Cellulose ether yog ib qho tseem ceeb ntawm cov khoom siv polymer uas tau siv dav hauv cov khoom siv, tshuaj, khoom noj thiab lwm yam. Nws cov khoom tuav dej yog ib qho tseem ceeb rau nws lub luag haujlwm hauv ntau daim ntawv thov. Cov dej tuav tau ncaj qha cuam tshuam rau adhesion, ductility thiab kev tsim kho ntawm cov khoom. Qhov ntsuas etherification thiab kub ntawm cellulose ether yog ob qho tseem ceeb uas cuam tshuam rau nws cov dej tuav.
Cov nyhuv ntawm etherification degree ntawm cellulose ether ntawm dej tuav
Cellulose ethers yog tsim los ntawm kev hloov cov hydroxyl ib feem ntawm cellulose rau hauv ether pawg. Lub degree ntawm etherification yog hais txog tus naj npawb ntawm ether pawg qhia nyob rau hauv txhua chav tsev piam thaj, uas yog siv los ntsuas qhov degree ntawm hloov cellulose ethers. Qib ntawm etherification muaj feem cuam tshuam rau cov dej tuav ntawm cellulose ethers. Feem ntau hais lus, raws li qib ntawm etherification nce, hydrophilicity ntawm cellulose ether nce, thiab nws cov dej tuav kev ua tau zoo kuj nce.
Qhov siab dua ntawm etherification, ntau pawg hydrophilic (xws li methoxy, ethoxy, thiab lwm yam) tau nkag mus rau hauv cellulose ether molecular saw. Cov pab pawg no tuaj yeem cuam tshuam nrog dej molecules los ntawm hydrogen bonds, ntxiv dag zog rau cellulose Lub peev xwm adsorption ntawm ether rau dej molecules. Yog li ntawd, cellulose ethers nrog ntau dua etherification degrees tuaj yeem nqus tau thiab khaws cov dej ntau hauv qhov chaw ntub dej, ua rau lawv zoo heev hauv cov dej tuav.
Txawm li cas los xij, qhov siab dua qib ntawm etherification, qhov zoo dua. Thaum cov qib ntawm etherification nce mus txog ib theem, cov dej tuav ntawm cellulose ether yuav tsis txuas ntxiv ntxiv nrog rau qhov nce qib ntawm etherification, thiab tej zaum yuav txo qis. Qhov no yog vim hais tias thaum lub etherification siab dhau lawm, cov qauv ntawm cov cellulose ether molecular saw yuav hloov, ua rau lub zog ntawm intermolecular zog, thaum kawg cuam tshuam nws cov dej nqus thiab tuav dej. Yog li ntawd, hauv kev siv cov tswv yim, cellulose ethers nrog cov qib etherification tsim nyog yuav tsum tau xaiv raws li qhov xwm txheej tshwj xeeb.
Qhov cuam tshuam ntawm qhov kub ntawm cov dej tuav ntawm cellulose ethers
Kub yog lwm qhov tseem ceeb uas muaj feem cuam tshuam rau cov dej tuav ntawm cellulose ethers. Nyob rau hauv cov xwm txheej kub sib txawv, cov dej tuav cov khoom ntawm cellulose ethers coj txawv. Feem ntau, qhov nce ntawm qhov kub yuav ua rau txo qis hauv cov dej tuav ntawm cellulose ethers. Qhov no feem ntau yog vim qhov kub thiab txias ua kom cov evaporation ntawm dej, ua rau nws nyuaj rau cov khoom khaws cov dej noo.
Thaum qhov kub qis dua, kev sib cuam tshuam ntawm cellulose ether molecules thiab dej molecules muaj zog dua, ua rau cov dej tuav tau zoo dua. Raws li qhov kub thiab txias, dej molecules evaporate sai dua, thiab cov dej tuav lub peev xwm ntawm cellulose ether maj mam tsis muaj zog. Tsis tas li ntawd, qhov kub thiab txias tuaj yeem cuam tshuam rau solubility ntawm cellulose ethers. Nyob rau hauv tej yam kub kub, cellulose ether yuav poob solubility thiab tsis tsim ib tug zoo xws li cov tshuaj los yog colloid, yog li cuam tshuam rau nws cov dej tuav.
Nws yog tsim nyog sau cia tias ntau hom cellulose ethers muaj qhov sib txawv rhiab heev rau qhov kub thiab txias. Qee cov cellulose ethers tseem tuaj yeem tswj xyuas cov dej zoo ntawm qhov kub siab dua, thaum lwm tus yuav muaj qhov txo qis hauv dej tuav thaum qhov kub nce me ntsis. Yog li ntawd, thaum xaiv cellulose ether, nws yog ib qho tsim nyog los xaiv qhov tsim nyog raws li qhov kub thiab txias ntawm qhov chaw siv.
Kev sib cuam tshuam ntawm degree ntawm etherification thiab kub
Cov teebmeem ntawm etherification degree thiab kub ntawm cov dej tuav ntawm cellulose ether feem ntau sib tham sib. Hauv kev siv tswv yim, ob yam no feem ntau yuav tsum tau txiav txim siab ua tiav. Piv txwv li, thaum cellulose ether nrog ib tug high degree ntawm etherification yog siv nyob rau hauv ib tug high-kub ib puag ncig, txawm hais tias qhov siab ntawm etherification tuaj yeem txhim kho cov dej tuav ntawm cellulose ether, tus nqi evaporation ntawm cov dej nyob rau hauv ib puag ncig high-temperature yuav kuj yog. accelerated raws li, yog li tsis muaj zog nws cov dej tuav cov nyhuv. Yog li ntawd, nyob rau hauv high-temperature ib puag ncig, nws yuav tsum tau siv cellulose ethers nrog tshwj xeeb hloov cov qauv los txhim kho lawv cov high-temperature resistance thiab dej tuav.
Ntawm qhov tsis sib xws, nyob rau hauv qhov kub thiab txias ib puag ncig, cov nyhuv ntawm etherification degree ntawm cov dej tuav ntawm cellulose ether yuav pom tseeb dua. Nyob rau hauv qhov kub thiab txias, dej evaporates maj mam, thiab cellulose ether nrog qib siab ntawm etherification tuaj yeem ua tiav nws cov dej nqus dej, yog li txhim kho cov dej tuav ntawm cov khoom.
Qhov ntsuas etherification thiab kub ntawm cellulose ether yog qhov tseem ceeb cuam tshuam rau nws cov dej tuav dej. Qhov siab dua qib ntawm etherification, qhov muaj zog hydrophilicity ntawm cellulose ether thiab cov dej tuav tau zoo dua. Txawm li cas los xij, qhov siab dhau ntawm etherification tuaj yeem ua rau muaj kev hloov pauv hauv cov qauv molecular, yog li cuam tshuam rau dej tuav. Qhov kub nce feem ntau ua rau txo qis hauv dej tuav ntawm cellulose ethers. Tshwj xeeb tshaj yog nyob rau hauv ib puag ncig kub, dej evaporation accelerates, cuam tshuam cov dej tuav nyhuv. Hauv kev siv cov tswv yim, nws yog ib qho tsim nyog los xaiv cov cellulose ether nrog rau qib tsim nyog ntawm etherification raws li qhov kub thiab txias thiab kev siv cov kev cai kom ua tiav cov dej tuav zoo tshaj plaws.
Lub sij hawm xa tuaj: Sep-18-2024