Cellulose ether ipolymer yakagadzirwa kubva kucellulose yechisikigo kuburikidza nekuchinja kwemakemikari. Cellulose ether inobva kucellulose yechisikigo. Kugadzirwa kwecellulose ether kwakasiyana nemapolymer ekugadzira. Chinhu chayo chikuru icellulose, musanganiswa wepolymer wechisikigo. Nekuda kwehunhu hwechimiro checellulose yechisikigo, cellulose pachayo haina kugona kuita ne etherification agents. Zvisinei, mushure mekurapwa kwemushonga wekuzvimba, hydrogen bonds yakasimba pakati pemaketani emamorekuru nemaketani inoparadzwa, uye kusunungurwa kwehydroxyl group kunova reactive alkali cellulose. Wana cellulose ether.
Muhari yakasanganiswa yakagadzirwa, huwandu hwekuwedzera kwe cellulose ether hwakaderera zvikuru, asi hunogona kuvandudza mashandiro ehari yakanyorova, uye chinhu chikuru chinokanganisa mashandiro ehari. Kusarudzwa kwakanaka kwe ether dze cellulose dzemhando dzakasiyana, viscosities dzakasiyana, saizi dzakasiyana dzezvimedu, madhigirii akasiyana ekusimba uye huwandu hwakawedzerwa zvichave nemhedzisiro yakanaka pakuvandudzwa kwebasa rehari yakapfava. Parizvino, mahari mazhinji ekugadzira nekuisa plaster haana mashandiro akanaka ekuchengetedza mvura, uye mvura inotsvedza inoparadzana mushure memaminitsi mashoma ekumira.
Kuchengetwa kwemvura ibasa rakakosha remethyl cellulose ether, uye ibasa iro vagadziri vemadhaka emumba vanosanganisa dry-mix, kunyanya avo vari kumaodzanyemba kwenzvimbo dzine tembiricha yakakwira, vanoteerera. Zvinhu zvinokanganisa kuchengetedzwa kwemvura kwedhaka remusanganiswa wakaoma zvinosanganisira huwandu hweMC yakawedzerwa, viscosity yeMC, kupfava kwezvikamu uye tembiricha yenzvimbo inoshandiswa.
Hunhu hwema ether e cellulose hunoenderana nerudzi, huwandu uye kugoverwa kwezvinotsiva. Kurongwa kwe ether e cellulose kunoenderanawo nerudzi rwezvinotsiva, mwero we ether, kunyungudika uye hunhu hwakabatana hwekushandisa. Zvichienderana nerudzi rwezvinotsiva pa molecular chain, inogona kukamurwa kuita monoether uye mixed ether. MC yatinowanzo shandisa imonoether, uye HPMC imixed ether. Methyl cellulose ether MC chigadzirwa mushure mekunge hydroxyl group iri pa glucose unit ye natural cellulose inotsiviwa ne methoxy. Fomura yekuvaka ndiyo [COH7O2(OH)3-h(OCH3)h]x. Chikamu cheboka rehydroxyl chiri payuniti chinotsiviwa neboka remethoxy, uye chimwe chikamu chinotsiviwa neboka rehydroxypropyl, fomura yechimiro ndeye [C6H7O2(OH)3-mn(OCH3)m[OCH2CH(OH)CH3] n]x Ethyl methyl cellulose ether HEMC, idzi ndidzo mhando huru dzinoshandiswa zvakanyanya uye dzinotengeswa mumusika.
Panyaya yekunyungudika, inogona kukamurwa kuita ionic neisina ionic. Ma ether e non-ionic cellulose anonyungudika mumvura anonyanya kuumbwa ne alkyl ethers mbiri dzakatevedzana uye hydroxyalkyl ethers. Ionic CMC inonyanya kushandiswa mu sipo dzekugadzira, kudhinda nekudhaya machira, kutsvaga chikafu nemafuta. Non-ionic MC, HPMC, HEMC, nezvimwewo zvinonyanya kushandiswa mukuvaka, latex coatings, mishonga, makemikari ezuva nezuva, nezvimwewo. Anoshandiswa se thickener, water retaining agent, stabilizer, dispersant uye film forming agent.
Kuchengetwa kwemvura kwe cellulose ether: Mukugadzirwa kwezvinhu zvekuvaka, kunyanya dry powder mortar, cellulose ether ine basa risingatsiviwi, kunyanya mukugadzirwa kwe special mortar (modified mortar), chinhu chakakosha uye chakakosha. Basa rakakosha re water-soluble cellulose ether mu mortar rine zvinhu zvitatu:
1. Kugona kuchengetedza mvura zvakanaka
2. Mhedzisiro pakuenderana kwedhaka uye thixotropy
3. Kudyidzana nesimende.
Kuchengetwa kwemvura kwe cellulose ether kunoenderana nekutorwa kwemvura kwechigadziko chesimbi, kuumbwa kwesimbi, ukobvu hwesimbi, kudiwa kwemvura kwesimbi, uye nguva yekuiswa kwezvinhu. Kuchengetwa kwemvura kwe cellulose ether pachayo kunobva mukunyungudika uye kupera simba kwe cellulose ether pachayo. Sezvatinoziva tese, kunyangwe cellulose molecular chain ine huwandu hwakawanda hwe OH groups dzinokwanisa kunyungudika, hainyungudike mumvura, nekuti chimiro che cellulose chine mwero wepamusoro we crystallinity. Kugona kwe hydration kwe hydroxyl groups chete hakuna kukwana kufukidza hydrogen bonds dzakasimba uye van der Waals forces pakati pemamorekuru. Saka, inongozvimba asi hainyungudike mumvura. Kana substituent ikapinzwa mu molecular chain, substituent haisi iyo chete inoparadza hydrogen chain, asiwo interchain hydrogen bond inoparadzwa nekuda kwe wedging ye substituent pakati pemaketani ari pedyo. Substituent yakakura, daro riri pakati pemamorekuru rakakura. Daro riripo. Kana hydrogen bonds ikapararira zvakanyanya, cellulose ether inonyungudika mumvura mushure mekunge cellulose lattice yawedzera uye mhinduro yapinda, zvichiita mhinduro ine viscosity yakawanda. Kana tembiricha yakwira, hydration yepolymer inoderera, uye mvura iri pakati pemaketani inodzingwa. Kana mvura yapera yakakwana, mamorekuru anotanga kuungana, achigadzira gel yechimiro che network ine mativi matatu uye inopetwa.
Nguva yekutumira: Zvita-06-2022