I-Cellulose ether yipolymer yokwenziwa eyenziwe kwi-cellulose yendalo ngokuguqulwa kweekhemikhali.I-ether ye-cellulose iphuma kwi-cellulose yendalo.Ukuveliswa kwe-cellulose ether kuyahluka kwiipolymers zokwenziwa.Izinto zayo ezisisiseko ziyi-cellulose, i-polymer compound yendalo.Ngenxa yobungcali besakhiwo se-cellulose yendalo, i-cellulose ngokwayo ayinakho ukusabela kunye nee-etherification agents.Nangona kunjalo, emva kokunyangwa kwe-ejenti yokuvuvukala, iibhondi ze-hydrogen ezinamandla phakathi kwamatyathanga e-molecular kunye namatyathanga atshatyalaliswa, kwaye ukukhutshwa okusebenzayo kweqela le-hydroxyl kuba yi-alkali cellulose esebenzayo.Fumana i-cellulose ether.
Iimpawu ze-cellulose ethers zixhomekeke kuhlobo, inani kunye nokuhanjiswa kwezinto ezithatha indawo.Ulwahlulo lwe-cellulose ethers lukwasekelwe kuhlobo lwabaxumi, i-degree of etherification, i-solubility kunye neepropati ezinxulumene nesicelo.Ngokohlobo lwababambeleyo kwitsheyini yemolekyuli, inokwahlulwa ibe yi-monoether kunye ne-ether edibeneyo.Siqhele ukusebenzisa i-mc njenge-monoether, kunye ne-HPmc njenge-ether exutywe.I-Methyl cellulose ether mc yimveliso emva kweqela le-hydroxyl kwiyunithi ye-glucose ye-cellulose yendalo ifakwe endaweni yeqela le-methoxy.Yimveliso efunyenwe ngokutshintsha inxalenye yeqela le-hydroxyl kwiyunithi kunye neqela le-methoxy kunye nenye inxalenye kunye neqela le-hydroxypropyl.Ifomula yolwakhiwo ithi [C6H7O2(OH)3-mn(OCH3)m[OCH2CH(OH)CH3]n]x Hydroxyethyl methyl cellulose ether HEmc, ezi zezona ntlobo zisetyenziswa kakhulu kwaye zithengiswa kwimarike.
Ngokubhekiselele kwi-solubility, inokwahlulwa ibe yi-ionic kunye ne-non-ionic.Ii-ether ze-cellulose ezingenayo i-ionic ezinyibilikayo zamanzi zenziwa ikakhulu ngamacandelo amabini e-alkyl ethers kunye ne-hydroxyalkyl ethers.I-Ionic Cmc isetyenziswa ikakhulu kwizicoci zokwenziwa, ukuprintwa kwelaphu kunye nokudaya, ukutya kunye nokuhlola ioli.I-non-ionic mc, i-HPmc, i-HEmc, njl. zisetyenziswa kakhulu kwizinto zokwakha, iingubo ze-latex, amayeza, iikhemikhali zemihla ngemihla, njl njl. Isetyenziswe njenge-thickener, i-agent yokugcina amanzi, i-stabilizer, i-dispersant kunye ne-agent yokwenza ifilimu.
Ukugcinwa kwamanzi kwe-cellulose ether
Ekuvelisweni kwezinto zokwakha, ngakumbi udaka oluxubeneyo olomileyo, i-cellulose ether idlala indima engenakuphinda ithathelwe indawo, ngakumbi kwimveliso yodaka olukhethekileyo (udaka olulungisiweyo), luyinto eyimfuneko kwaye ibalulekileyo.
Indima ebalulekileyo ye-ether ye-cellulose e-soluble yamanzi kwi-mortar ikakhulu inemiba emithathu, enye inamandla okugcina amanzi, enye yimpembelelo ehambelanayo kunye ne-thixotropy yodaka, kwaye okwesithathu kukusebenzisana nesamente.
Ukugcinwa kwamanzi kwi-ether ye-cellulose kuxhomekeke ekufunjweni kwamanzi kwinqanaba lesiseko, ukubunjwa kodaka, ubukhulu bodaka lodaka, imfuno yamanzi yodaka, kunye nexesha lokumisela izinto zokumisela.Ukugcinwa kwamanzi kwe-cellulose ether ngokwayo kuvela kwi-solubility kunye nokuphelelwa ngamanzi kwe-cellulose ether ngokwayo.Njengoko sonke sisazi, nangona i-cellulose i-molecular chain iqulethe inani elikhulu lamaqela e-OH anamandla, ayinyibiliki emanzini, kuba isakhiwo se-cellulose sinezinga eliphezulu le-crystallinity.Isakhono se-hydration samaqela e-hydroxyl iyodwa akwanelanga ukugubungela iibhondi ze-hydrogen ezomeleleyo kunye ne-van der Waals phakathi kwee-molecule.Ngoko ke, idumba kuphela kodwa ayinyibiliki emanzini.Xa i-substituent ingeniswa kwitsheyina le-molecular, kungekhona nje i-substituent etshabalalisa ikhonkco le-hydrogen, kodwa kunye ne-interchain ye-hydrogen bond iyatshatyalaliswa ngenxa yokutshatyalaliswa kwe-substituent phakathi kwamatyathanga akufutshane.Ubukhulu be-substitute, umgama omkhulu phakathi kweemolekyuli.Umgama mkhulu.Umphumo omkhulu wokutshabalalisa iibhondi ze-hydrogen, i-ether ye-cellulose iba yi-soluble yamanzi emva kokuba i-cellulose lattice yanda kwaye isisombululo singena, senza isisombululo esiphezulu se-viscosity.Xa izinga lokushisa liphakama, i-hydration ye-polymer iyancipha, kwaye amanzi phakathi kwamaketanga akhutshwa ngaphandle.Xa isiphumo sokuchithwa kwamanzi sanele, iamolekyu ziqala ukudibanisa, zenza i-gel yesakhiwo senethiwekhi ye-dimensional emithathu kwaye ihlanganiswe ngaphandle.Izinto ezichaphazela ukugcinwa kwamanzi kwi-mortar ziquka i-viscosity ye-cellulose ether, inani elongezelelweyo, ukucocwa kweengqungquthela kunye nokushisa kokusetyenziswa.
