Qhov txawv ntawm MC thiab HPMC, HEC, CMC

1. Methylcellulose (MC)

Tom qab cov paj rwb ua kom zoo lawm raug kho nrog alkali, cellulose ether raug tsim los ntawm ntau qhov kev sib xyaw nrog methane chloride ua tus neeg sawv cev etherification. Feem ntau, qib kev hloov pauv yog 1.6 ~ 2.0, thiab qhov solubility kuj txawv nrog ntau qib kev hloov pauv. Nws yog rau cov cellulose ether uas tsis yog ionic.

(1) Methylcellulose yaj tau hauv dej txias, thiab nws yuav nyuaj rau yaj hauv dej kub. Nws cov kua dej ruaj khov heev hauv pH = 3 ~ 12. Nws muaj kev sib raug zoo nrog cov hmoov txhuv nplej siab, cov roj hmab guar, thiab lwm yam thiab ntau yam surfactants. Thaum qhov kub ncav cuag qhov kub gelation, gelation tshwm sim.

(2) Qhov khaws dej ntawm methyl cellulose nyob ntawm nws qhov ntxiv ntau npaum li cas, viscosity, qhov zoo ntawm cov khoom me me thiab qhov nrawm ntawm kev yaj. Feem ntau, yog tias qhov ntxiv ntau npaum li cas, qhov zoo me me, thiab qhov viscosity loj, qhov nrawm ntawm kev khaws dej siab. Ntawm lawv, qhov nrawm ntawm kev ntxiv muaj qhov cuam tshuam loj tshaj plaws rau qhov nrawm ntawm kev khaws dej, thiab qib ntawm viscosity tsis ncaj qha rau qib ntawm kev khaws dej. Qhov nrawm ntawm kev yaj feem ntau nyob ntawm qib ntawm kev hloov pauv ntawm qhov chaw ntawm cov khoom me me cellulose thiab qhov zoo ntawm cov khoom me me. Ntawm cov cellulose ethers saum toj no, methyl cellulose thiab hydroxypropyl methyl cellulose muaj qhov nrawm ntawm kev khaws dej siab dua.

(3) Kev hloov pauv ntawm qhov kub thiab txias yuav cuam tshuam loj heev rau qhov ceev ntawm cov methyl cellulose uas khaws dej. Feem ntau, qhov kub siab dua, qhov kev khaws dej yuav phem dua. Yog tias qhov kub ntawm cov mortar tshaj 40 ° C, qhov kev khaws dej ntawm methyl cellulose yuav raug txo qis, cuam tshuam loj heev rau kev tsim cov mortar.

(4) Methyl cellulose muaj feem cuam tshuam loj rau kev tsim kho thiab kev nplaum ntawm cov mortar. Qhov "kev nplaum" ntawm no yog hais txog lub zog nplaum uas hnov ​​​​​​ntawm tus neeg ua haujlwm lub cuab yeej thov thiab phab ntsa substrate, uas yog, qhov kev tiv thaiv shear ntawm cov mortar. Qhov kev nplaum yog siab, qhov kev tiv thaiv shear ntawm cov mortar yog loj, thiab lub zog uas cov neeg ua haujlwm xav tau hauv cov txheej txheem ntawm kev siv kuj loj, thiab kev ua haujlwm ntawm cov mortar tsis zoo. Methyl cellulose adhesion yog nyob rau theem nruab nrab hauv cov khoom cellulose ether.

2. Hydroxypropylmethylcellulose (HPMC)

Hydroxypropyl methylcellulose yog ib hom cellulose uas nws cov zis thiab kev siv tau nce sai heev nyob rau xyoo tas los no. Nws yog ib qho cellulose sib xyaw ether uas tsis yog ionic ua los ntawm paj rwb zoo tom qab alkalization, siv propylene oxide thiab methyl chloride ua tus neeg sawv cev etherification, los ntawm ntau yam kev tshuaj tiv thaiv. Qib ntawm kev hloov pauv feem ntau yog 1.2 ~ 2.0. Nws cov khoom sib txawv vim yog qhov sib txawv ntawm cov ntsiab lus methoxyl thiab cov ntsiab lus hydroxypropyl.

(1) Hydroxypropyl methylcellulose yooj yim yaj hauv dej txias, thiab nws yuav ntsib teeb meem hauv kev yaj hauv dej kub. Tab sis nws qhov kub gelation hauv dej kub yog siab dua li ntawm methyl cellulose. Qhov solubility hauv dej txias kuj zoo dua piv rau methyl cellulose.

(2) Qhov viscosity ntawm hydroxypropyl methylcellulose muaj feem cuam tshuam nrog nws qhov hnyav molecular, thiab qhov loj dua qhov hnyav molecular, qhov siab dua qhov viscosity. Kub kuj cuam tshuam rau nws qhov viscosity, thaum kub nce, viscosity txo qis. Txawm li cas los xij, nws qhov viscosity siab muaj qhov kub qis dua li methyl cellulose. Nws cov kua ruaj khov thaum khaws cia rau hauv chav sov.

