Cellulose ether i polymer yekugadzira yakagadzirwa ne cellulose yechisikigo seyakagadzirwa nekugadzirisa kemikari. Cellulose ether inotorwa kubva kune yakasikwa cellulose, cellulose ether kugadzirwa uye synthetic polymer zvakasiyana, chinhu chayo chinonyanya kukosha ndeye cellulose, yakasikwa polymer makomisheni. Nekuda kwekusarudzika kwechisikigo cellulose chimiro, cellulose pachayo haina kukwanisa kuita ne etherifying agent. Asi mushure mekurapa kwekuzvimba mumiririri, iyo yakasimba yehydrogen zvisungo pakati pecheni dzemamorekuru nemaketani zvakaparadzwa, uye basa reboka rehydroxyl rakaburitswa mualkali cellulose nekugona kuita, uye cellulose ether yakawanikwa kuburikidza nekuita kweetherifying agent - OH boka kupinda. - KANA boka.
Zvinhu zve cellulose ethers zvinoenderana nerudzi, nhamba uye kugovera kwezvinotsiva. Kurongeka kwe cellulose ether zvakare kunobva pamhando yezvinotsiva, dhigirii reetherification, solubility uye ine hukama application inogona kuiswa. Zvinoenderana nerudzi rwezvinotsiva pane molecular cheni, inogona kukamurwa kuita imwe ether uye yakasanganiswa ether. MC inowanzoshandiswa seether imwe chete, nepo HPmc iri musanganiswa ether. Methyl cellulose ether MC is a natural cellulose glucose unit pa hydroxyl is methoxide inotsiviwa ne product structure formula [CO H7O2 (OH) 3-H (OCH3) H] X, hydroxypropyl methyl cellulose ether HPmc chikamu chiri pahydroxyl chikamu. yemethoxide yakatsiviwa, chimwe chikamu chehydroxypropyl chakatsiviwa chigadzirwa, Iyo yemaitiro formula ndeye. [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X uye hydroxyethyl methyl cellulose ether HEmc, iyo inoshandiswa zvakanyanya uye inotengeswa pamusika.
Kubva pane solubility inogona kukamurwa kuita ionic mhando uye isiri-ionic mhando. Mvura-inonyungudika isiri-ionic cellulose ether inonyanya kuumbwa nealkyl ether uye hydroxyl alkyl ether maviri akatevedzana emhando. Ionic Cmc inonyanya kushandiswa mukugadzira detergent, machira, kudhinda, chikafu uye petroleum kushandiswa. Non-ionic MC, HPmc, HEmc uye zvimwe zvinonyanya kushandiswa mukuvaka zvinhu, latex coatings, mushonga, zuva nezuva chemistry uye zvimwe zvinhu. Sezvinoita thickening agent, mvura yekuchengeta mumiririri, stabilizer, dispersant, film forming agent.
Cellulose ether kuchengetedza mvura
Mukugadzirwa kwezvinhu zvekuvaka, kunyanya yakaoma yakasanganiswa dhaka, cellulose ether inoita basa risingadzokerike, kunyanya mukugadzirwa kwedhaka rakakosha (yakagadziridzwa dhaka), chikamu chakakosha.
Basa rakakosha remvura-soluble cellulose ether mudhaka rinonyanya kuita zvinhu zvitatu, imwe inyanzvi yekuchengetedza mvura, chechipiri iko pesvedzero yedhaka kusachinja-chinja uye thixotropy, uye chechitatu ndiko kudyidzana nesamende.
Cellulose ether kuchengetwa kwemvura, zvinoenderana nehwaro hwe hydroscopicity, kuumbwa kwedhaka, dhaka layer ukobvu, kudiwa kwemvura yedhaka, condensation zvinhu condensation nguva. Kuchengetwa kwemvura kwe cellulose ether kunobva mukunyungudika uye kupera simba kweselulosi ether pachayo. Zvinonyatsozivikanwa kuti cellulose molecular chain, kunyange zvazvo iine nhamba huru yezvikwata zveH hydrated zvakanyanya, zvisinganyunguriki mumvura nekuda kwechimiro chavo checrystalline. Iko hydration kugona kwemapoka ehydroxyl chete haina kukwana kubhadhara kune yakasimba intermolecular hydrogen bond uye van der Waals masimba. Kana zvinotsiva zvinounzwa mucheni yemamorekuru, kwete chete zvinotsiva zvinoparadza cheni yehydrogen, asiwo iyo interchain hydrogen zvisungo zvinoputswa nekuda kwekuroora kwevanotsiva pakati pemaketani ari padyo. Iyo yakakura iyo inotsiva, yakakura chinhambwe pakati pemamorekuru. Kunyanya kuparadzwa kwehydrogen bond effect, cellulose lattice kuwedzera, mhinduro mu cellulose ether inonyungudika mumvura, kuumbwa kwepamusoro viscosity solution. Sezvo tembiricha inokwira, iyo hydration yepolymer inodzikira uye mvura pakati pemaketani inodzingwa kunze. Kana iyo dehydrating effect yakakwana, mamorekuru anotanga kuungana uye gel rinopeta kunze mumatatu-dimensional network. Zvinhu zvinokanganisa kuchengetwa kwemvura kwedhaka zvinosanganisira cellulose ether viscosity, dosi, particle fineness uye tembiricha yebasa.