Ukuphakama kwe-viscosity ye-cellulose ether, ngcono ukusebenza kokugcinwa kwamanzi, kunye nokuphakama kwe-viscosity yesisombululo se-polymer.Ngokuxhomekeke kubunzima bemolekyuli (i-polymerization degree) yepolymer, iphinda igqitywe ngobude be-chain yesakhiwo se-molecular kunye nokumila kwekhonkco, kunye nokuhanjiswa kweentlobo kunye nobuninzi bezinto ezithintekayo nazo zichaphazela ngokuthe ngqo uluhlu lwe-viscosity.[η]=Kmα
[η] I-viscosity yangaphakathi yesisombululo sepolymer
m polymer ubunzima bemolekyuli
α ipholima yophawu olungaguqukiyo
K i-viscosity isisombululo se-coefficient
I-viscosity yesisombululo sepolymer ixhomekeke kubunzima be-molecular of polymer.I-viscosity kunye nokuxinwa kwesisombululo se-cellulose ether ihambelana nesicelo kwiinkalo ezahlukeneyo.Ke ngoko, i-ether yeselulosi nganye ineenkcazo ezininzi ezahlukeneyo ze-viscosity, kwaye uhlengahlengiso lwe-viscosity lubonakaliswa ikakhulu ngokuthotywa kwe-alkali cellulose, oko kukuthi, ukuqhawuka kwamakhonkco e-cellulose.
Ubuninzi be-ether ye-cellulose eyongeziweyo kwidaka, ngcono ukugcinwa kwamanzi, kunye nokuphakama kwe-viscosity, ngcono ukugcinwa kwamanzi.
Ubungakanani be-particle, i-fineral particle, ingcono ukugcinwa kwamanzi (jonga umfanekiso 3).Emva kokuba amasuntswana amakhulu e-cellulose ether adibane namanzi, umphezulu uyanyibilika ngokukhawuleza kwaye wenze ijeli ukusonga izinto zokuthintela iimolekyuli zamanzi ukuba zingaqhubeki nokungena.Ngamanye amaxesha ayinakuchithwa ngokulinganayo kwaye inyibilikiswe nasemva kwexesha elide, ukwenza isisombululo esinamafu okanye i-agglomeration.Ichaphazela kakhulu ukugcinwa kwamanzi kwe-cellulose ether, kunye ne-solubility yenye yezinto zokukhetha i-cellulose ether.
Ukuqina kunye Thixotropy yeCellulose Etere
Umsebenzi wesibini we-cellulose ether - ukuqina kuxhomekeke kwi: iqondo le-polymerization ye-cellulose ether, i-concentration concentration, i-shear rate, iqondo lokushisa kunye nezinye iimeko.Ipropati ye-gelling yesisombululo iyingqayizivele kwi-alkyl cellulose kunye ne-derivatives yayo eguqulwayo.Iimpawu ze-gelation zihambelana neqondo lokutshintshwa, ukugxininiswa kwesisombululo kunye nezongezo.Kwizinto ze-hydroxyalkyl eziguqulweyo, iipropathi zejeli nazo zihambelana neqondo lokuguqulwa kwe-hydroxyalkyl.Kwi-mc kunye ne-HPmc ene-viscosity ephantsi, i-10% -15% isisombululo soxinaniso sinokulungiswa, isisombululo se-5% -10% sinokulungiswa kwi-medium viscosity mc kunye ne-HPmc, kunye ne-2% -3% isisombululo sinokulungiswa kwi-high viscosity mc kunye HPmc, kwaye ngokuqhelekileyo Ukuhlelwa kwe-viscosity ye-ether ye-cellulose iphinda ihlelwe nge-1% -2% isisombululo.Ubunzima bemolekyuli ye-cellulose ether ephezulu inokuqina okuphezulu.Kwisisombululo esifanayo soxinaniso, iipolymers ezinobunzima obuhlukeneyo beemolekyuli zinee-viscosities ezahlukeneyo.Iqondo eliphezulu.I-viscosity ekujoliswe kuyo inokufezekiswa kuphela ngokudibanisa inani elikhulu le-molecular weight cellulose ether.I-viscosity yayo inokuxhomekeka okuncinci kwireyithi yokucheba, kwaye i-viscosity ephezulu ifikelela kwi-viscosity ekujoliswe kuyo, kwaye inani elifunekayo lokongeza lincinci, kwaye i-viscosity ixhomekeke ekusebenzeni kakuhle.Ngoko ke, ukufezekisa ukuhambelana okuthile, inani elithile le-cellulose ether (ukugxilwa kwesisombululo) kunye ne-viscosity yesisombululo kufuneka iqinisekiswe.Iqondo lokushisa le-gel yesisombululo liyancipha ngokuhambelana nokunyuka koxinzelelo lwesisombululo, kunye neegels kwiqondo lokushisa emva kokufikelela kwinqanaba elithile.I-concentration ye-gelation ye-HPmc iphezulu kwiqondo lokushisa.
