Cellulose ethers yog cov polymers tsim los ntawm cov cellulose ntuj thiab hloov kho tshuaj. Cellulose ether yog ib qho derivative ntawm cellulose ntuj. Tsis zoo li cov polymers tsim, cellulose ether ntau lawm yog raws li cellulose, cov khoom siv yooj yim tshaj plaws, ib qho tshuaj polymer ntuj. Vim yog qhov tshwj xeeb ntawm cov qauv cellulose ntuj, cellulose nws tus kheej tsis muaj peev xwm los cuam tshuam nrog cov neeg sawv cev etherizing. Txawm li cas los xij, tom qab kev kho mob ntawm cov tshuaj solubilizers, cov hydrogen bonds muaj zog ntawm thiab hauv cov saw molecular raug rhuav tshem, thiab cov hydroxyl pawg ua haujlwm raug tso tawm rau hauv alkali cellulose nrog lub peev xwm los cuam tshuam, thiab tom qab cov tshuaj tiv thaiv ntawm tus neeg sawv cev etherizing ib pawg OH raug hloov mus rau hauv ib pawg OR kom tau txais cellulose ether.
Cov cellulose ethers muaj cov nyhuv uas ua rau huab cua nkag tau rau cov khoom siv cementitious tshiab. Cellulose ethers muaj ob qho tib si hydrophilic (hydroxyl, ether) thiab hydrophobic (methyl, glucose ring) pawg thiab yog cov surfactants nrog kev ua haujlwm ntawm qhov chaw thiab yog li muaj cov nyhuv uas ua rau huab cua nkag tau. Cov nyhuv uas ua rau huab cua nkag tau ntawm cellulose ether yuav tsim cov nyhuv "pob", uas tuaj yeem txhim kho kev ua haujlwm ntawm cov khoom tshiab, xws li ua kom cov plasticity thiab du ntawm cov mortar thaum lub sijhawm ua haujlwm, uas yog qhov zoo rau kev nthuav dav ntawm cov mortar; nws tseem yuav txhim kho cov txiaj ntsig ntawm cov mortar thiab txo tus nqi ntawm kev tsim cov mortar; txawm li cas los xij, nws yuav ua rau cov porosity ntawm cov khoom tawv thiab txo nws lub zog thiab elastic modulus, thiab lwm yam. Cov khoom siv kho tshuab.
Ua ib qho surfactant, cellulose ether kuj muaj cov nyhuv ntub lossis lubricating rau cov cement me me, uas ua ke nrog nws cov nyhuv cua-entraining ua rau cov khoom cementitious fluidity ntau dua, tab sis nws cov nyhuv thickening txo qhov fluidity, thiab cov nyhuv ntawm cellulose ether rau cov fluidity ntawm cov khoom cementitious yog kev sib xyaw ua ke ntawm cov plasticizing thiab thickening effects. Feem ntau hais lus, thaum tus nqi ntawm cellulose ether tsawg heev, nws feem ntau qhia cov nyhuv ntawm plasticization lossis dej txo; thaum tus nqi siab, cov nyhuv thickening ntawm cellulose ether nce sai, thiab nws cov nyhuv cua-entraining feem ntau saturate, yog li nws qhia cov nyhuv thickening lossis ua rau cov dej xav tau ntau dua.
Lub sijhawm tshaj tawm: Plaub Hlis-24-2022