekyulu ya cellulose. Ether ya cellulose iyi imakhala ndi kusungunuka kwamadzi bwino komanso kukhuthala ndipo imagwiritsidwa ntchito kwambiri mumatope owuma, zomatira ndi zokutira. MC ili ndi madzi osungira bwino kwambiri ndipo imathandizira kuchepetsa kutaya kwa madzi muzomangamanga, kuonetsetsa kumamatira ndi mphamvu ya matope ndi putty powder.
Hydroxyethyl cellulose (HEC): Hydroxyethyl cellulose imapangidwa poyambitsa hydroxyethyl substituents (-OC₂H₅), yomwe imapangitsa kuti ikhale yosungunuka m'madzi komanso yosamva mchere. HEC imagwiritsidwa ntchito kwambiri popaka utoto wamadzi, utoto wa latex ndi zowonjezera zomanga. Ili ndi zokhuthala bwino komanso zopanga mafilimu ndipo zimatha kupititsa patsogolo ntchito yomanga ya zida.
Hydroxypropyl methylcellulose (HPMC): Hydroxypropyl methylcellulose imapangidwa ndi kuyambitsa munthawi yomweyo kwa hydroxypropyl (-CH₂CHOHCH₃) ndi methyl substituents. Mtundu uwu wa ether wa cellulose umawonetsa kusungidwa bwino kwa madzi, kutsekemera komanso kugwira ntchito kwa zinthu zomangira monga matope owuma, zomatira matailosi, ndi makina otsekereza khoma. HPMC ilinso ndi kukana kutentha kwabwino komanso kukana chisanu, kotero imatha kusintha bwino magwiridwe antchito azinthu zomangira pansi panyengo yanyengo.
3. Kusungunuka kwamadzi ndi kukhuthala
Kusungunuka m'madzi kwa cellulose ether kumatengera mtundu ndi kuchuluka kwa m'malo mwake (mwachitsanzo, kuchuluka kwa magulu a hydroxyl osinthidwa pagawo lililonse la shuga). Mlingo woyenera wolowa m'malo umathandizira kuti ma cellulose apange njira yofananira m'madzi, zomwe zimapangitsa kuti zinthuzo zikhale zabwino kwambiri. M'zinthu zomangira, ma cellulose ethers monga thickeners amatha kuwonjezera kukhuthala kwa matope, kuteteza kusakanikirana ndi kulekanitsa zipangizo, motero kupititsa patsogolo ntchito yomanga.
4. Kusunga madzi
Kusungidwa kwamadzi kwa cellulose ether ndikofunikira kuti zida zomangira zikhale zabwino. Muzinthu monga matope ndi ufa wa putty, cellulose ether imatha kupanga filimu yamadzi wandiweyani pamwamba pa zinthuzo kuti madzi asatuluke mwachangu, potero amakulitsa nthawi yotseguka komanso kugwira ntchito kwa zinthuzo. Izi zimagwira ntchito yofunika kwambiri pakukulitsa mphamvu yolumikizana komanso kupewa kusweka.
5. Rheology ndi ntchito yomanga
Kuwonjezera pa cellulose ether kwambiri bwino rheological katundu wa zomangira, ndiko kuti, otaya ndi mapindikidwe khalidwe la zipangizo pansi mphamvu kunja. Iwo akhoza kusintha kasungidwe madzi ndi lubricity a matope, kuonjezera pumpability ndi chosavuta kumanga zipangizo. Pomanga monga kupopera mbewu mankhwalawa, kukanda ndi kumanga, cellulose ether imathandizira kuchepetsa kukana ndikuwongolera magwiridwe antchito, ndikuwonetsetsa kuti zokutira yunifolomu popanda kugwa.
6. Kugwirizana ndi kuteteza chilengedwe
Cellulose ether imagwirizana bwino ndi zipangizo zosiyanasiyana zomangira, kuphatikizapo simenti, gypsum, laimu, ndi zina. Kuonjezera apo, cellulose ether ndi zowonjezera zobiriwira komanso zachilengedwe, zomwe zimachokera makamaka ku ulusi wa zomera zachilengedwe, zimakhala zopanda vuto kwa chilengedwe, ndipo zimakwaniritsa zofunikira za chitetezo cha chilengedwe cha zipangizo zamakono zamakono.
7. Zosakaniza zina zosinthidwa
Pofuna kupititsa patsogolo ntchito ya cellulose ether, zosakaniza zina zosinthidwa zitha kuyambitsidwa pakupanga kwenikweni. Mwachitsanzo, opanga ena amawonjezera kukana kwamadzi ndi kukana kwanyengo kwa cellulose ether pophatikiza ndi silicone, parafini ndi zinthu zina. Kuphatikizika kwa zinthu zosinthidwazi nthawi zambiri kumakwaniritsa zofunikira zenizeni zogwiritsira ntchito, monga kukulitsa zinthu zotsutsana ndi permeability ndi kulimba kwa zokutira kunja kwa khoma kapena matope osalowa madzi.
Monga gawo lofunikira muzomangira, cellulose ether imakhala ndi zinthu zambiri, kuphatikiza kukhuthala, kusunga madzi, komanso kuwongolera bwino kwa ma rheological. Zigawo zake zazikulu ndi kapangidwe ka cellulose ndi zolowa m'malo zomwe zimayambitsidwa ndi etherification reaction. Mitundu yosiyanasiyana ya ma cellulose ethers imakhala ndi ntchito zosiyanasiyana komanso magwiridwe antchito pazomangira chifukwa cha kusiyana kwawo. Ma cellulose ethers sangangowonjezera ntchito yomanga, komanso kupititsa patsogolo moyo wabwino wanyumba ndi ntchito zonse. Chifukwa chake, ma cellulose ethers ali ndi mwayi wogwiritsa ntchito kwambiri pazomangira zamakono.
Nthawi yotumiza: Sep-18-2024