Cellulose ether waa isku-dhis polymer ah oo laga sameeyay cellulose dabiici ah iyada oo loo marayo habka etherification, waana mid aad u fiican oo dhumuc weyn iyo wakiilka haynta biyaha.
Taariikhda Cilmi-baarista
Ether-yada Cellulose-ka ayaa si weyn loogu isticmaalay hoobiye qalalan oo isku dhafan sannadihii ugu dambeeyay, kuwa ugu badan ee la isticmaalo waa qaar ka mid ah ether-yada cellulose-ka aan ionic ahayn, oo ay ku jiraan methyl cellulose ether (MC), hydroxyethyl cellulose ether (HEC), hydroxyethyl cellulose ether Methyl cellulose ether (HEMC) iyo hydroxypropyl methyl cellulose ether (HPMC). Waqtigan xaadirka ah, ma jiraan qoraallo badan oo ku saabsan habka cabbirka ee viscosity-ga ee xalka ether cellulose. Dalkeenna, kaliya heerarka iyo monographs qaarkood ayaa qeexaya habka tijaabada ee viscosity-ga ee xalka ether cellulose.
Habka diyaarinta xalka ether-ka ee cellulose
Diyaarinta Xalka Methyl Cellulose Ether
Ether-ka cellulose-ka ee Methyl waxay tilmaamayaan ether-yada cellulose-ka oo ka kooban kooxaha methyl-ka ee molecule-ka, sida MC, HEMC iyo HPMC. Sababtoo ah hydrophobic-ka kooxda methyl-ka, xalalka cellulose ether ee ka kooban kooxaha methyl-ka waxay leeyihiin sifooyin jelaynta kulaylka, taas oo ah, kuma milmi karaan biyaha kulul heerkul ka sarreeya heerkulka jelaynta (qiyaastii 60-80°C). Si looga hortago in xalka ether-ka cellulose-ka uu sameeyo agglomerates, kululee biyaha ka sarreeya heerkulkooda jel, qiyaastii 80~90°C, ka dibna ku dar budada ether-ka cellulose-ka biyaha kulul, walaaq si ay u kala firdhaan, sii wad walaaqidda oo qabooji heerkulka la dejiyay, waxaa loo diyaarin karaa xal ether-ka cellulose-ka oo isku mid ah.
Sifooyinka milmida ee ether-yada ka kooban methylcellulose ee aan dusha sare lagu daweyn
Si looga fogaado isku-darka ether-ka cellulose inta lagu jiro habka kala-diridda, soosaarayaashu mararka qaarkood waxay sameeyaan daawaynta dusha sare ee kiimikada ee alaabada ether-ka cellulose ee budada ah si ay dib ugu dhigaan kala-diridda. Habka kala-diridda waxay dhacdaa ka dib marka ether-ka cellulose uu si buuxda u kala firdho, sidaa darteed si toos ah ayaa loogu kala firdhin karaa biyo qabow oo leh qiime pH dhexdhexaad ah iyada oo aan la samayn agglomerates. Qiimaha pH ee xalka oo sarreeya, waqtiga kala-diridda ee ether-ka cellulose oo leh sifooyin kala-diridda oo dib u dhacay. Hagaaji qiimaha pH ee xalka qiimo sare. Alkalinity waxay meesha ka saari doontaa milmida dib u dhaca ee ether-ka cellulose, taasoo keenta in ether-ka cellulose uu sameeyo agglomerates marka uu milmo. Sidaa darteed, qiimaha pH ee xalka waa in la kordhiyaa ama la dhimaa ka dib marka ether-ka cellulose uu si buuxda u kala firdho.
Sifooyinka milmida ee ether-yada ay ku jiraan methylcellulose ee dusha sare lagu daweeyay
Diyaarinta Xalka Hydroxyethyl Cellulose Ether
Xalka Hydroxyethyl cellulose ether (HEC) ma laha sifooyinka jelitaanka kulaylka, sidaa darteed, HEC oo aan lahayn daaweynta dusha sare waxay sidoo kale samayn doontaa agglomerates biyaha kulul. Soo-saarayaashu guud ahaan waxay sameeyaan daaweynta dusha sare ee kiimikada HEC budada ah si ay u dib u dhigaan kala dirista, si toos ah loogu kala firdhiyo biyo qabow oo leh qiime pH dhexdhexaad ah iyada oo aan la samayn agglomerates. Sidoo kale, xal leh alkalinity sare, HEC Waxay sidoo kale samayn kartaa agglomerates sababtoo ah luminta milanka dib u dhaca. Maadaama slurry-ku uu yahay alkaline ka dib fuuq-baxa qiimaha pH-na uu yahay inta u dhaxaysa 12 iyo 13, heerka kala dirista ee ether cellulose-ka lagu daweeyay dusha sare ee slurry-ka sibidhka sidoo kale aad ayuu u dhakhso badan yahay.
Sifooyinka milmida ee HEC-da lagu daweeyay dusha sare
Gunaanad iyo Falanqayn
1. Habka kala-fidinta
Si looga fogaado waxyeellooyinka soo gaara wakhtiga tijaabada sababtoo ah kala dirida gaabiska ah ee walxaha lagu daweeyo dusha sare, waxaa lagu talinayaa in la isticmaalo biyo kulul diyaarinta.
2. Habka qaboojinta
Xalka Cellulose ether waa in la walaaqaa oo la qaboojiyaa heerkulka deegaanka si loo yareeyo heerka qaboojinta, taas oo u baahan waqtiyo tijaabo oo dheeraad ah.
3. Habka walaaqidda
Ka dib marka ether-ka cellulose lagu daro biyaha kulul, hubi inaad sii walaaqdo. Marka heerkulka biyuhu hoos uga dhaco heerkulka jelka, ether-ka cellulose wuxuu bilaabi doonaa inuu milmo, xalkana si tartiib tartiib ah ayuu u noqon doonaa mid fiiqan. Waqtigan, waa in la dhimo xawaaraha walaaqidda. Ka dib marka xalku gaaro dheellitir gaar ah, wuxuu u baahan yahay inuu istaago in ka badan 10 saacadood ka hor inta xumbadu si tartiib tartiib ah ugu dul sabbeeyaan dusha sare si ay u qarxaan oo ay u baaba'aan.
Xumbo Hawo ah oo ku jira Xalka Cellulose Ether
4. Habka fuuq-celinta
Tayada ether-ka cellulose iyo biyaha waa in si sax ah loo cabbiraa, oo isku day inaadan sugin in xalka uu gaaro daxal sare ka hor inta aan la buuxin biyaha.
5. Tijaabada viscosity
Sababtoo ah thixotropy-ga xalka cellulose ether, marka la tijaabinayo viscosity-giisa, marka rotor-ka viscometer-ka wareega la geliyo xalka, wuxuu khalkhal gelin doonaa xalka wuxuuna saameyn doonaa natiijooyinka cabbirka. Sidaa darteed, ka dib marka rotor-ka la geliyo xalka, waa in loo oggolaadaa inuu istaago 5 daqiiqo ka hor inta aan la tijaabin.
Waqtiga boostada: Maarso-22-2023