Iyo yakakura viscosity ye cellulose ether, zviri nani kuchengetedza mvura kuita, viscosity yepolymer solution. Huremu hwemamorekuru (dhigirii repolymerization) yepolymer inotemerwawo nehurefu uye morphology yechimiro chemolecular yeketani, uye kugoverwa kwenhamba yezvinotsiva inokanganisa zvakananga chiyero che viscosity. [eta] = Km alpha
Intrinsic viscosity ye polymer mhinduro
M polymer molecular uremu
α polymer maitiro anogara aripo
K viscosity solution coefficient
Iyo viscosity yepolymer mhinduro inoenderana nehuremu hwemamorekuru epolymer. Iyo viscosity uye kusangana kwe cellulose ether mhinduro kune hukama kune akasiyana maapplication. Naizvozvo, yega yega cellulose ether ine akawanda akasiyana viscosity yakatarwa, viscosity regulation iri zvakare kunyanya kuburikidza nekuderedzwa kwealkali cellulose, kureva kutsemuka kwe cellulose molecular cheni kuti ibudirire.
Pakukura kwechidimbu, kutsetseka kwechikamu, kunova nani kuchengetedza mvura. Zvimedu zvakakura zve cellulose ether kusangana nemvura, iyo yepamusoro inonyunguduka pakarepo uye inogadzira gel yekuputira zvinhu kudzivirira mamorekuru emvura kuti arambe achipinda mukati, dzimwe nguva nguva yakareba ichibvongodza haigone kuparadzaniswa zvakaenzana kunyungudika, kuumbwa kwedhaka flocculent mhinduro kana agglomerate. Kunyungudika kwe cellulose ether chimwe chezvinhu zvekusarudza cellulose ether.
Kuomesa uye thixotropy ye cellulose ether
Mhedzisiro yechipiri ye cellulose ether - kukora kunoenderana ne: cellulose ether polymerization degree, solution concentration, shear rate, tembiricha uye mamwe mamiriro. Iyo gelation pfuma yemhinduro yakasarudzika kune alkyl cellulose uye yakagadziridzwa madhirivhari. Gelation maitiro ane hukama nedhigirii rekutsiva, kugadzirisa kugadzirisa uye zvinowedzera. Kune hydroxyl alkyl modified derivatives, gel zvivakwa zvine hukamawo nedhigirii rehydroxyl alkyl gadziriso. Nokuda kwekugadzirisa kwekugadzirisa kwepasi viscosity MC uye HPmc inogona kugadzirirwa 10% -15% yekugadzirisa mhinduro, yepakati viscosity MC uye HPmc inogona kugadzirirwa 5% -10% mhinduro uye high viscosity MC uye HPmc inogona kugadzirirwa 2% -3% mhinduro, uye kazhinji viscosity ye cellulose ether inoiswawo grade ne 1% -2% mhinduro. Yakakwira molecular uremu cellulose ether thickener kunyatsoshanda, iyo yakafanana yemhinduro, akasiyana mamolecular uremu mapolymer ane viscosity yakasiyana, viscosity uye molecular uremu zvinogona kuratidzwa sezvinotevera, [η] = 2.92 × 10-2 (DPn) 0.905, DPn ndiyo avhareji. polymerization degree repamusoro. Yakaderera molecular uremu cellulose ether kuwedzera zvimwe kuti uwane iyo inotarirwa viscosity. Viscosity yaro haina kutsamira pashear rate, yakakwira viscosity kuti iwane iyo inotarirwa viscosity, iyo mari inodiwa kuwedzera zvishoma, viscosity zvinoenderana nekukora kwekuita. Naizvozvo, kuti uwane kumwe kuenderana, imwe chiyero che cellulose ether (concentration yemhinduro) uye mhinduro viscosity inofanira kuvimbiswa. Iyo tembiricha yegelation yemushonga yakadzikira zvine mutsetse nekuwedzera kwekusangana kwemhinduro, uye gelation yakaitika pakamuri tembiricha mushure mekusvika kumwe kusungwa. HPmc ine yakakwira gelation concentration pakamuri tembiricha.