Ukuhambelana kungalungiswa ngokukhetha ubungakanani besuntswana kunye nokukhetha i-cellulose ethers ngeedigri ezahlukeneyo zokuguqulwa.Into ebizwa ngokuba luhlengahlengiso kukwazisa iqondo elithile lokutshintshwa kwamaqela e-hydroxyalkyl kulwakhiwo lwamathambo e-mc.Ngokutshintsha amaxabiso ahambelanayo atshintshileyo amabini abambeleyo, oko kukuthi, i-DS kunye ne-ms ehambelanayo amaxabiso e-methoxy kunye ne-hydroxyalkyl esihlala siyithetha.Iimfuno ezahlukeneyo zokusebenza ze-cellulose ether zinokufunyanwa ngokutshintsha amaxabiso ahambelanayo ahambelanayo amabini abambeleyo.
I-cellulose ethers esetyenziswe kwizinto zokwakha ezinomgubo kufuneka ichithe ngokukhawuleza emanzini abandayo kwaye inike ukuhambelana okufanelekileyo kwesistim.Ukuba kunikwe umlinganiselo othile wokucheba, isuka ibe yibloko ejikelezayo kunye ne-colloidal, eyimveliso ekumgangatho ophantsi okanye ekumgangatho ophantsi.
Kukwakho nobudlelwane obuhle bomgca phakathi kokungaguquguquki kwentlama yesamente kunye nedosi ye-cellulose ether.I-ether ye-cellulose inokunyusa kakhulu i-viscosity yodaka.Ubukhulu bedosi, kokukhona umphumo ucaca ngakumbi, jonga uMfanekiso 6
I-high-viscosity cellulose ether isisombululo samanzi sine-thixotropy ephezulu, ekwayimpawu enkulu ye-cellulose ether.Izisombululo ezimanzi ze-Mc-type polymers zihlala zine-pseudoplastic kunye ne-non-thixotropic fluidity ngaphantsi kobushushu bejeli yazo, kodwa iipropati ezihamba ngeNewtonian kumazinga aphantsi okucheba.I-Pseudoplasticity iyanda kunye nobunzima be-molecular okanye i-concentration ye-cellulose ether, kungakhathaliseki ukuba luhlobo luni lwe-substitute kunye neqondo lokutshintshwa.Ngoko ke, i-cellulose ethers yebakala elifanayo le-viscosity, kungakhathaliseki ukuba i-mc, i-HPmc, i-HEmc, iya kuhlala ibonisa iimpawu ezifanayo ze-rheological nje ngokuba ugxininiso kunye nobushushu bugcinwa rhoqo.Iigels zesakhiwo zenziwe xa ubushushu buphakanyisiwe, kwaye ukuhamba okuphezulu kwe-thixotropic kwenzeka.Uxinzelelo oluphezulu kunye ne-viscosity ephantsi ye-cellulose ethers ibonisa i-thixotropy nangaphantsi kweqondo lokushisa le-gel.Lo mhlaba unenzuzo enkulu kuhlengahlengiso lomgangatho kunye nokuncipha kulwakhiwo lodaka lwesakhiwo.Kufuneka kucaciswe apha ukuba i-viscosity ephezulu ye-ether ye-cellulose, ngcono ukugcinwa kwamanzi, kodwa ukuphakama kwe-viscosity, ukuphakama kwe-molecular weight ye-cellulose ether, kunye nokuncipha okuhambelanayo kwi-solubility yayo, enempembelelo embi. kugxininiso lodaka kunye nokusebenza kolwakhiwo.Ukuphakama kwe-viscosity, kuyabonakala ngakumbi umphumo wokuqina kumdaka, kodwa awulingani ngokupheleleyo.Enye i-viscosity ephakathi kunye nephantsi, kodwa i-ether ye-cellulose eguqulwayo inomsebenzi ongcono ekuphuculeni amandla okwakhiwa kodaka olumanzi.Ngokunyuka kwe-viscosity, ukugcinwa kwamanzi kwe-cellulose ether kuphucula.
Ixesha lokuposa: Nov-22-2022