(3) Qhov khaws cia dej ntawm hydroxypropyl methylcellulose nyob ntawm nws qhov ntxiv, viscosity, thiab lwm yam, thiab nws qhov khaws cia dej nyob rau hauv tib qhov ntxiv yog siab dua li ntawm methyl cellulose.

(4) Hydroxypropyl methylcellulose ruaj khov rau cov kua qaub thiab alkali, thiab nws cov kua dej ruaj khov heev hauv pH = 2 ~ 12. Caustic soda thiab dej txiv qaub tsis muaj feem cuam tshuam rau nws cov kev ua tau zoo, tab sis alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity nce ntxiv. Hydroxypropyl methylcellulose ruaj khov rau cov ntsev feem ntau, tab sis thaum qhov concentration ntawm cov ntsev ntau, qhov viscosity ntawm hydroxypropyl methylcellulose kua feem ntau nce ntxiv.

(5) Hydroxypropyl methylcellulose tuaj yeem sib xyaw nrog cov polymer sib xyaw uas yaj tau hauv dej los ua cov kua nplaum uas sib xws thiab viscosity siab dua. Xws li polyvinyl cawv, hmoov txhuv nplej siab ether, cov roj zaub, thiab lwm yam.

(6) Hydroxypropyl methylcellulose muaj kev tiv thaiv enzyme zoo dua li methylcellulose, thiab nws cov kua tsis tshua muaj peev xwm raug rhuav tshem los ntawm cov enzymes dua li methylcellulose. Qhov kev nplaum ntawm hydroxypropyl methylcellulose rau kev tsim kho mortar yog siab dua li ntawm methylcellulose.

3. Hydroxyethyl cellulose (HEC)

Nws yog ua los ntawm paj rwb zoo, kho nrog alkali, thiab ua ke nrog ethylene oxide ua tus neeg sawv cev etherification nyob rau hauv lub xub ntiag ntawm acetone. Qib ntawm kev hloov pauv feem ntau yog 1.5 ~ 2.0. Nws muaj hydrophilicity muaj zog thiab yooj yim nqus dej noo.

(1) Hydroxyethyl cellulose yaj tau hauv dej txias, tab sis nws nyuaj rau yaj hauv dej kub. Nws cov tshuaj ruaj khov ntawm qhov kub siab tsis muaj gelling. Nws tuaj yeem siv tau ntev hauv qhov kub siab hauv mortar, tab sis nws cov dej khaws cia qis dua li ntawm methyl cellulose.

(2) Hydroxyethyl cellulose ruaj khov rau cov kua qaub thiab alkali. Alkali tuaj yeem ua kom nws cov yaj sai dua thiab ua rau nws cov viscosity me ntsis. Nws cov dispersibility hauv dej yog qhov phem dua li ntawm methyl cellulose thiab hydroxypropyl methyl cellulose.

(3) Hydroxyethyl cellulose muaj kev ua tau zoo tiv thaiv kev qaug zog rau cov mortar, tab sis nws muaj lub sijhawm ntev dua rau cov cement.

(4) Kev ua tau zoo ntawm hydroxyethyl cellulose uas tsim los ntawm qee lub tuam txhab hauv tsev yog qhov qis dua li ntawm methyl cellulose vim nws cov dej ntau thiab cov tshauv ntau.

4. Carboxymethyl cellulose (CMC)

Ionic cellulose ether yog ua los ntawm cov fiber ntuj (paj rwb, thiab lwm yam) kho nrog alkali thiab siv los ua tus neeg sawv cev etherification los ntawm ntau yam kev kho mob tshuaj tiv thaiv. Qib ntawm kev hloov pauv feem ntau yog 0.4 ~ 1.4, thiab nws cov kev ua tau zoo cuam tshuam loj heev los ntawm qib ntawm kev hloov pauv.

(1) Carboxymethyl cellulose muaj hygroscopic ntau dua, thiab nws yuav muaj dej ntau dua thaum khaws cia rau hauv qab cov xwm txheej dav dav.

(2) Cov kua dej Carboxymethyl cellulose yuav tsis tsim cov gel, thiab qhov viscosity yuav txo qis nrog qhov nce ntawm qhov kub. Thaum qhov kub tshaj 50 ° C, qhov viscosity tsis rov qab tau.

(3) Nws qhov ruaj khov raug cuam tshuam los ntawm pH. Feem ntau, nws tuaj yeem siv rau hauv gypsum-based mortar, tab sis tsis yog hauv cement-based mortar. Thaum alkaline heev, nws poob viscosity.

(4) Nws cov dej khaws cia qis dua li ntawm methyl cellulose. Nws muaj cov nyhuv qeeb rau gypsum-based mortar thiab txo nws lub zog. Txawm li cas los xij, tus nqi ntawm carboxymethyl cellulose qis dua li ntawm methyl cellulose.