Kusagadzikana kunogonawo kugadziriswa nekusarudza particle size uye cellulose ethers ane madhigirii akasiyana ekugadzirisa. Iko kunonzi kugadziridzwa ndiko kuiswa kwehydroxyl alkyl boka mune imwe dhigirii yekutsiva pane skeleton chimiro cheMC. Nekushandura hukama hwekutsinhanisa hunhu hwezviviri zvinotsiva, kureva, iyo DS neMS inotsinhanisa tsika dzemethoxy uye hydroxyl mapoka. Zvimiro zvakasiyana-siyana zve cellulose ether zvinodikanwa nekushandura hukama hunotsiviwa hwemhando mbiri dzezvinotsiva.
hukama huri pakati pekuenderana uye kugadzirisa. Mumufananidzo 5, kuwedzerwa kwe cellulose ether kunokanganisa kushandiswa kwemvura kwedhaka uye kunoshandura mvura-binder ratio yemvura nesamende, iyo ndiyo iyo inowedzera simba. Iyo yakakwirira iyo dosi, iyo inowedzera kushandiswa kwemvura.
Cellulose ethers inoshandiswa muupfu zvekuvaka zvinhu zvinofanirwa kunyungudika nekukurumidza mumvura inotonhora uye kupa iyo sisitimu kuenderana kwayo. Kana iyo shear rate yakapihwa ichiri flocculent uye colloidal chinhu chakaderera kana chakashata chemhando chigadzirwa.
Kune zvakare hukama hwakanaka hwemutsara pakati pesimende slurry kuenderana uye dosi ye cellulose ether, cellulose ether inogona kuwedzera zvakanyanya viscosity yedhaka, iyo yakakura dosage, zvakanyanya kujeka mhedzisiro.
Cellulose ether aqueous solution ine high viscosity ine yakakwirira thixotropy, inova imwe yemaitiro e cellulose ether. Aqueous mhinduro dzeMc mhando mapolymers anowanzo aine pseudoplastic, asiri-thixotropic fluidity pazasi petembiricha yavo yegel, asi Newtonian inoyerera zvivakwa pazasi shear mitengo. Pseudoplasticity inowedzera nekuwedzera kwehuremu hwemamorekuru kana kuwanda kwe cellulose ether uye inozvimiririra kune inotsiva mhando nedhigirii. Naizvozvo, cellulose ethers yegiredhi rimwechete viscosity, ingave MC, HPmc kana HEmc, inogara ichiratidza zvakafanana rheological properties chero bedzi iyo yekuisa uye tembiricha inoramba iripo. Apo kutonhora kunowedzera, gel yemaitiro inoumbwa uye yakakwirira thixotropic inoyerera inoitika. Cellulose ethers ine high concentration uye yakaderera viscosity inoratidza thixotropy kunyange pasi pekushisa kwegel. Ichi chivakwa chinobatsira zvikuru pakuvaka dhaka rekuvaka kuti rigadzirise kuyerera kwayo uye kuyerera kwakarembera chivakwa. Zvinoda kutsanangurwa pano kuti kukwirisa viscosity ye cellulose ether, zviri nani kuchengetwa kwemvura, asi iyo yakakwira viscosity, iyo inokwira yakaenzana molecular uremu hwe cellulose ether, kuderera kunoenderana nekunyungudika kwayo, izvo zvinokanganisa iyo dhaka concentration uye kuita kwekuvaka. Iyo yakakwirira viscosity, iyo inonyanya kuoneka iyo thickening mhedzisiro yedhaka, asi haisi hukama hwakakwana hwakaenzana. Imwe yakaderera viscosity, asi yakagadziridzwa cellulose ether mukuvandudza kusimba kwemaitiro edhaka rakanyorova rine kuita kwakanakisa, pamwe nekuwedzera kweviscosity, cellulose ether kuchengetwa kwemvura kwakavandudzwa.
Nguva yekutumira: Mar-30-2022